Lindberg PT Conversion

[bugfanatic]

I will be converting another Lindberg PT boat to RC, I know I've seen a couple people ask how to do it, would anyone be interested in me posting my progress as I go? I wouldn't start on it until late winter/early spring since my garage isn't heated so don't expect any posts soon.

[surfinkiwi]

most definetly, would be good to see the progress. Also while I am here do you know where I would be able to find plans to scratch build a pt boat. my son is onto me to make him one.

[bugfanatic]

It's still too cold here to get started - my garage isn't heated, but I'll be starting soon. As for plans, try these:

http://www.floatingdrydock.com/ptboat.htm

http://www.pt-boat.com/

Here's some more info for painting & research:

1) PT Boats at War - World War 2 to Vietnam. Norman Polmar & Samual Loring Morison. MBI Publishing ISBN = 0-7603-0499-9
2) PT Boats in Action. By T. Garth Connelly Illustrated by Joe Sewell. Squadron/Signal Publications Warships #7 ISBN = 0-89747-312-4

You can go to almost any bookstore & order using the ISBN or try online. I have built a few PT Boats & these books are invaluable. They show everything from early to late weapon installation to paint schemes to deployment & final history on each boat.

[bugfanatic]

Just to keep you posted - Ok, I've made some good progress since I had Friday off. I'll post some pics but so far I got my ESC & motors water cooled. then I got the motors & prop shafts & stuffing tubes mounted. Water pickups & exits put in. I even silver-soldered some oiler tubes to the tops of my stuffing tubes. Not bad for about 6 hours worth of work.

[bugfanatic]

Ok, here's some update pics. This first pic shows the layout of the motors, prop shafts, & oilers on the stuffing tubes.

[bugfanatic]

This next pic shows the water pickups near the middle of the hull in the center & the water exits at the rear. I plan on routing the water through the motors, through the ESC & then out the back.

[bugfanatic]

This pic shows the ESC after I milled the heat sinks to accept 2 water cooling lines. This is the Traxxas ESC that handles 2 motors & 2 battery packs. The motors that I'm using are Kyosho Magnetic Mayhems since I can get them in forward & reverse for counter-rotating props. The cooling coils on the motors are hand-wound 5/32 x 36" aluminum tubing from the hobby shop but you can buy these (like from Tower Hobbies) if you don't want to make them.

[bugfanatic]

This pic shows the motor area in a little better detail.

[bugfanatic]

I made my own motor mounting bulkhead, but look at what I could've bought had I looked before hand. This would have looked great in my hull. Oh well, what I made should work great. Just wish I would have looked around first. In fact, don't be surprised if in my later postings I've ripped out my homemade job & put this in it's place.

http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXGBG7&P=0


Also, here are the motor cooling coils that I made if you want to buy them.

http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXGBH3&P=7

[bugfanatic]

Ok, I'm just not happy with that plastic home-made bulkhead. I have some 1/8" aluminum sheet that would work perfect. It won't be galvanized & blue, but it will look much better. Out with the old....

On 2nd thought, maybe aluminum will transmit too much noise to the outside of the hull. I have some 0.188" thick fiberglass 'board' that will work better. I'll keep you posted.

[bugfanatic]

Ok, decided to make the new bulkhead out of fiberglas board. It will be quite sturdy & transmit less noise (see pic). Only problem is, I had to pry the old bulkhead out of the boat & it fought me the whole way. Somehow I managed to bend the stuffing tubes with the back of my hand while prying so those too had to come out & get replaced. So, I am now back to square one - an empty hull. While I was replacing the prop shafts & stuffing tubes I decided to silver-solder the dogbone cups to the top ends of the prop shafts since this area will be hard to get to & I won't be able to tighten a set screw if it loosens up on me. After I did this I noticed one shaft fit tightly the last 1/8" in the tube. This was caused by a little extra silver solder on the shaft. BRIGHT IDEA! I know what will clean this quickly - I chucked the shaft up in my drill & held a hand file against the shaft to smooth away the extra solder. What an idiot! I pushed a bit too hard, the shaft bent 90 degrees while it was spinning, & at several hundred rpm's it came around & smacked me in the cheek & took off my glasses. Lucky I didn't lose an eye & it hurts like heck. So, now I not only have an empty boat hull, I'll have a scar bigger than a postage stamp on my cheek. I'll give it another go soon & will keep you posted on 'Project PT'.

[bugfanatic]

I'm almost back to where I was before I had to rip out the old bulkhead. I also found out that the JB Weld comes 'unstuck' from the ABS hull when the hull flexes. So, I put the motors & stuffing tubes back in using some stiff silicone & I think this may be the ticket.

[bugfanatic]

I haven't posted in a while but I have been busy on the ol' PT. I'll get some pics up when I can. Anyway, I have lengthened the rudder tubes by inserting them with some aluminum tubing that has 3/16"ID & 1/4"OD. This will fit some 3/16" custom rudder shafts perfectly - not to mention that Dumas has some rudder throws made specifically for 3/16" dia rudder shafts. Finally, it looks like it's going a bit smoother than it was. I also have the rudders done & the radio box built. It may be hard to picture but I am suspending the ESC in the radio box by the water ins & outs. I have everything trial fit & so far it all looks good. I'll still need to get a lid on the radio box & fit the battery packs in place.

[bugfanatic]

Here you can see the larger-than scale rudders sticking out below the hull. Everything inside has been test fit & looks good. I put in the springs to hold in the battery packs & made sure all the wires were long enough.

[boatpoker]

Bugfanatic...

Your Modellooks Great!!!

May I Make A Few Suggestions That Worked For Me?....thanks...

My Most Recent Pt Is The 1/32 Lindberg You're Building. I've Equipped Mine With Twin 550 Air-cooled Motors And It Runs Like Bat Out Of He**!

Traxxas Sc, Etc...here's My Suggestions...to Reduce Vibration And To Protect The Prop Shafts (i've Upgraded Mine From The Stock Brass Units To Stainless Steel) I've Filledin The Areas Between The Prop Shafts And Hull, Inside And Out, Using West System Epoxy Found In Marine Supply Stores (this Stuff Holds Like King Kong!!) And Streamlined The Areas By Sanding...no Vibration There.

Although Your Pics Seem Preliminary I Noticed The Starboard Drive Coupler
Is Not Aligned Between The Motor And Prop Shaft. This Will Give You A Monster Vibration And Probaly Shake Her Apart At Torpedo Run Speeds.

Ps...great Job On Those Oiling Tubes!! Keep Upthe Good Work.

Boatpoker

[csligar]

Hey Guys,
I have just started in this hobby and just received a Lindberg kit I won on ebay. I am looking for all the pointers I can before I start the R/C building portion of the kit.
Were should I get my running gear? I would really would like to make it look real as I can but fast too.

THANKS in advance for any advise.

[carwasher]

nice model, now for the "but" if you can I would recomend making the prop shafts out of stainless steel. I used brass on mine ond a combination of motor torque and an underwater rock bent the shaft which siezed the motor. the seized motor quickly melted down the wiring and speed control almost catching on fire.on a second note fuse or circuit breaker protection would be a good idea but you speed control may have a thermal shutdown. if you fuse your motors seperately you could still have 1 motor running to get you back to shore.

[bugfanatic]

First thing is go to two motors powering two props & throw out the original Delrin gear stuff. You can get a Mack power setup here

http://www.mackproductsrc.com/index.htm

I use some modified motors with the original prop shafts. Stainless would make it absolutely bulletproof, but this is my 3rd Lindy & I've never had a prop shaft problem so I'll keep mine brass for now. Also, I have to address a few things. I kinda blew off the criticism but I need to point out a few things so that others aren't confused. The old setup near the top of this post was out of alignment, that was a few of many reasons that I remounted the motors to a new bulkhead. That old bulkhead was scrap that I was trying to cobb in. You can see the old vs new when comparing bulkheads in the pictures as it progresses. If you look at the new pictures, nothing is out of alignment. Trust me, it's perfect, look again. I too have filled in the stuffing tube areas & didn't use the supplied pieces. Constructive criticism is good, if you close your mind you stop learning, & I love to keep learning. What bothered me were the 'pointers' without the person really looking at what I had done or was doing. I've done that myself, been so into the whole 'pointing out what's wrong' that I missed some things, like the newer pictures that showed it had already been fixed. Don't get me wrong, the pointers were spot-on. They were just a little too late & I was puzzled as to why they were posted. In fact, I kinda lost interest in my PT for a bit..... but maybe I'll get back on it.

Also, another good thing to do is to build up the tubes where the rudders go through the hull. Raise them as far as possible to keep as much water out as you can by redrilling & inserting some aluminum or brass tubing so it extends above the water line. I also used some Dumas rudder arms to fit my new rudder posts I got from here:

http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXE517&P=7
http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXE518&P=7

[csligar]

Thanks,
How about the counter rotating props, should they turn to the inside or to the outside looking from the stern?. I now have another Lindberg on its way, so now my son will have one too. Should I get the Dumas running gear for their 33'' boat? Sorry about all the questions, but I am big in doing research.

Don't loose interest in your PT Boat I am VERY interested in your project,this article is the reason I joined. I have been building models for a long time but this is my first R/C Model, this is a big learning curve for me.

THANKS AGAIN
Colton

[bugfanatic]

Cool, thanks csligar, I appreciate the good words. You know, I'm not sure if it matters which way to do the props. That's a good question. Currently I have mine so that they turn inwards at the top - anyone know the answer to this one? The Dumas running gear is pretty good, but you could do it yourself & save a little $$$, especially since you'd still have to make the bulkhead to mount the motors. Plus, i didn't really like the Dumas speed control. I have extra bulkhead material, just let me know if you need anything. I could send a couple bulkheads with no holes so you can finish it yourself to fit the motors you're using. If you plan on using the stock brass prop shafts, there will be a 'bump' in the center of the boat that you will need to Dremel down where the new bulkhead will go. This bump is pretty obvious & is shaped like a .22 round-nosed bullet sticking straight up from the centerline. There will also be several lines on the sides that hold the original bulkhead in place that come off real easy with a sharp chisel. Just push the chisel down the wall & the lines will roll right off. This speed control replaces the one I have http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXGBK3&P=7 but it's a little pricey. BUT! It is already set up for 2 battery packs & 2 motors so you don't have to change ANYTHING. Keep me posted & let me know if you need anything.

[csligar]

Thanks for the advise and the bulkhead offer, once I have a plan put together I will share it with you and see what you think. I may take you up on the bulkhead offer.

I have checked out Tower Hobbies and read their Tech info on the Dumas speed control, they also don't much care fo it.

Also any thought on 3 bladed brass or bronze props?

I had the smae thought as you on the rotation of the props (turning inward )

THANKS for the help

Colton

[bugfanatic]

I am using the Dumas 3-bladed brass props. If you don't like that ESC you could always use a Super Rooster & water cool it.

[csligar]

I checked out the speed control you suggested and that looks like the way to go.
Do you have the part number of the props? trying to put everything down on paper so I can work out the budget. Any suggestions on the tranmitter and reciver?

Hope I don't wear you out, looks as if you have a handle on this stuff and I hate to buy the wrong things.

THANKS again for your help

[bugfanatic]

Not a prob, I don't mind at all. Here are the props (you'll still need a 1/8" drive dog):

http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXE500&P=7
http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXE501&P=7

I just use an old cheap 2-channel am radio. I haven't had a problem with radio noise yet. You can get some decent deals on these, just shop around.

[Kmot]

Bug: what a fantastic conversion you do! If I had seen this thread a year ago I would not have sold my 25 year old Lindberg PT!

[bugfanatic]

Thanks for the compliments. I don't really see it as being all that great yet, just 'in process' - but I try to do good work. I want to make it both solid & clean, those motors will move it quite well even with a little more weight in the radio box. It's not exactly scale, it doesn't have 3 props, but for what it is, the Lindy is pretty cool. You can really see the progress in the pictures after I make something & it just doesn't look right & I have to rip it out & do it over. Hopefully when people read this, they can avoid some mistakes I made as I went along.

[Kmot]

I just went to a scale boat club meeting at a pond and a couple fellows there had the Lindberg PT's converted sorta like yours. I saw one run, and man was it a nice performer!

[csligar]

Thanks for the info on the props, my list is growing.
Next question, what is the best way to put oilers on the stuffing tubes without denting or burring the inside wall? what do you think about making the engine room vent operational? What is the voltage of the Magnetic Mayhem motors? I have searched the web high and low for the specs, Tower Hobbies has some info but not any voltage info......Okay it was really 3 questions. I am sure I will have more. and I did give you a break over the weekend HA HA

THANKS
Colton

[bugfanatic]

Silver-solder the oilers on the tubes & THEN drill them out. Drill through from the oiler into the stuffing tube & then put your drill in the stuffing tube at the end to clear out the burrs & you'll have a pretty clean hole. 2nd, if you have an enclosed radio box or if you balloon the electrics, you can have a functional hatch. Personally, I'd rather water cool the motors. 3rd, I'm not sure about the voltage on the motors but they are made for RC cars so they work great on a 7.2v pack. I also know that they work fine up & over 12 volts too. I don't have much time right now to look, but here's Kyosho's link http://www.kyosho.com/accys/msmonster.html

p.s. on a side note, let me know if you want to water cool your motors, I have several extra cooling coils.

[csligar]

Thanks. I have given a thought to water cooling the motors, it doesn't look too tuff and I understand the machanics behind it. I checked out the web site for kyosho but they do not have the voltage specs. I was trying to figure out what type of batteries to run for a fast speed and about a 30 minute run time per charge. part of my plan was to get all the running gear and r/c stuff together before I assembled the model.
Did you use the Lindberg cupling shaft between the propeller shaft and the motors?

THANKS FOR ALL YOUR HELP
Colton

[bugfanatic]

I'll keep looking for the Kyosho motor info. The Magnetic Mayhem used to be called the LeMans 360 I believe. Maybe that will help out on the info search. As for the shaft hookup, I use a nylon dogbone & cup. You can buy them in a set, for 2 motors you buy 2 sets. The cup goes on the motor shaft & on the prop shaft. Let me find a link....

http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXE444&P=ML

[bugfanatic]

Don't use the plastic u-joint style as they don't hold up. Trust me on this one.

http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXJD72&P=M

[bugfanatic]

I didn't find much about the Magnetic Mayhem, but I'll post what I found.

http://www.yourzagi.com/motors2.htm
http://www.slkelectronics.com/ecalc/motors.htm
http://www.csd.net/~cgadd/eflight/calcs_motortest.htm

[csligar]

HOLY COW THANKS! looks like a science project. Did you say you used the original lindberg propeller shafts? I was looking at the Dumas bronze propellers and it looks like they need a drive pin. THANKS AGAIN it will take me a bit to read all this info.

[bugfanatic]

It's not a drive pin, it's called a drive dog. The Octura part number is OC4D. Let me find a link.... Any local hobby shop should be able to get this for you & they are under $3 each.

http://www.finedesignrc.com/hardware.asp
http://www.pirespreto.com/octura_catalog1.htm#DRIVE%20DOGS

I'm at work (on break) so I can't get a good pic right now. It fits onto the prop shaft & attaches with a set screw so it won't spin. It has 2 short tabs that stick out - which stick into the rect. cutouts on the center of the prop to drive it. Go to the electrics section & ask what a 1/8 drive dog looks like & they will help you.

[bugfanatic]

Here's a couple of pics

http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXE537&P=7
http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXDR17&P=7

[csligar]

I looked that up after one of your earlier post but I was thinking it was part of the U joint assembly, glad you set me straight. I saw them on Mack's web site. I saw the Midwest PT 109 today at Hobby Town, not bad looking, I think they could have done a better job on the detail painting. Getting close to making the initial hardware order.
THANKS FOR GOING THE EXTRA with the links and all.

Colton

[bugfanatic]

Hey no prob. Just let me know if you need anything. Also, you can make your own cooling coils for the motors. Get some 5/32 x 36" aluminum tubing from your hobby shop & wrap them yourself. Wrap them around a 'D' battery & they will fit nice & tight on your motor. When wrapping, keep pressure on the area that is bending with your thumb & follow it around as you wrap. This will keep it from kinking. Wrap one clockwise & the other counter-clockwise & this way the ends will be mirrored & match up to your water hookups. You may have to gently uncoil the stack ever-so-slightly to get it to slip over your motor. It's also easier to do before you solder the diodes on.

[CG Bob]

Bug - you may have your water pick-up tubes too far forward. Here's a picture of PT 188 that I scratch built at 1/32 scale.

[bugfanatic]

Bug - you may have your water pick-up tubes too far forward. Here's a picture of PT 188 that I scratch built at 1/32 scale.

Yeah, I noticed the original coils I had were pretty far forward - good eye. The later ones in the pictures are much larger & cover the whole can just short of touching the brushes. Of course I still haven't made much progress on this in quite some time, it has gotten put on the back burner for now. Just too many projects & too little time.

p.s. Your boat looks great. Scratch built boats can be quite impressive, as yours is. It even rides perfect without plowing through the water. Nice job.

[Tieben]

I will be converting another Lindberg PT boat to RC, I know I've seen a couple people ask how to do it, would anyone be interested in me posting my progress as I go? I wouldn't start on it until late winter/early spring since my garage isn't heated so don't expect any posts soon.
Good Evening ...Great work on Your PT Boat...If I were to install two Graupner 500 Speed Motor's,What ESC would You recomend? Would I need two ESC?Thank You Marc

[bugfanatic]

Sorry it took me so long to answer, I don't do much boat stuff in the winter. There are several speed controls out there that can handle 2 motors. There are others out there, but the Traxxas EVX which is made for the Villain is already prewired for 2 motors & 2 battery packs & is water cooled. It's pricey but well worth it.

[Tieben]

Good Mornig ... Thank You for the answer, I have learned a lot from Your Pictures and all. I'm going to Retire in5 months and then I will be able to build more than I do now, What Size motors do You use in Your PT's? From what I see Yoiu have done a Wonderful Job!! Thank You for all the Answers...Marc

[Tieben]

Its Me again....Were would I purchase this Traxxas EVX Speed controler? Thank You

[Tieben]

[QUOTE=bugfanatic]Sorry it took me so long to answer, I don't do much boat stuff in the winter. There are several speed controls out there that can handle 2 motors. There are others out there, but the Traxxas EVX which is made for the Villain is already prewired for 2 motors & 2 battery packs & is water cooled. It's pricey but well worth it.[/QUOT

I went on Line and Found them at a Very reasonable Price....Thank You Marc

[bugfanatic]

You're welcome. Since it comes already wired for 2 packs & 2 motors PLUS water cooled you can't beat it. Thanks for all the compliments!! I kind of learned as I went along. I had done one in the past when I was in college (20 years ago), & this time I'm taking my time & doing it right. No popsicle sticks for mounting servos!! If it looks wrong or doesn't fit right, I pull it out & do it again. As for the motors, the Magnetic Mayhems come in both forward & reverse wind so that you can run ounter-rotating props. They are a 550 size or some commonly call them an '05' motor. You may find them cheaper, but here's a link http://www2.towerhobbies.com/cgi-bin/WTI0095P?FVSEARCH=magnetic+mayhem&FVPROFIL=++

Good luck & keep us posted (wish I could retire soon). I should get going on my PT too so I can run it once it warms up. It' so hard - I just got an older VW so it takes all my spare time so far & my garage isn't heated. I'm actually a lot closer & should upload some pictures when I get a chance. This thread isn't dead, I'm just slow with the updates.

[MERLIN V12]

Can Any One Tell Me What Gear Comes With The Stock Kit? I Have One On Order.
Is It The Set-up Like The Blue Devil Has,gears And All That Cam Junk?
To Begin With I Just Need A Running Boat,than I Can Go Ape Later!
Thanks Guys

[bugfanatic]

The PT has a plastic bulkhead that you attach the Delrin gears to. The gears are noisy & run on plastic shafts so they're not very robust. By the way, you can add running lights to the Blue Devil real easy by using LED's. Remember, all the long words go on one side of the ship (starboard, green), the short ones on the other side (port, red). The Blue Devil tower even has enough room to fit a 9v battery up into it. One nicer thing about the PT is that you can turn while at speed & not roll over like the Blue Devil does.

[MERLIN V12]

Bugfanatic
Thanks For The Info. I Had The Blue Devil 38 Years Ago!
Is The Motor Included With The Pt 109 Kit Really Bad? The Reason I'm Asking Is This
Will Be My Rescue Boat For My R/c Float Plane. I Intend To "hook" The
Plane And Retrieve It If I Happen To Dump It In The Lake. I Always
Wanted A Pt Boat Anyway So This Is The Perfect Excuse.i Will
Rework It When I Get The $$$$$$$ And A Chance!

[bugfanatic]

Yeah, the included motor is a small Mabuchi style motor. Good for a toy but not for harder RC use. Actually, the weakest link is the gear train that gets mounted onto a bulkhead. It seems the gears want to seize onto the shafts even if greased & the shafts have a flat keeper head on them that likes to come off when it's WAY out in the water. If you want to do this on the cheap ( = low $$$) & use it as a dependable retrieval boat, go to Radio Shack & get 2 matching motors & hook them directly to the prop shafts with some rubber vacuum line. Get two 6 volt motors (these should look VERY similar to what comes in the kit since they are still a Mabuchi motor, only slightly larger) & don't mount the gears onto the bulkhead - just use the bulkhead to hold the motors. Much nicer to run, much quieter, & FAR more dependable. You'll see what I mean once you have these parts & the boat kit in front of you.

[bugfanatic]

p.s. I should also mention that if you mount the motors this way, you'll want to scoot the bulkhead closer to the prop shafts - don't mount it in the stock location. You can get rid of the guide ribs on the inside of the hull with a sharp cold chisel. Just push it down the inside of the hull & the ribs will peel right up. This way the flexible line style hookup will be as short as possible to keep the lines from 'whipping' as they rotate. An even better way to connect the motors to the prop shafts would be something like this http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXE444&P=0

[jdb88821]

I will be converting another Lindberg PT boat to RC, I know I've seen a couple people ask how to do it, would anyone be interested in me posting my progress as I go? I wouldn't start on it until late winter/early spring since my garage isn't heated so don't expect any posts soon.

I am in the process of searching for a Lindbergh Pt boat 1/32 scale. I wish to purchase one to put together and make it rc controlled. Do you or any other reader have some idea of a fair price to pay for a kit.

[jdb88821]

Hey Guys,
I have just started in this hobby and just received a Lindberg kit I won on ebay. I am looking for all the pointers I can before I start the R/C building portion of the kit.
Were should I get my running gear? I would really would like to make it look real as I can but fast too.

THANKS in advance for any advise.


I am looking to buy a kit for a 1/32 scale of the lindbergh boat. Could you give me some idea of a fair price to pay for one.

[bugfanatic]

Right now they have been going from $50-$75. Every now & then you might get a better deal - I paid about $60 for my last one.

[jhspring]

Hi Guys,

I just found this conversation and I have a couple of things that may be of interest. I built the Lindberg Blue Devil a couple of years ago, and the counter-rotating props on real destroyers turn inwards from the bottom, I think to avoid cavitation. I checked on the 1/1 USS Kidd in Baton Rouge. The real PT's, of course, had 3 props, all spinning in the same direction. Btw, while the Fletcher does roll in a most alarming fashion, if ballasted correctly, you can put the rails under and it pops right back.

I bought my PT 109 kit on eBay aobut 6 months ago, then promptly bought a "new" old house and so it sits neglected (sigh). I got mine cheaply, but they are currently fetching over $120 on eBay. HOWEVER, if you look at Tower Hobbies or eHobbies, Lindberg apparently intends to re-issue the kit in April for around $65-$75, which is good news for all of us.

My intention is to use 3 Mabuchi 380's like I use in my r/c airplanes. They are really cheap, couple of $ each, and should provide plenty of oomph in direct drive. I make all my own shafts and such too, and us oiling tubes like bug, but I normally use 1/16" music wire as shafts as it doesn't bend as easily.

If I ever get my model room up and running again, I will send some pics. Enjoying the thread, thanks. Jeff

[MERLIN V12]

I Just Received My Lindeberg Pt 109 From Tower After Months Of Waiting On Backorder. It Arrived In Perfect Condition But There Are Some Issues. 1)the Prop Shaft Tubes Are Slightly Bent And Will Have To Be Replaced. 2) The Wire On One Side Of The Motor Was Off.
3) If You Want To R/c This Boat The Motor And Running Gear Included Are Useless. See All The Great Tips In This Forum On The "right" Way To R/c This Boat, Bug Is Dead On. The Rest Of The Model Has A Lot Of Potential! I'm Off To The Store For Parts !

[bugfanatic]

Merlin, thanks for the kudos. I really want to 'do it right' this time. You know, take the time, make it robust & dependable, make it look good inside & out. Too bad I can't get it done as soon as I want to. I've learned a lot by taking my time & not hacking it together. I found out there really is no way to attach a fiberglass bulkhead to that ABS plastic. Nothing really works good. I thought that silicone would be my best bet, but I was wrong. I've tried everything from super glue to JB Weld & nothing will put up with the hull flexing but still hold everything together without a dogbone coming out of the cups. I may just have to poke something through the hull like some smooth head bolts or something - would really rather not do that. There's got to be a way, & that's where I left it. Had to put it down & figure this one out. I figured I would have had it on the lake last summer, but another boat & other projects (another VW) delayed it - hopefully I can get back on track this summer & close this with some great running pics. Too many projects, too little time.

[MERLIN V12]

As A Last Resort Try "shoe Goop" It's Really For Repairing Shoes But So Far I Found It Sticks To Plastic,wood,rubber And Light Metal Better Than Silicone. Also As Far As Silicones Go Permatex Is Better Than Ge.i've Used It On Real Boats!

[Micho523]

Try using gorilla glue. It will bond anything porus or not, and gets stronger with moisture!

[bugfanatic]

I actually got a bottle just for this reason, but wasn't sure it was going to stick to ABS. I'll have to try it.

[WingRider]

Would these motors be suitable for the 109 conversion. I found them for a really great price!! Anyones thoughts please. :confused:

This last batch of 545 motors has much heavier windings than the previous motors. These motors are putting out a lot of RPM at lower voltages. Works well with 6 to 12 volt batteries. A pair of these motors could easily power a 1/96 scale cruiser or large destroyer. R. F. I. (radio frequency interference) supression capacitor included.

* Rated for 12 volts max, will turn on 1 cell ( 1.2 volts ) with no load.
* Stall current at 12 volts - 5.0 amps
* Draws 1.25 amps running direct drive with a Radestock 1.5 (38mm)" 3-bladed prop at 12 volts (3950 RPM).
* Can Size: 1.32" (33.5mm) diameter, 2.2" (56mm) long.
* Shaft Size: .125" (3.1mm) diameter, .3125" (7.9mm) long.
* Mounting holes: use 3mm machine screws.
* Weight: 170 grams.

[bugfanatic]

Yeah, those sound like drill motors. Should work good.

[WingRider]

Thanks for getting back so soon. I can get these for $7.00 each or $2.00 for each additional motor. Again thanks for the help. Will be getting my 109 kit in next week. I'll be converting it over to a late war torpedo/gun boat.

[MERLIN V12]

Well it seems i can never do anything easy (or cheaply). I got 2 Johnson 600 speed motors for $14.00
i couldn't resist. Now i need a speed controller ($$$$$$$$$$$) and 2 batteries($$$$$$$) and a wiring diagram to put the ESC,batteries and Motors to the RX. Bug do you have a wiring diagram before i burn this up.......................

P.S. i set up the stock gearing and included motor for a Goof.......it was so loud my wife came in screaming to shut it off ,LOL.
Thanks John

[WingRider]

Merlin, let me know what you came up with for the ESC & batteries. i would appreciate a copy of the wiring as well. Thanks

[MERLIN V12]

As soon as i get somthing i will FWD it to you. The ESC I'm afraid will be more than the Boat.
for battery packs check-
http://www.cheapbatterypacks.com/main.asp?sid=321371
Mike will
will make us anything we need...look under custom packs.
John

P.S. fooling around i ran a 600 speed thru the stock gears with a A/C 7.2 -700 mah pack................The gears melted in 6 seconds....really they are gone !

[bugfanatic]

I cheated & used the ready-to-wire Traxxas ESC. As for wiring them yourself, you need to decide if you want your batteries in series or parallel. If you do series, you double the voltage to the speed control which then directs them to the motors. See what your ESC can handle as far as voltage in, that may tell you right there what you can/can't do. Parallel will keep the voltage the same but double the amperage. Then, decide if you want your motors in series or parallel also. Just a guess but you'll probably want to run the batteries & motors in parallel. Others can jump in here as to what they feel is best. Sorry I haven't done a follow-up in so long. Too many projects - and my bug is project #1 right now. SO, as soon as I get back to my PT, I promise to keep you posted.... right now I've done the radio box & have a new bulkhead ready to put in (I want to try that gorilla glue).

[bugfanatic]

p.s. Yes, the stock motor & gear setup really puts out the sound! Sounds awful, doesn't it? I can't even describe the shrill vibrating plastic & gear mesh sound it makes, definitely unique. I will attest to the fact that it (the stock setup) quiets down considerably once in the water though. That hull just seems to amplify any noise from the bulkhead like a bell when it's out of the water - that's one of several reasons why I made a new bulkhead & connected the motors direct to the prop shafts.

[MERLIN V12]

I Think This Is How It Should Look .for Two Totors A "y" Cable Should Work...i Think

[MERLIN V12]

Two Motors..........totors, Gee I Did Not Even Start Drinking Yet!

[WingRider]

You know, this is all greek to me. I'm really confused about the batteries, connectors, what type of ESC ect. This is the first electric R/C boat I've put together. I really appreciate all of ya'll's help. By the way, I have a BAD Ship Models DE on the building board now. I can build em, just don't know how to set the power trains up. There are NO R/C boat clubs in my area. Again thanks.............

[MERLIN V12]

Wing
This is my 1st Boat as well. I do electric RC Planes.With a single AC motor you just put in the matching ESC and your done ! With Boats it seems that the ESC is most important because when running slow the ESC can over heat and burn up as well as burning up at high speed . If we are to run 2 Motors
the ESC (with reverse)will have to take something like 60 to 90 Amps to live.
Bugfanatic used the ready-to-wire Traxxas ESC. and I believe Super Rooster has one for two Motors. As i find out more i will post it .All i know is the ESC will be the big $$$$$$$$$$$$$ item. How big is the DE you are building?
John

[WingRider]

Merlin,
Thanks, I need all the info I can get. The DE is a 1/96 scale from BAD Ship Models, is 38" long with a 4" beam. Kit is all wood, has all running gear except motors & R/C equipment. Check them out at this site http://www.badshipmodels.com/

[stephen1965]

Hi i'm a new member and I just found this site and have read every one of the PT posting. I wish I knew about some of the mods bugfanitic has mentioned when I did mine. I also have one of the 32 scale Lindberg kits. I have owned it for close to 26 years. I converted it over to R/C in 1994 and LOVE IT! Mine has two Rhino 505's, direct driven through real u-joints,(very smooth) using a mechanical speed controller, (burned up a couple electronic contolers figuring out what would work) two 7.2 batterys are wired in series and man does it go! Only about 8 inches of the boat is in the water at full throttle! I have to be carefull when turning it hard as it can throw the rear of the boat right out of the water. My motors only get a little warm but the speed controler gets real hot! I had to cut out some of the plastic from under the cabin to give it room to cool. I used the stock tubes and props and have had very little water come in. I put rubber o-rings in between the u-joint and a flat washer that goes up against the stuffing tube. The o-rings are sqeezed in tight and keep slight tension against the flat washer which dramaticly restricts water from coming in. I just wish I would have made the modification to the rudder tubes that I read about here, cause that is where I get my water. I mounted my motors on aluminum plates that I made. I used RTV to attach them to the bottom of the boat and have not had a problem with them. My boat sounds like good also, a nice low humming noise at any speed. I will be buying another model soon and will be iplimenting a lot of the same modifications I read here. I'll keep you all posted if you are intrested!

[WingRider]

I'm using GreatPlanes T 600 electric motors. The problem I'm having is that the motors have so much torque that they have destroyed the shaft supports outside the hull. I seem to be having a lot of high frequency viberation through the shafts, anyone have any ideas? I'm using Gruppner U-Joints, stock shafts and props. I think it best that you try out the conversion in the water and not dry. I'm using the XL-1 ESC as described above and one 7.2 2400 MaH battery pack. All help appreciated.

[stephen1965]

I do not run mine out of the water because of the no-load vibration. I have broken one of the shaft supports doing that. As far as your vibration goes, make sure your motors are aligned/inline as close as possible with the shafts. also need to make sure your shafts/tubes are not bent and are lubed. If all these things are good then try filling your tubes with grease. Since grease is so much thicker it will absorb some of the vibration but it will also absorb more of the power due to the thicker consistancy. Hope this helps!

[bugfanatic]

I have found a great little tip that works here - sorry I never posted it. Take the 2-piece plates that hold each prop stuffing tube at the hull & replace it with hot glue. It not only dampens a lot of the vibration but it can be sanded to make a nice transition where the tube exits the hull. Plus, you can still use the shaft supports that are near the props for a somewhat scale appearance. Really, I'm almost done with my bug & I will be posting pics & tips & such when I can get back on my PT boat. Sometimes one project moves another to the back burner. p.s. - I also found a great glue to hold my motor bulkhead plate to the hull. Marine Goop. It's like the old shoe-goo or more commonly GOOP but it's marine grade & stays flexible. Use it on the light side as it will make a melt mark on the outside of the hull since it attacks the plastic like model glue does. BUT - with that on my bulkhead & hot glue on the stuffing tubes my boat is QUIET when I run it up on the bench.

[MERLIN V12]

I Broke the Gruppner U-Joints i ws using. I thought a $10.00 (a piece)U-joint would hold up. Besides 2 600s are too fast (only 1/6 th of the boat is in the water) i will use my EPA to cut the throttle back.
I used the stock plastic motor mounting plate with no problems.

[MERLIN V12]

High speed run

[MERLIN V12]

pic 2

[MERLIN V12]

hs 3

[stephen1965]

Boat looks great! That first pic shows the front way up! Ithink those 600s kick butt. What is your run time and what battterys are you using? I'm getting about 3-4 minutes of real fast speeds then it progressivly slows down as the batterys wear down for a total run time of about 10 minutes

[MERLIN V12]

Thanks! I have a 3300 Mah battery hump style pack from Cheapbatterypacks.com
it is 14 ounces. I'm moving it up to the motor mount because the stern is below water level at full power. I got about 10 min.s before i blew the u-joints. I bet the battery would last 30 min.s if i play the throttle.

[bugfanatic]

Looks great!! Nice pics! On my first PT conversion I used those U-joints only to have the same problem you did. I went to the Dumas ball & socket dogbone style setup & have never had a problem since.

[MERLIN V12]

i'll look into it bug

[MERLIN V12]

My brother in law took the pics and wants full credit so here it is.
TOM took the pictures!

[MERLIN V12]

Hey BUG
My Traxxas xl-1 will not go into reverse! Fwd is ok and the light changes to
RED from GREEN when i move the stick but no motor run. Can only REV stop working on these? It was working at the lake early in the day. Any ideas guys.
Thanks John

[MERLIN V12]

sorry i can't help it

[MERLIN V12]

ok now TOM feels better!

[WingRider]

Did you a least let Tom run the boat?

[jhspring]

Hey BUG
My Traxxas xl-1 will not go into reverse! Fwd is ok and the light changes to
RED from GREEN when i move the stick but no motor run. Can only REV stop working on these? It was working at the lake early in the day. Any ideas guys.
Thanks John

John, some of the speed controllers (esp Traxxas) are designed for cars, and in race mode reverse has to be locked out. You have to program them For/Rev or For/Brake. I'm thinking that if you had an electronic glitch, the esc may have reverted to race mode. Only thing that makes sense to me. Regards, Jeff

[MERLIN V12]

Did you a least let Tom run the boat?
NO !

[stephen1965]

Thanks! I have a 3300 Mah battery hump style pack from Cheapbatterypacks.com
it is 14 ounces. I'm moving it up to the motor mount because the stern is below water level at full power. I got about 10 min.s before i blew the u-joints. I bet the battery would last 30 min.s if i play the throttle.


John here's something to think about. I moved my batterys up to the motors yesterday and found that when I turn it hard at full speed the front end dives out and down and the boat lays over on its side some unstead of turning. I think it is because with the weight of the motors, radio gear and now the batterys farther forward that the rear has no weight to keep the back of the boat planted and most the weight is in the forward section, up in the air, so when I try to turn, the boat rolls over on its side and goes straight. So today before I run it I'm going to put the batterys a little farther back and see if I can find the sweat spot. I have a digital camera but I'm ignorant on how to use it and down load the pics to here. I'll get it figured it out and post a few at-speed and turning shots.

[MERLIN V12]

stephen
if you are using XP you can right click on the pic, select resize picture,custom and change it to 600 x 400 and you will be able to post it using manage attachments...................now to the battery! I tried mine in front of the mount and the bow was plowing water at slow speed (the 600s still get it on plane)i did not get to try it at the motor mount today. Car in shop $1600.00 for repairs. Will get to pond ASAP. I was going to use two 2400 mah batteries but i did not want to rip out all the electronics so i went for the (cheap,yea right) Custom 3300 mah. I'll let ya know!...send pics
John

[bugfanatic]

I agree, sounds like your esc has locked out reverse. I suppose you could have rev burnt out, anything's possible. Also, if the PT plows too much at slow speed, you can get a length of real small brasss 'L' channel & epoxy or CA it at the hull transition line. If you look at the full size boats they had this & it keeps the water down around the nose. Just CA it in place, rough it up a bit so paint will stick & paint it the same color as the hull. http://www.battleshipcove.com/Assets/Images%20-%20General/News/gallery-news-kit-pt/news-kit-pt617-b.jpg

[MERLIN V12]

Thanks for your responces JHSPRING and BUG.i will look into the lockout idea,but with my luck it's fryed. gets a wee bit hot in there. i will add water cooling and the strakes(or what ever the boat term is) when i get this sortet out. I built this as a rescue boat for my Float Plane but this is too much fun as is. I'll let you know how i make out. Maybe tues night if TOM the slave driver lets me off the roof.He did find a great spot for planes and boats 5 min.s from his house!

[stephen1965]

I agree, sounds like your esc has locked out reverse. I suppose you could have rev burnt out, anything's possible. Also, if the PT plows too much at slow speed, you can get a length of real small brasss 'L' channel & epoxy or CA it at the hull transition line. If you look at the full size boats they had this & it keeps the water down around the nose. Just CA it in place, rough it up a bit so paint will stick & paint it the same color as the hull. http://www.battleshipcove.com/Assets/Images%20-%20General/News/gallery-news-kit-pt/news-kit-pt617-b.jpg

I used .100 Midwest square rod styrene, on my hull transition line. It is light, flexible, easy to work with, close to scale and costs $2.30 (tower hobbies) for enough to do one boat with some left over. I just bought some yesterday for my next boat. Putting this on mine helped fan the water out away from the boat unstead of it coming up the side. It also helps the boat get up on-plane a little. Hey I moved my battery packs back about 1 1/2 inches and it helped with control at speed and turning, but it still wants to flip over on its side during high speed turns. Im going to put them back were I had them to start with which is the in front of the stock battery holder. The boat handled good with them there before.

[stephen1965]

Took pics of my boat but I having problems getting them from my files to this location. I,m using windows 98 and I dont know much about it. I'll keep trying.

[MERLIN V12]

STEPHEN
IF YOU WANT SEND ME THE PICS AND I CAN CONVERT THEM AND POST THEM FOR YOU.
ZATHRAS@OPTONLINE.NET
JOHN

[MERLIN V12]

This Is A Pic Of Steve's Sweet Looking Pt. ALL THE FOLLOWING PICKS ARE OF HIS BOAT IN ACTION

[MERLIN V12]

nice

[MERLIN V12]

....

[MERLIN V12]

it moves

[MERLIN V12]

.....

[stephen1965]

Try using gorilla glue. It will bond anything porus or not, and gets stronger with moisture!

Where can I buy Gorilla glue?
Thanks
Stephen

[stephen1965]

Hey guys Im thinking of building my own rudders for my new boat. I'd use hollow tubing for the pivit shafts. The shafts will double as water intakes for the speed control and motor cooling lines. My thought is to cut a hole in the tube behind the propeller so the water will be forced into the shaft from the props push, forcing the water through the tubes, to hose's conected at the top. I'm also thinking of putting the returns near the back of the boat on the bottom, so as the boat is moving, it will also be pulling the water from the tubes.(siphon effect) I'm thinking of using ether stainless steel or brass and I can TIG/(stainless) or solder/(brass) the rudder blades onto the tubes. Well what do you guys think? Over the top? Making these is not a problem. If they work I would be happy to make more. Please fell free to give me some feed back!
Thanks
Stephen

[bugfanatic]

Stephen, I made my own rudders & they turned out great! (I used brass rods with steel rudders) I don't see why you couldn't make them out of hollow stainless. That's a pretty good idea. You can easily silver-solder the stainless together & not have to mess with the tig. Those would look really nice! Also, don't forget to drill out the rudder holes in the hull & bushing them with some tubing so that the tops of the rudder holes are above the water line a little more. This will help keep your hull dry.

[bugfanatic]

p.s. you can buy Gorilla glue from hardware stores like Menard's or Lowe's.

[bugfanatic]

Keep the pictures coming, they look great!

[MERLIN V12]

I Used The Stock Rudders With An "o" Ring At The Base And Filled The Tube With Salt-water Proof Wheel Bearing Grease. I Get The Water From Mashing Reverse And A Stern Wave Breaks Over The Stern Or Turns That Have The Tail Underwater.....................
Moving Things Fwd To "fix" That.

[stephen1965]

Stephen, I made my own rudders & they turned out great! (I used brass rods with steel rudders) I don't see why you couldn't make them out of hollow stainless. That's a pretty good idea. You can easily silver-solder the stainless together & not have to mess with the tig. Those would look really nice! Also, don't forget to drill out the rudder holes in the hull & bushing them with some tubing so that the tops of the rudder holes are above the water line a little more. This will help keep your hull dry.

I'm going to use your idea on the silver solder, That sounds like the easer way to go. I just happen to have some too! I read your tech-tip earlier in this thread about the rudder shaft mod and the cooling lines, that was what got me thinking on making these. I'm also going to use a piece of sheet plastic .080" to support the tops of the shafts. When I get this done I'll take some pic's of it. Did you make your rudders the same size as the one's in the kit? I'm thinking of maybe a tad larger? I've all ready got a line on a Traxxas evx 14.4 volt speed controller and my nephew is BIG into RC trucks and said he has a set of new ball bearing motors that he's modified that I can try out. He said they will run longer and have more torque then most 21 turn motors. I'll keep you guys posted! Messing with this stuff makes me feel young again!

[stephen1965]

I Used The Stock Rudders With An "o" Ring At The Base And Filled The Tube With Salt-water Proof Wheel Bearing Grease. I Get The Water From Mashing Reverse And A Stern Wave Breaks Over The Stern Or Turns That Have The Tail Underwater.....................
Moving Things Fwd To "fix" That.
Is the water getting in around the rudder covers? If it is, you can seal them down with RTV. Mine are held in place and sealed with black RTV. Do all painting first! (paint and silicone dont mix!) After installation of the covers, allow the RTV to dry then the excess RTV can be trimed away with a razor blade or hobby knife.

[bugfanatic]

I made my rudders slightly larger. Not much taller, but I made the blade area larger. I just went through this thread front to back & really enjoyed it. I just got out of the garage with the bug so I have nothing left in me to go back out there & work on the PT for now. It's 93 degrees here & muggy so I'm dyin' right now. Had to come back inside for a bit. When I read this thread it gets me antsy to get going on the PT again. If this thread keeps going just think how many 'finished' pics we can get of peoples' projects. Seeing other peoples' boats finished keeps my interest in high gear. A guy at work says that he can take digital video for me so I'll have to take him up on it when I get there.

[MERLIN V12]

Is the water getting in around the rudder covers? If it is, you can seal them down with RTV. Mine are held in place and sealed with black RTV. Do all painting first! (paint and silicone dont mix!) After installation of the covers, allow the RTV to dry then the excess RTV can be trimed away with a razor blade or hobby knife.


MY RUDDER ACCESS COVERS ARE GLUED SHUT. I HAVE 5 SCREWS ON MOUNTING POINTS TO HOLD DOWN THE DECK. WHEN I'M SATISFIED WITH THE WAY THE BOAT RUNS I'LL SEAL IT WITH A SILICON GASKET SO I WILL STILL BE ABLE TO REMOVE THE DECK.THE WATER WASHES OVER THE BACK AND ENTERS THE (LITTLE) SPACE BETWEEN THE HULL AND DECK AS WELL AS THE REMOVABLE CHART HOUSE PIECE. I RAN THE BOAT TODAY ON ONE ENGINE WITH ONLY ONE PROP RUNNING.THE BATTERY (14 OZ.) WAS AGAINST THE MOTOR MOUNT.
IT TAKES 6 FEET TO COME ONTO PLANE INSTEAD OF 6 INCHES WITH BOTH 600S RUNNING! AT SLOW SPEED THE BOW IS SPLITTING WATER. SO AGAIN THE DECK WILL NEED TO BE SEALED.THE "WATER "I'M TAKING ONE AMOUNTS TO A THIMBLE FULL ANYWAY.BOAT IS FULLY PAINTED ,I JUST NEED TO PUT THE FINAL DETAIL WORK AND MAYBE THE CREW.
MY TRAXXAS XL-1 WILL NOT WORK IN REV. AND GETS HOT RIGHT AWAY.
ME THINKS I HAVE TROUBLE.

[MERLIN V12]

I Like The Way The Boat Turns. I Can Stay In Aprox. A 6 Foor Circle At Med Speed.i Have Duel Rates Because At High Speed I Can Put The Pt On Its Side With Only One Prop In The Water And The Torpedo Tubes In The Water.

[stephen1965]

Well guys it finally happened! SHIP WRECKED! Its not really that bad but the rudder up grade is going to happen real soon! I was running it in my nephews swiming pool trying out a set of 3300 nhim batterys when the left u-joint came loose, the shaft slid back,the prop caught the rudder locking the steering in straight forward. At the same time the speed controller (mech) stuck in full forward so the boat went full speed into the side of the concret wall. Guns, crewmembers, misc parts went flying from the impact. The boat capsized and the removable deck started to sink.The hole time both engines are in full scream! End result no more sailing in the pool! Thank god there was no damage to the electronics. Did loose one rudder in the pool somewhere, but like I said it's time for new rudders and rudder shafts. I'll glue the parts and crew members back on after I fix the rudders later this week. All and all I'd say I was lucky. I'll keep you all posted while its in dry dock.

[MERLIN V12]

Well guys it finally happened! SHIP WRECKED! Its not really that bad but the rudder up grade is going to happen real soon! I was running it in my nephews swiming pool trying out a set of 3300 nhim batterys when the left u-joint came loose, the shaft slid back,the prop caught the rudder locking the steering in straight forward. At the same time the speed controller (mech) stuck in full forward so the boat went full speed into the side of the concret wall. Guns, crewmembers, misc parts went flying from the impact. The boat capsized and the removable deck started to sink.The hole time both engines are in full scream! End result no more sailing in the pool! Thank god there was no damage to the electronics. Did loose one rudder in the pool somewhere, but like I said it's time for new rudders and rudder shafts. I'll glue the parts and crew members back on after I fix the rudders later this week. All and all I'd say I was lucky. I'll keep you all posted while its in dry dock.
THATS WHAT HAPPEND TO THE REAL pt 109

[Jf8054]

I am new to R/C and I want to thank all of you for the great tips. Bug, the photos are great of the interior and I will almost exactly copy your style. I do have a few questions about the steering mechanism. Where did you put the servos and how was the connecting arm placed? Photos would be optimal but any suggestions of manufacuters or components would be great. Any help would be appreciated thanks.

[bugfanatic]

Thanks for the compliments! I haven't mounted the radio yet, but the rudder arms are listed somewhere back in the post I believe. As soon as I make more progress I will surely post more pics. I will only have 1 servo for the rudders since I'll be using an ESC for motor control.

[MERLIN V12]

Hi Bug and friends
As we all know i blew up the $20.00 dollar plus Grapuner U-Joints i was using. I guess the 2 Johnson 600s with a 3300 MAH battery is too much for them. The Dumas ones don't look that strong with the "dog bone" thing! Any ideas? I'm using 1/8 in shafts and the motors are also 1/8th. by the way if your looking for scale speed 2 600s are too much.The boat has to be throttled back to look real and lower speeds KILL the speed control(too much heat). While we are on it what speed control will handle 2 motors that is not the Traxxas XL-1(THAT LASTED 30 MIN.S).
John

[belltowerbrett]

Hello all.I have been reading this thread with much interest as I am about to build this model for R/c.I see you are having some problems with ESC's when running twin 600's.If you can source it Robbe make a ESC that can handle twin 700's and is designed for marine use.

[bugfanatic]

The Dumas ones should be plenty strong. Really. They are a brass cup with nylon dogbones. I've never seen one of these break. Here's what I was talking about - http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXE444&P=0

[Jf8054]

Why not attach the motors directly to the drive shafts and eliminate the dogbones or other connections. The motors could be mounted in a way to have minimal movement and they would be more rearward for better weight distribution. Please give insight, thanks again.

[bugfanatic]

I've seen motors mounted like that with some rubber hose directly from the motor shaft to the prop shaft. It works, but I'm not sure how 'bullet proof' it is. Maybe others who have done this can add some more info. Seems like the rubber would become brittle over time. With my luck, they would break when the boat is about 300 feet out in the lake!

[belltowerbrett]

Using that type of coupling works well in relatively small scale ships that are run at scale speeds and is very dependable as long as care is taken in the choice of coupling material and you have a quality installation.I have seen a variety of types ranging from silicon fuel hose to small diameter thickwall rubber hose,but I probably wouldn't recommend it for high speed use on this scale or above,especially with motors of the 500 - 800 size due to the high torque.I think you'd be better off sticking to a good solid drive coupling or maybe going to a flex shaft drive.I get the feeling that jf8054 means an actual solid joint between the motor and shaft.Could be done - but I would think that the alignment and balance would have to be near perfect.Depends on the application.What does everybody else think?

[bugfanatic]

Yeah, you'd have to get it perfectly balanced with no runout. A flex drive would be much more forgiving & quiet.

[stephen1965]

Hi Bug and friends
As we all know i blew up the $20.00 dollar plus Grapuner U-Joints i was using. I guess the 2 Johnson 600s with a 3300 MAH battery is too much for them. The Dumas ones don't look that strong with the "dog bone" thing! Any ideas? I'm using 1/8 in shafts and the motors are also 1/8th. by the way if your looking for scale speed 2 600s are too much.The boat has to be throttled back to look real and lower speeds KILL the speed control(too much heat). While we are on it what speed control will handle 2 motors that is not the Traxxas XL-1(THAT LASTED 30 MIN.S).
John
Sorry it took so long to get back to you, but as far as your speed controller goes: get on ebay and go to the section on R/C trucks and do a search for: Brand-TRAXXAS then below that in Key Word put- EVX. This ESC is designed for two motors. You should be able to get one between $65-85. Good luck and let us know how you make out! Stephen...

[GMA451]

Just thought I would include my Lingberg PT-109 and my experiences with the kit. It is a great kit, but as has been said you definitely want to scrap the running hardware that comes with kit. I've built two Lindberg 109's and the last one I used the Traxxas EVX ESC with twin Traxxax motors and it runs great. I water cooled the motors and speed control using a small water pump mounted under the bow. The water pump is great since when you slow down, the motors and ESC continue to receive cooling water [note cooling water exiting stern of boat in attached photo]. The water pump, lights, and sound are all powered by a 9.6 volt battery mounted under the front deck. Since the kit has again been re-issued I purchased two more, and may build one more after I finish my Dumas 48" PT-109, which I'm converting to a late war PT-596, of course that's only if I can stay focused on one project!

[bugfanatic]

Wow, that looks great! Nice pic.

[stephen1965]

Looks Great! looks almost real! It would be neat if we could get a few of these together for some action shots. I'm building a second one now for my daughter to run with me. I've had mine with two others once before and we had a blast running them up and down a canel in Rome NY. They looked real running at speed. I have video some where of them. Picked up another EVX ESC today for $56 bucks this one is going to replace the Mechanical one in my current boat that is pictured earlyer in this thread.

[Jf8054]

Im looking for the EVX ESC as well and I cant seem to find it for less than 100 in good condition. Where did you get yours for 56 bucks. Also what is the deal with the "Marine" version ESC. Is it just the standard with a water cooled head, or are the electronics different? Thanks

[stephen1965]

Im looking for the EVX ESC as well and I cant seem to find it for less than 100 in good condition. Where did you get yours for 56 bucks. Also what is the deal with the "Marine" version ESC. Is it just the standard with a water cooled head, or are the electronics different? Thanks

Back-up a few messages on this page to one from me. I outlined how on E-Bay I found both of mine. I mentioned above that I put down Traxxas for a brand name but I have since found that just putting EVX in the key word box opened up the search area giving me more EVX's to bid on. Good luck!
I forgot to mention that the water cooled head is the only difference between the two EVX's.

[Jf8054]

Thanks,
Jf8054

[Jf8054]

It seems to me, according to most posts, that the Traxxas ESC/EVX is the way to go as well as the Titan Marine 550s. My question is should I use the entire Villain EX electronics and motors in a direct drive with dogbones or use it as in the Villain with a reduction gear box of about 2:1 ratio. I've spoken to the guys at Traxxas who said the reduction gears are necessary to reduce load on the motors for longer life. According to most posts direct drive is the way to go. Are the Traxxas guys too cautious using reduction gears or is there really nothing to worry about with direct drive. I want my boat to go fast, but I don't need it to fly 4-8 feet in the air with a good wake. Please give me some tips from your experience. Thanks.

[stephen1965]

My personnel opinion is you want torq motors due to the amount of power needed to get your boat up on plane and keep it there. There are lots of motors out there that would work but costs are a factor. Ball bearing's ($)are better than brass bushing (cheaper). How many winds the motor has also plays a part (more winds less power, longer run time.Less winds more power shorter run times) Weather it is a single turn (more off the line power, less RPM) or double turn (less torq more RPM) My nephew who is really into 4wd R/C trucks said that for what I'm doing a motor in the 20-23 single turn area would be my best bet for run time and good power. So I took his advise and bought two new Titan 550's. ($20.09 w/shipping, e-bay) Another motor I still might buy are the Magnetic Mayhems. I'm no expert! so it would not hurt to ask a hobby dealer that deals a lot with R/C cars/trucks what they think and use your own judgement. Now on the reduction- I run my two motors in my old boat direct drive. My nephew checked them with a inferred heat gun after a full run and told me they were well within operating temp (what ever that temp is). So again do some research and keep asking questions, that is what I do. Remember to have fun with it.

[MERLIN V12]

I USE 2 JOHNSON 600 SIZE MOTORS.A LOT OF WINDS. THEY WERE $6.00 A PIECE. THE BOAT DOES LIKE 30/35 MPH DOESN'T LOOK REAL.I HAVE TO USE 1/2 SPEED TO LOOK SCALE! IT HAS SO MUCH TORQUE IT BLOWS THE U-JOINTS. NOW AS FOR TRAXXAS XL1- I WILL NEVER BUY ANYTHING FROM THEM AGAIN. WARRANTY-SURE IF YOU USE IT ONCE FOR 3 MINUETS WITHIN 30 DAYS YOU ARE OK.....IF YOU WANT IT REPAIRED AFTER 30 DAYS IT'S $15.00 PLUS $5.00 s&h AND AN EXTRA $25.00 IF YOU CHANGE THE PLUG.$45.00 FOR A $50.00 SPEED CONTROL. NO THANKS,IT BURNT OUT AFTER APROX 25 MIN.S TOTAL.....A LITTLE RICH FOR ME.I CAN'T BELIEVE THE MARINE MODEL WOULD BE ANY BETTER. I WILL COME UP WITH SOMETHING ELSE.

[Jf8054]

I was wondering if you could tell where you obtained the water pump you used and where it could be obtained, thanks

[GMA451]

I was wondering if you could tell where you obtained the water pump you used and where it could be obtained, thanks

I have purchased three water pumps from the following company. They work great, and produce more than enough water even when operating on less than 12 volts. I installed a filter prior to the pump to keep debris out of the pump. I also ordered a water pump from Tower Hobbies, however, it proved to be far to noisy. Graupner also makes several water pumps, however, I have not purchased any of them.


http://www.greylor.com/catalog.htm

[GMA451]

Just a follow up. I should have listed the particular model that I've been using. It is the 12 volt Miniature Gear pump model.


www.greylor.com/catalog.htm

[Jf8054]

Bug, Could you please tell me where you obtained your rudder shafts, rudders, and tubes for your boat, thanks.

[bugfanatic]

Sure, here's a quote from one of my old posts - "I have lengthened the rudder tubes by inserting them with some aluminum tubing that has 3/16"ID & 1/4"OD. This will fit some 3/16" custom rudder shafts perfectly - not to mention that Dumas has some rudder throws made specifically for 3/16" dia rudder shafts." What I did was go to the hobby shop & get some aluminum tubing & some 3/16" diameter solid brass rod. I cut the tubing to length & inserted them into my hull to lengthen the area the rudder shaft sits in to reduce the amount of incoming water (this raises the top of the rudder tubes higher & possibly above the water line). I milled a slot in the brass rod & silver soldered the rudder into the slot. I cut the rudder out of stainless I believe & once the rudder was soldered into the slot in the rudder shaft, I then put the rudder shafts into the extended shaft tubes & marked the length where I needed to cut them with a sharpie. I then pulled the rudder shafts out, cut them to length, & then put them back in & tightened the rudder throw arms to the top. I know this was all custom, but it actually went pretty fast. Maybe 1/2 hour total. Just make sure to make the rudders the same & take care to remove burrs from cutting before fitting. If you can't get this type of stuff from a local hobby shop, try www.mcmaster.com. Search under brass rod, stainless sheet, & aluminum tubing. Or, if you'd like, I can make you a set.

[bugfanatic]

One more thing, make sure to put a 3/16" 'wheel collet' (not misspelled) on the rudder shaft above the rudder. These are used to hold wheels of RC planes onto the axles. This will make a great bearing surface between the rudder shaft & tube & will help keep grease in & water out. Without it, the top of the rudder will scrape back & forth on the bottom of the rudder tube. Then make sure the rudder throw sits on top of the tube but just loose enough to move the rudder without binding.

[Jf8054]

Thanks, again, Jf8054

[bugfanatic]

I was asked a very good question & really want to post it. Forgive me for cropping it a little: "I will be running the stinger motors (7.2max) with the new XL-10 by Traxxas. Most likely in direct drive based on your suggestion. The motors are I think 20 or 21 turns. Do you think I could use the Dumas 1/8 props you used even though I'm not able to run on 14.4 like your set up? I would like to run scale but at times hit the throttle like you suggested."

Those motors would turn those props perfectly. They really seem to be the perfect size. PLUS - being brass you can always tweak a little more pitch into them at a later time if you want to. I may have been running on 14.4 with my old setup, but each motor was only getting 7.2 because of the split so I'd have to say that your setup should be good depending on how you split it. Remember, if you run 1 battery pack & 2 motors you can either split the motors in series or parallel. In other words you either keep 7.2 volts & drop the amps or you drop the voltage & keep the amps. My 2 cents: with today's battery packs being 3000mah, you could split them to run like 2 1500mah battery packs by running the motors in parallel. So I think your setup is perfect. I really was impressed how my old boat performed & I'm anxious to see how this one will go since I'll be about 2x the battery power I had in my first setup.

[Jf8054]

I just received the tower hobbies props numbered LXE500 and LXE501. They are not what is pictured on the web site. They are better, the main difference is no drive dog is required as they fit the 5-40 thread of the Lindberg PT. You may need to cut the length of the shaft for perfect fit. I've decided to go direct drive with a couppler at the angle of the stuffing tube, minimal vibration. I'm water cooling using a Honda windshield washer pump and 9.6 v battery. Pictures to follow, thanks all.

[coberg1]

Hi, was wondering if I could get some opinions on a couple things. I threw away the running gear that came with it and am installing brass three blade 1.25 inch twenty five degree props, eighth inch stainless shafts with bronze bushings in quarter inch stuffing tubes to universal joints to 2.5/1 belt drive gear reduction, to reedy spec 19 quad mag motors(reduced to zero timing). They will be independantly powered by a tazer 19 esc and venom 3000 ma six cell nihm packs on each motor.
I am not looking for very high top speeds (though I suspect she will a bit faster than scale)
My questions:
One shaft is ever so slightly out of true, .003 inches (measured on concentricity guage) I read that most shafts have some wobble, is this excessive? It feels a little stiffer when turning by hand directly but can't tell them apart when turning the u-joint. Oh, shaft length is about four inches.
2:
what kind of runtimes can I expect given it will probably not be wide open all the time?
3:
Will this setup run hot? or is this plenty of power for the size boat?
4:
When alighning the motors to the shaft, given the use of universal joints, how much misalignment can be forgiven? If it looks straight to the eye is that close enough?
Appreciate any help anyone can offer, thanks in advance.

Chuck

[bugfanatic]

coberg, sounds like a real nice setup.
1) 0.003" out of true is great. Better than most boats. They'll loosen up a bit too once ran. 2) Not sure about the run times, depends on a few other things besides motor & battery like weight of boat, load on the props, driveline friction, & whether your props have been sharpened. 3) Should be plenty of power, as for hot, do you mean hot like good speed or hot like temp.? Speed should be good, temp could be better if you water cooled the motors & esc. 4) U joints are very forgiving but the further you get off center the more vibration you'll get. If they look straight, they're great. If you can use a straight edge to check them, then they'll be perfect. I've seen a lot of scale boats with quite a driveline angle that ran just fine.

[coberg1]

that was a fast response! thanks! the shaft was my biggest concern, they turn very freely in the bushings with almost no drag. But there is a small bit of binding in the one that prompted me to check the straitness. Was worried about excessive vibration at high speed.
You mentioned sharp props. Will that make a big difference in efficiency and runtime?
The motors are 19 turn 540s that run about twenty three amps at load, I was hoping for at least a thirty minute runtime, still don't really know what I'm doing with this stuff, only my second rc project. The first being a tamiya missouri conversion, so this level of power and speed is a whole new thing.
The props at 1.25 inches are a quarter inch smaller than the ones that came with the kit but will be spinning roughly seven to nine thousand rpms at full speed after the belt reduction reduces the motors 25,000 rpm rating(also somewhat reduced by resetting the timing to zero so I can reverse one of them)
Looking at you guys boats looks like you are getting some very impressive performance! Nicely done! hope mine comes out as nicely.

[bugfanatic]

Yeah, sharp props will help, at least sand them down with some 600 grit so they aren't as-cast. Those motors with those batteries should easily see long run times. If you divide your mah on your battery packs by the amps the motor will use, plus the fact that they are geared down means some impressive run times. Only time on the lake will prove it, let us know what you get. Sounds like you did a great professional job on the drivetrain.

[coberg1]

Still installing, shafts are in secured and braced. working on independant motor mounts. Took your advice already and sharpened the props. I replaced the skegs with 1/4 inch id brass tube with .035x1 inch brass legs, VERY strong, could probably run right over a rock and not bend the shafts, (hopefully). The way the belt drives are set up would make water cooling jackets problematic, hoping heat won't be a problem. May have to put a fan in.

[Rex R]

computer fans come in assorted sizes and can be powered by a 9v battery.

[coberg1]

Lets see if I can post a pic. Thought you guys might like to see my take on this. Two completely independant powertrains individually fused should get me back to shore under most circumstances. The mounts are laid out and mostly complete. Still have to drill mounting holes and screw down the beltdrives. A two inch wide strip of styrene down the middle with velcro on that and the batterys should let me shift weight for efficient trimming.

[bugfanatic]

I think it looks great! Be careful with those plastic u-joints though. I had a set just like those in my first PT years ago & they came apart. I had to go swimming to fetch it which would have been ok except for the fact I was on my way to work & just wanted to have a quick little morning run. Under load, my u-joints flexed & the center popped out. Now I use dogbones & cups & have never had another failure. If interested, I can post sites of some metal u-joints. http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXMM86&P=7 http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXGE52&P=7 http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXGM96&P=7 Just make sure they fit the prop & motor shafts you're using.

[coberg1]

The shafts are extremely smooth and freespinning, hope that doesn't happen. those joints are from loyalhannah dockyard per his recommendation and are different diameter from end to end. I think they would be hard to replace. The output end of the beltdrives are 1/4 inch and the shafts are 1/8th.
For the initial lubricant in the stuffing tubes I'm thinking slick 50 or some other teflon treatment like that. Hoping to reduce drag even more.
Mabe have to be careful about jamming the throttle up too fast eh?

[coberg1]

successful bathtub test today. Way too fast for a pt but what the heck, oughtta be fun when I get it out on the lake. MAN do those propellers move a lot of water.
Using 75/90 synthetic gearlube. pretty heavy stuff and still getting a little oil spray from the ends of the shaft. Do you guys cork the top of the oil reservoir? I think that would eliminate most of it.

[coberg1]

you can see how big the braces are on the skegs here, VERY rigid. This thing is as smooth as I could have hoped for although the motor I reversed is warming up more than the other.

[Rex R]

was reading about 'motor timing' (still not quite understanding all of it yet) do these motors have their timing set at anything other than 0 degrees? if I understand it right if the normal motor is set at 10 degrees then the backward motor should have its timing set to minus 10 degrees.

[coberg1]

Well, just got back from a small local pond. The last time I was there it was very clean, when I pulled in today it was loaded with weeds. Since it is shallow enough to wade to any point in I figured this was a good spot to see how strong the drive train is.
Performance is flawless. A little faster than scale but not too much. After adjusting rudder travels handling is very realistic with the front third coming up out of the water and no squatting.
Run time was about thirty minutes and the motors and esc's stayed REASONABLY cool. Not hot enough to worry about. What really amazed me though was the weed cutting capacity. About five times she got bogged down, the first time I'm thinking to myself there goes something. But drove her into shore pulled the weeds off the prop and put her back in the water. After my experience with my missouri and it's fragile little drive train this really makes me happy.
This running gear setup was a little more expensive but IMO very much worth it!

[coberg1]

was reading about 'motor timing' (still not quite understanding all of it yet) do these motors have their timing set at anything other than 0 degrees? if I understand it right if the normal motor is set at 10 degrees then the backward motor should have its timing set to minus 10 degrees.
I filed the timing notch off and reset both to zero.

[bugfanatic]

Sounds like you had a great first run!! Good job! Glad to see it performed like you had hoped. As for the oiler tubes, I just leave mine open. I really don't see too much come back out of them. In fact, I make more of a mess filling them than the boat does when it's running.

[coberg1]

Got the hull closed up and painted. Supposed to be a really nice day tomorrow, gonna take it out and play, I'll post pics from the water if anyone is interested.

[bugfanatic]

Of course we're interested!

[coberg1]

finally! Third time out now, the wife can't drive a boat or take a picture so sorry about the quality.

[coberg1]

would post a couple more but the file size limit is too restraining.

[coberg1]

Think I finally am getting the hang of this resizing thing. This shot shows trimm with one battery pack as far to the stern and the other as far to the bow as I can get them, so far as good as I have gotten it. Looks pretty much like a real pt boat does.

[coberg1]

I think I solved the oil leakage problem. It wasn't coming back out the filler tube, you may have misunderstood. It was leaking around the bushings, my fault, when I glued them into the ends of the shaft I was worried about getting glue on the inside of the bushing so didn't get a good seal. Had to refill the tubes every run. Started putting in slick 50 and it plugged them up very nicely, also seems to have equalled out the friction very nearly completely.
Before adding the teflon, at the first throttle increment, the absolute lowest setting, the motor that is polarized correctly would start spinning very slowly and smoothly while the one that is reversed would bog down and jerk into motion rather roughly. One more click on the throttle stick and both would be running roughly the same slow speed.
But now they both start very smoothely and slowly at the first click on the throttle, with the reversed motor moving slightly slower, by the second increment you can't see the difference at all.

[bugfanatic]

That is a great picture - looks scale! Very nice. Do you have a tachometer? I have one that I use for plane & boat props. If you have one you can check to see just how far off they are from each other. Thanks for the pics!

[coberg1]

Thanks for the compliment, no tach. I did make another discovery about the unequal spinning though. Most likely from my first shakedown run through the weeds but the portside beltdrive drive pully was slipping on the shaft, I think I have been running on thrust from one motor. Pulled the motor and beltdrive, resecured everything and put it back in, it was spinning before but I must have been loosing a crapload of thrust.
Gonna take it back out tomorrow and see if there is any increase in performance.
Here are some more shots from the same run though. She turns very tightly with just the stock rudders. possibly from shortening the shafts and setting the skegs further from the rudders.

[coberg1]

Wanted to show how tight the turn was but keep getting a load error when i try to upload the pic, I'll try again tomorrow.

[coberg1]

Wanted to show how tight the turn was but keep getting a load error when i try to upload the pic, I'll try again tomorrow.
Think I got it, she turns pretty tight.

[coberg1]

last one. Just blasting on the throttle she stirs a little water up.

[coberg1]

Okay, had to put this shot in too, this wake looks to cool.

[swithers]

Hi all, Have just found this posting GREAT reading ... I have just about finished restoring a pt150 i got from a car boot in march , it was just a wrecked shell when i got it, have had lots of fun rebuildind her. have a look at this link and see what you think ( have to say she looks great on the water ! size is 48" http://photobucket.com/albums/v482/swithers/. Thanks Steve

[bugfanatic]

OK, it's been a while but I'm making progress. Actually, I think I'm going backwards. I reread this thread & really want to incorporate some great suggestions. I removed the shafts & stuffing tubes & I'm replacing them with stainless. I'm still thinking about using brass stuffing tubes just for the natural lubricity with a steel shaft since I'll still have a lot of strength in the shafts themselves but I'll probably make them all stainless. I just used my die & put 5-40 threads on the prop ends of the shafts. So now I'm back to making some new shafts & stuffing tubes. Also, I really liked the way coberg strengthened up the skegs that hold the stuffing tubes. PLUS, I want to use longer shafts to relocate my motors farther forward. Also, I need to pull out & relocate the water pickup tubes. So, I guess 'progress' is relative. I may experiment a little, I have 3 hulls to play with right now so I can afford to make some guesses. I welcome your input!

[jjoohhn]

Reading all your posts on the Lindberg PT boat brought back some memories. I stumbled across this kit around 1994-5, maybe stumbled is not the correct word, as it was the largest box in the store. paid around $70 for it, took it home, opened the box and was impressed by the size, but not by the drives.

Anyway, life intervened and so six months later I revisited the box, gathered all the material I could on the real thing and then, by sheer luck dropped in a hobby store here in SoCal. Looking around in the boat section, there lay two self contained drives. Motor, gear redution housing, outer prop shaft tube, bearings, packing, inner shaft and two blade prop, all in one neat package.

I cannot remember the manufacturer, I believe it may have been Graupner, but they were a little pricey, around $100 each. You could change the motor if you wanted, it had standard spacings, and you could change the prop Only mod I did was to drill a pinhole in the outer tube near the top and used a needle point grease gun to pack the propshaft tube, never had a leak, just half a pump each time I took it out.

Bought one of the early electronic speed controls. Used two six volt packs, wired in parallel, held in by velcro straps on ply boards siliconed (the type used for aquariums, it is absolutely top notch). Fabricated brass rudders, with extended stainless tubes, coupled both rudder heads together in the rear well and used DuBro nylon flex control rod to operate. Servo trays, bulheads and motor thrust blocks all held in by the silicone.

A note on handling: This is only what I did, it worked for me. By placing the two batteries, one each side, it requires much more energy to "lift" the ouside of the hull in a sharp turn, and by placing the two motors "inside" and up as close as possible to the underside of the decking, they tend to act like gyros, again, increasing the effort required to displace them. During all of the high speed manuevering left and right and full throttle turns, it never exhibited any tendency to tuck, skip or dig. But then again, I could just have got lucky.

Balanced the completed boat at 1/16th behind the step. It seemed to replicate the real boats "on and off" the step behaviour, along with the "nose down" off the step. Had the watercooled motors, used the outer scale mufflers as the pickups, and routed the exit through the scale exhausts. Unfortunately you could not see anything behind the boat at speed for the rooster tails. So I question if it was worth the extra work, although I never had motor overheat problems.

Installed nav lights (red and green LED's), hollowed out the mast top light, white LED and made the wires the supports for the mast.

My 4 year old at the time really enjoyed it, (so did I), We have a fair size (400 yard X 300 yard) duck pond at the local airport and you could creep up behind a duck to within a couple of feet, the duck would startle, max the throttle and literally it would keep the bow right on the ducks butt until it got airborne, so acceleration was quite sufficient. Top speed, probably in the 15 mph range, but I can't authenticate that.

My wife at the time asked how much money I had in the "toy boat", atound $100 was my reply. If she only Knew!

So, back out at the local airport, bored, trying to discharge the batteries, going around, quite quickly in circles, about 8 feet from the bank. All of a sudden there is a loud bang, the boat jumps up out of the water, slams back down, sounds of gears stripping and motors running wild. Boat heads out, slowly, listing, really sluggish. Finally manage to egg shape circle back to bank. It hit a rock just under the surface, I had run that boat all over that lake, never hit a thing, but oviously missed one thing until now. It bent the port shaft at a 45 deg angle, stripped the gears and cracked the gearbox, jammed the port rudder aginst the hull, sprung the deck and cracked the hull. Ouch. But the silicone did not let go, amazing.

Saw another one in a hobby store that was going out of business, picked it up for $40. Got divorced, never saw it again. Ces't la vie.

[coberg1]

Hey Bugfanatic. Haven't been around for a while, just saw your post. Curious why you want to make the shafts longer? Don't forget the longer you make them the easier they bend. I purposely made mine as short as was physically possible. I think they are about five inches if I remember right. That .003 inch out of true on the starboard shaft is the last bit of vibration. Gonna swap that shaft out, I found a local place that specializes in this stuff so will actually be able to check it out before I buy. With the beltdrives and shortened shafts the ONLY thing you can hear on the water is the whine of the motors themselves. Very nice! Also capping the top of the refill tubes has eiminated the need to refill the stuffing tubes, ten runs and still full. The caps create a vacuum inside the stuffing tube that will not allow the oil to go out around the bushings.

[bugfanatic]

I balanced the hull with the running gear in it & I just want to try to move the motors & bulkhead a little farther forward. I don't want them too much longer, just over 1" at most. Stainless shafts in stainless tubes will still be stronger than brass/brass at the stock length. This also moves the assembly forward so I can get to it easier through the deck opening for maint. I can't move stuff too far forward or I won't be able to get the batteries out.

[U812]

Great thread and build Bug. I mostly build subs and jets but I have a bug for Navy ships and boats as well. Some how my clever wife got me a Lindberg 1/32 PT for Christmas. Much to my surprise.

Wanted one ever since they first came out.

I love the water cooling idea. I just need to know where to get the pump. The rest I can do as I am an avid scratch builder and have 25 years of building under my belt.


Thanks a bunch,

Steve

[bugfanatic]

You can get any 12v pump like from a windshield squirter. I personally don't run a pump & just have some intakes on the bottom of the hull that flow when the boat moves forward. Thanks for the compliments on the thread - too bad it's taking me a LONG time to get it done.

[U812]

Thanks Bug. No it's not. Doing things the right way is more important. Then you'll have years of enjoyment and not some boat stuck out in the middle of the lake!

Working on mine now. What a nice break from subs. You want to talk about taking along time. Try a sub.

Steve

[U812]

BTW. Happy new year!

Steve

[U812]

Well I finished mine I got for Christmas a few days ago. Only problem is the ESC I ordered from Tower two weeks ago has not showed up.

It was an easy build. Painting and weathering took more time than anything else. Now when I take my subs out I have a target.

Here's a few pictures in my pool. Better know as my RC sub test tank.

Steve

[U812]

another

[U812]

And yes it has lights too.

[bugfanatic]

She's a beaut! Nice job.

[U812]

Thanks a bunch Bug!

Stalking the mail man!

Steve

[ptboater]

Hi All this is Thomas,
Im new to this forum,just discover you yesterday.Well i have also the lindberg Pt ,bought it from ebay about a year ago for 75 euros and allready build (about a month ago for first time i found this kit in a hobby shop in Athens and for what i now those kits never come to Greece in the past).I had plans to build it as a super detailed static model.For that reason i found plans and scale drawings before i discover that the only think i had to keep from this model was the hull and that have also wrong shape!! But there is a god out there and ITALERI will release a PT 109 kit in 1/35 scale in the end of this year so i will go for it as a static model and i decide to convert my lindberg to R/C and here are some questions for you.Im thinking to put two 550 mambuchi motors watercooled ofcourse , replaceing the prop shafts and the u joints with better ones and then "play" with the props.One other thought is to put 3 400 type motors with 3 prop shafts since the original PT 103 class had three engines.What option do you think it will go faster ,in both cases i will use two batteries in order to keep the weight down and also try to lightweight the boat by replaceing the deck and maby some of the superstracture ,yes this baby is heavy and we dont want this.Do you know anyone that have convert it with 3 motors and what was the result?

[U812]

I just used two sp 400s and it has better than scale speed with the supplied props.

It sounds to me like your on a good track and your idea's will certainly work. My motors aren't water cooled and I've had no problems. It's best to use dog bones over the universal joints as Bug here will tell you.

She's off scale all right but with a little work she can look the part and it makes a good, cheap, RC PT.

Good luck my friend and have fun.

Steve

[ptboater]

Hi Steve,
Well to tell you the truth i like scale speed but i want to make this baby really fast.I have no idea about how it will go in the water.The faster boat i have is an intercepter 650 with a standard 550 motor,i have also change the shaft and add a u joint (thats why i tryst them but ill have in mind the dog bones).One day i decide to go faster and put a thunderbolt motor and i can tell you it was fast maby faster that it had to be but had lot of vibrations so now the idea is to make my PT free of vibrations.I have some ideas in mind to make it run smooth and fast. What i want to try is to have reverse between the motors.Do i need to use two speed controls for that or i can find a speed control that can reverse the motors?

[U812]

Using a single ESC is fine as long as it's rated for your amp draw and voltage. No need for two. I'm using a Hitec EZX-r rated for 65 amps and for 6-7 cells. 34.95 from Tower hobbies and it's excellent. You can turn the props so slow you can count the revs.

Steve

[coberg1]

http://i35.photobucket.com/albums/d197/coberg1/modelwarshipsgallerypt-08.jpg
Nice boat Steve, gee, lost track of this thread. Been building a couple static models but saw TWO Lindbergs on a shelf at the hobby store today. Do you guys know if this kit is actually still in production? I heard they discontinued production for a while but decided to make some more recently.
Btw, going through the thread I realized I never posted a pic of my finished boat, sorry but the one above is the closest closeup I have on my computer. No lights though! Now I'm jealous! :D

[coberg1]

Also, I have an insurance settlement coming soon, gonna spend a little of it on a 16th scale pt from Mosquito boat hobbies, How about a five foot long model with three 700bb motors?

[U812]

It sure sounds good to me. Go for it. Also put a link up to the boat so I can take a look.

Yes it's over again for the Lindy PT. I was lucky to get one but my firends at the local hobby store ran one down for me.

Thanks a bunch,

Steve

[coberg1]

http://www.geocities.com/mosquitoboat/ptkits.html

Here's the address for the large scale kits, I guess that was what you meant by putting up a link?

[U812]

Wow. What a beaut! Thanks a bunch!

steve

[Jf8054]

Thanks for all the great posts. My boat is almost finished, hopefully pictures to follow. My question is what is the best way to put the decals on, specifically the two large PT-109s on the bow of the boat. These will get a significant splash and I dont want them to fall off. The boat is painted with a plastic primer, flat grey, as in the 1960s movie PT-109. On previous trials in the water, quite water proof. Now I have to put on the decals and I need help, what do you guys think, Thanks, Jf8054

[coberg1]

I don't usually bother with decals but here's how evrybody I know does it:
First you have to spray a gloss clear coat where the decals are going, you should probably do the entire hull so that it looks even later, once you have the gloss down apply your decals, let dry thoroughly, then spray a clear dullcoat over everything. As well as sealing the decal from the water this also hides the clear margin around the decal.
If I were doing this I would run a strip of wide masking tape around the water line and around the top edge of the hull hanging up to act as a paint shield to avoid having to shoot clear and dull over EVRYTHING. Though most of the guys that do this do the whole boat.

[Jf8054]

Thanks, Jf8054, any other opinions.

[bugfanatic]

coberg1 had it perfect. I like to trim my decals a little closer to get rid of that clear witness area around the decal but I'd mask it off like he said & spray with some Testor's clear flat.

[coberg1]

The reason for the clear coat first is to make the clear decal border invisible. It may seem like a pain in the behind and unnecessary but if you put a decal over flat finish paint it traps a lot of air from the uneven surface of the paint beneath the decal and you will still see it after you overspray the decal with the dullcoat. For static display only models a lot of guys will spray Future floor wax over the surface that recieves the decal so as to give the decal a smooth surface to a