Sport PT-19 (Speed 400 Outrunner)

[PipesCS]

I started this thread in the wrong place and decided to put it here.

This years project is a PT-19 electric that I worked up the plans from a friends gas .10 version. I wanted a model that was small enough to sit in the seat of my pickup put together and fly on the way home from work. (40 inch wingspan)

I had Top Notch Products in Tennessee cut the short kit (around 52 Parts) which came to around $31.00 after shipping and handling. I tried to bring the model to a point that a modeler who had the tools and experiance to build an ARF could build this in about a week

Total weight with a 450 E Flite Outrunner/20 amp speed control/1650 ma 3cell li poly was 23 oz. it is a floater with the capability of speed on call

It is turning into an excellent tail dragger trainer and second plane.

This is the first prototype on the plans and the second kit cut.

The model is what was called stick and tissue construction in the old days and is much lighter that a lot of lite ply construction while still being plenty strong.

[PipesCS]

I forgot to mention I am not a modeler who is in this for the money

I would be more than glad to convert my drawings on this and the Gee Bee D Model to a PDF format and E mail them to anyone who wishes to go to Kinkos and make copies

John at Top Notch Products would be more than glad to cut and ship to anyone as I make no claim on the work exept that you enjoy it.

[PipesCS]

One of the changes I made in the conversion of the original design was to make the cowl part of the fuselage so that the motor could be installed with two screws thru the nose block. I also made the cockpit a removable hatch(made up of 5 pieces in the short kit) to give easy access to the battery compartment. The motor and and battery hatch are held down by 1/8" rare earth magnets from Radio Shack.

[PipesCS]

This is a better shot of the battery compartment and the motor hatch prior to thinning it down.

[PipesCS]

Spoke with a print shop on cost to reproduce plans from a PDF should anyone wish a set. The price varies greatly. I shop I deal with in MD carges 29 cents per square foot of the final print where Kinkos gets .75

[PipesCS]

As I said at the start this is a sport model to be built with basicly an Exacto-knife, sanding block, straight edge, glue, and covering tools.

This is the first prototype wing after joining the two panels with 2 ply doublers. I have started the 3/32" shear webbing with is cut to fit between the upper and lower spars. (If you look close you will see I forgot that the grain should run verticle. I did go back and replace it.

The leading and trailing edge is made from standard square balso and sanded to shape.

[PipesCS]

Although I am still working this model on the second prototype of this model I am getting distracted by the start of the D model Gee Bee.

The Gee Bee uses the same wing with different tips and a larger fuselage. It is powered by a larger motor so the battery compartment has been enlarged to take a 2100ma.

One note

I have figured out how to convert my CAD drawings to a PDF and should be able to E mail them to any one that would like a "free" set. they are about 3 x 5 foot and kinkos can print the file full size for about .75 cents a sq ft.

The photo shows the 2nd prototype PT 19 on the left of the Gee Bee

[PipesCS]

One last note on this project.

The short kit can be bought from Top Notch Products for around 31 Dollars.

I am doing the clean up on the drawings and should be able to email a printable copy to anyone interested by the end of the month

As part of the testing for the Gee Bee I went ahead and added lead till the model weighed 30oz and still had good flights with it limiting the motor to 11.5 amps max on static runs. Managed 10 min flights with no problems.

[PipesCS]

I have kind of let this thread fall by the wayside as not too many people even seem to look at it. But for those that have and continue to, I would like to say this PT 19 is the best airplane in my stable. The original design by Bob Somers in Maryland and My Electric Conversion continue to Fly and Fly well.

I loaded mine up with lead to bring it up to 34 oz as that is the weight of my Gee Bee. I warmed up with the PT to be ready to test the Gee Bee.

With its wide gear and long tail it is a great flier for me at lunch. I leave it in the truck seat for weeks so the covering looks rought due to the heat but I get to the field at lunch fly two flights and go back to work.

I keep my batteries in a thermal lunch pouch with icepacks to keep them cool in the truck during the summer to protect them from the heat. These were taken when I had a photographer out to shoot the Gee Bee Test hop.

[cpc]

Is a copy of the PDF still available? A dxf would also work.

Thanks

Charlie

[PipesCS]

The PT 19 was my first effort at and electric and a very small short kit was worked up for me by Top Notch Products in Tenn.

I never really did to much after the first two kits were cut except fly it. The original has been flown well over a hundred flights now and has been used as a test bird for some of my other projects.

The construction is dated to say the least. It was a gas model originally that weighed almost 40 oz with the electric weighing in less than two pounds.

A few people have shown interest in it and I decided to re do it to make it easer to build using the newer concepts that laser cutting offered.

You can still cut all the parts on your own if you want to as they are on the plans.

The plans are still for free should you want to send me an email thru the messaging service on this site. If you order the short kit from John at Top Notch products he will also print the plans for you. I believe he is cheaper than kinkos.

The biggest change was to take the fuselage from a square stick and tissue design to a sheetwood rear fuselage. This gave me the chance to round the corners to make it a little more pleasing to the eye. By moving the aileron servos out into the wing it gave me the room to mount the servos upright in the battery compartment. This allowed straighter push rod runs to the tail.

The new fuselage came out only three quarter oz heavier than the stick built and is not only much stronger, it was built in about an hour of my time.

[PipesCS]

The original tail and wingtips were made up of balsa laminations formed over plywood formers that john put in the kit.

Having built a Gee Bee by Mad Rob I decided to try his method of construction. I don't think it is as strong but having over a hundred flights on the PT I don't feel you need it.

The new method is simply gluing up the cut pieces over the plans (Use Wax paper)

I built the tail feathers in less than thirty min. All parts of the tail and tips are now in the short kit, including the diagnal bracing which has the beveled ends cut. They fit perfect.

[cpc]

Like the new fuselage. Sent you a PM.

Also need info on Top Notch

Thanks

Charlie
Columbia, pa

[PipesCS]

One other change I made was to lengthen the nose to help balance the extra weight added to the tail.

This is one of the original stick built fuselage next to the new one.

[PipesCS]

The original design had the aileron servo in the wing center section which really cluttered up the wing mounting area.

It worked so well on the Model D Gee Bee to move them out to the wing that I did it on this one also. I am using the Hitech 55 series.

[PipesCS]

I realized on this thread I missed a lot as I felt no one was interested. Now that I am getting interest I need to go back and show some of the things that are not too common.

The landing gear is made up of the laser cut pieces to do away with the need to rip a slot in a small landing gear block. You simply lay up the pieces to make the blocks

[PipesCS]

These are photos of the original blocks that were really too narrow

On the later models I added wider areas for the screws and straps to anchor the wire.

[PipesCS]

Had a little trouble getting these to upload

As I say the newer ones are wider to take the screws and straps

[PipesCS]

Gave up on trying to load the old photos that show the gear blocks. Finished the sheer webbing, landing gear blocks and center wing sheeting.

In these photos you can also see the servo mount area and the paper tube to route the servo lead through

[PipesCS]

They build much faster than the original. May not be as strong but I have yet to find the need for the extra strength

[PipesCS]

Finished building the wing tonight.

All the major parts are now assembled with the next step to sand every thing to its finished shape, install the pushrod tubes in the fuselage. put on the covering and finish up.

[PipesCS]

Thought I would add a few more of the early photos showing the newer construction.

The lower nose block is shaped then hollowed out leaving a wall thickness of around 1/4 inch. The lower block is epoxied between the nose and F-2 to carry some of the stress from the motor being screwed to to the front plate.

The blocks are built up from sheet stock.

after gluing up the nose blocks and glueing them to the fuselage I use a coarse grit belt sander to rough shape the plywood nose plate.

[PipesCS]

Covered the wing today and put on the decals. Need to hang the ailerons.

Also stripped the wing to recover the original prototype as it is getting pretty rough to look at.

[PipesCS]

Hey CPC

When you go to build your wing if you cannot find good hard balsa for the spars I would recommend that you go with bass wood.

I have the same spars in my Gee Bee models and have broken 2 this year in take off incidents. (Crashes)

[PipesCS]

Managed to get a lot of time in the shop for me this weekend.

Started covering the fuselage later today.

Have to make a run to the local hobby shop tomorrow as I am out of yellow covering for the original prototype that is under going over haul. It has been in the air since Nov of 2006 and spends a lot of time in the back of my car as I fly it at lunch.

The photo of the motor mount and battery compartment are of the prototype showing the 450 motor and a 2000ma "Common Sense RC" brand battery. It is the largest battery I use in the model. A 1600 will also fit as it is the same size exept thinner.

I have yet to fly the prototype on a 400 E Flite motor but know it will do well as the 450 is a bit much so I prop it for only 10 amps.

[PipesCS]

I am not getting too much time in the shop and as you can tell my kids are trashing the shop anyway with a summer art class

The old reliable PT 19 number 44 is almost overhauled. It only needs a set of new ailerons put on and it will be ready to go. It has been in the air since Dec of 06 and has well over a hundred flights.

Number 77 is getting there. Next step is to put in the wing bolts, detail out the rudder stripes and hang the tailfeathers and tail wheel. Motor has already be fitted and it and the speed control will slip back in as soon as I cut out the monocoat from the cooling holes

I have been flying an ARF at lunch the last few days and must admit I miss number 44 as it much more fun to fly.

These photos also show the increase in Dihedral in the new wing.

[PipesCS]

Starting to get number 77 ready to fly. did a taxi check today to check out the radio

Found a bad rudder servo and will need to replace it later in the week.

Just down to the detailing now.

[PipesCS]

Weighed both models and found they weigh within a half oz of each other:)

The models without batteries are twenty and a half oz for the prototype and twenty and three quarters for the new one. The batteries will push them to twenty five:wave:

[PipesCS]

Getting it ready for the final photos

Managed to get both into flying trim today and am just going over a few details.

[PipesCS]

Well this is done and its time to get back to the covering on the Model Y Gee Bee.

Once again if anyone whants a free copy of the plans drop me a line and I will send a PDF copy that you can have printed at your local Kinkos

The short kit is also available from John Valentine at Top Notch Products out of Tenn.

[PipesCS]

Well today was overcast and not a good day for photos but a good day to fly a first flight due to no wind and not scorching hot.

I finally get to say "It flew right off the building board.":)

Increasing the dehidral seems to have made it a little better at slow speeds

The longer nose with the motor being more forward helped with the CG placement.

I would say I was completely done but need to make a few changes to the parts cut order that CPC has recommended having started his PT-19

The really clear sunny shot is the Prototype flying just before I recovered the wing.

The photo of the two stacked on top of each other is why I like this size model. I flew both of them at lunch today and still went back to work.:(

[PipesCS]

Talking with a fellow modelers I pulled out the drawings and moded it them more time. The wing leading and trailing edges are now part of the laser cut short kit. John has added in the sheet stock and a few more items for the fuselage build.

Very quickly John is taking it from a short kit to the full blown thing.

Here are some photos of the proof model. (I now own four) It shows the aileron servos being moved to the outer wing instead of in the fuselage and the tabbed and slotted leading and trailing edges. Also shown is the vertical grain shear webbing that is also now part of the laser cut kit. They droped right in place between the spars. Total parts in the short kit now are at over 190.

The panel is ready to sand and shape the leading and trailing edge along with the wingtip.

Total time to build the wing panel was less than 45 min.

[Ballie]

Hi there from South Africa - I recentlysaw a member at my flying club with a "Spacewalker" built from a kit and wondered what it had originated from - it looks remarkably like the Fairchild PT-19.
I am also interested in e-flight and have built a 50" "Bubbles" which flies like a dream.
Please could I have a copy of your PDF plans for the PT-19 as I am very keen to build one from scratch.

[PipesCS]

Send me a private message with an E mail address and I will send you plans to the PT-19 and the Gee Bee Model D Sportster also covered in this forum

Charlie

[Ballie]

Thanks for the quick reply - my email address is robtech@sai.co.za

Rob

[PipesCS]

Ballie

Not sure you received the plans in my E mail as I did not receive a response.

Did you get them?

[jimamos]

Charlie,

Just a thought, as a scratch builder he might appreciate the earlier stick built version of the plans.

Jim

[PipesCS]

Digging in my old files I have found a copy of the stick built plans.

They are also available to anyone who whishes to scratch build.

If you send me an address through the Private Message I will be glad to send you both versions. One thing about the later version is the nose is a little longer to help with the balance using the lighter electric motors.

[PipesCS]

Having not flown in ages I managed to get the PT-19 dusted off and flew at a friends house. I am trying some 19 dollar LIpos from China. So far they are putting out ok. Of course they are rated at 20C and I am pulling around 5C so you would expect them to stay cool

Not doing too much with the PT-19 design and I can say it is now finalized at revision M.

It still is the best flying electric I have done to date.

[PipesCS]

I will mention a builder in South Africa who has taken the plans and scaled them up to a 60 in gas model. He plans to power it with a .46 and as the photo shows is "D" Boxing the leading edge to stiffen up the wing

True model builders can never leave it alone and build it as drawn.

I took Bob's gas model and converted the plans to make it electric. Now it is being converted back.

You gotta love the hobby.

[Ballie]

As I recently had my Stick 40 go AWOL due to a faulty switch and I don't want the same thing happening to my PT-19 when it is completed, so after searching around and not finding much on the net I am now using a wireless door chime which has a range of 100 meters and runs off 5 volts - same as radio receiver. Only mod is to change the heavy speaker for the largest piezo I could find - weighs next to nothing. All you have to do is push the transmitter button and listen for the ring.
I have nearly completed the wings of the PT-19 and will post some pics when done.
HAPPY FLYING...........

[PipesCS]

You might find these helpful on the gas conversion.

Bob's original was a .10 gas version

The cowl is hollowed balsa blocks with a paper tube cut into the lower section to route the air out.

I was thinking you may want to power the door chime with a small battery of its own just in case you loose the plane to a bad cell or dead reciever pack.

Do you guys fly on 72 Meg? In Japan years ago they were on 40

[Ballie]

Thanx for the pics of Bob's original, it will certainly help when I come to the engine location and cooling. In answer to your other question in South Africa we use 35Mhz and 2.4Ghz. You can view my clubs blog (VRMC) on http://196.211.8.196, we operate from a disused quarry with a lake (been in there !!) and very beautiful surroundings, unusual as it is in the middle of a city with about 3million people.

[Ballie]

Wings and tailplane section ready for covering

[Gary Rosa]

Your construction photos and comments are absolutely great. They would be awsome on CD so that they coul;d be referenced while building (my garage computer is not connected to the internet. It could be an opportunity for a "modeler for proft". That with the short kit and plans would be awsome. I am ordering the Gee Bee from John and would like to explore building it glo powered. Will know better when I get te kit and plans. Any tips? keep at it there are those of us wo look forward to PipesCS's next project.

[PipesCS]

If building it gas you will not need more than a .10 as this is what Bob's orginal had.

send me a PM on this site with you email and I will send you a build along and a article draft I did on it (Never Published)

[PipesCS]

I would recommend staying away from the "Modeler for Profit" arena as it is the dark side of the force and will destroy a good hobby for you.

Send you email and I will also send you the plans in PDF to look at in advance

[PipesCS]

Just recieved these two mails from Rob in South Africa.

Hi Charlie,
I suppose you thought I had given up on the PT-19 project !! It has just taken a lot longer than anticipated and I have had a lot of trouble trying getting an ASP .46 motor to run inverted. I eventually took it out and put in my Thunder Tiger .46 which runs like a dream. I also had to adjust the position of the fuel tank a few times but it seems sorted now.I just wanted to thank you for the plans and the pics you sent me, they have helped a lot.
I have attached the latest series of pics (which I will leave you to post on the blog) and as you can imagine I am very chuffed with the results !!


It has been in the air twice now and I am having to reduce the sensitivity of the airelons, but otherwise flies like a dream......
I have just received a 900kv Turnigy outrunner from Hong Kong
(www.hobbyking.com) which is the equivalent of an AXi2826 and might try that one day.
Prices from Hong Kong unbelievable as far as I am concerned - about a third of the price I would pay in South Africa and that is with 7 day registered mail, and taxes - well worth it.
Hope the knee op is coming on, have a friend who is having both done early next year and will be man down for 12 weeks !!

Regards
Rob


I still have the plans for anyone that wants to use them. Drop me an email and I will send them out.

[vmslehtinen]

Hi,

I am interest of building this model. I did sent a pm to Charlie about week ago, but he havent replied. Does anyone know is he still hanging around here? If not, does anyone else have both (stick fuselage version and newest version) plans available for personal use?

Thanks,

Ville

[PipesCS]

Sent off the plans. Hope they work out for you.

I am still out here but doing little to no modeling. New Knee was put in and then my job is driving me crazy.

Trying to do a little biking this year for the knee and bloodpressure.

Anyone wanting the plans send me a PM You might also post here to send me an email as I dont always check this site.