Meet my new "friend"

[Dave Robelen]

Hi Folks,
I have been at it again. This time I decided to take another look at what could be done with a lightweight pattern model. The result I call the Pattern Babe. The wingspan is 28.5", while the area is 192 sq. in. With a weight of 5.7 oz. the loading is a bit over 4 oz./ft. sq.
The airfoil is a NACA 0018 symetrical, both root and tip. I tried a new construction method on the LE, and molded a sheet of 1/32" balsa on a foam form, and then glued this to the rib noses-works great!
Power is a GWS EDF motor running in the "E" gearbox @10.7-1, and this is fed from an 8 cell 120 mah ni-cd. The prop is a 9-6 with "parabolic" pitch.
Controls are R4P receiver, Pixie light ESC, 2X HS-50 servos. Aileron and elevator at present, maybe rudder later.
The first flights were made from ice crusted snow, and right from the start it is proving to be a delight. Slower and smoother than my Flap Jack, it still rolls and pitches plenty quick for maneuvers, but is smoother in the process.
Regards, Dave

[Dave Robelen]

Another angle

[Dave Robelen]

One more angle

[Dave Robelen]

Check that space

[Dave Robelen]

Finally, the power room

[bmutlugil]

Hello Dave,

Another good looking model.. I suppose it flies as good as it looks..

What is the clear covering material on the wings? and what about using a 3-cell Kokam 145 battery, will this be too much voltage?

Regards,

Bulent

[Dave Robelen]

Hello Bulent,
The clear material is 4 um Mylar from Dave Lewis. The difficulty with using Li-Poly cells with this motor is the high current levels. At the 9.6 volts, the static current is about 2.5A. Two Li-Poly cells are not quite enough power, and three draw too much current. It may be possible by adjusting the propeller smaller to operate safely with 3 Li-Poly cells, maybe I will get to that. My main focus to date has been on the airframe development, I should also spend more time on propulsion.
Regards, Dave

[Fwilly]

Do you think this plane will end up being an rc microflight plan? If so then I will have to renew my subscription. That is one nice looking airplane.

[fly_joy]

beautiful

[Dave Robelen]

Hi Fwilly,
I'm gonna give it a shot. With all balsa construction, and no bad habits, it ought to appeal to the folks at the office. I really won't know their decision for awhile, but one of the staff will be reading this thread, so maybe you will influence them.
Regards, Dave

[Mike Taylor]

Plans, Please! Publish or perish! Even a half size plan would be perfect (said the RFFS nut...);)

[SnoJetter]

Dave, how 'bout plan availability for those of us who aren't microflight subscribers?

Kyle Sands <>< Huntley, MN

[2NG]

Hello Dave's new Friend:)

WOW.. Dave, that is a fine looking bird. What entry level will this new bird of yours be in. Beginner aileron, or Moderate to expert Pattern plane.

You got me interested, because it uses Li-Poly cells, and I'm just getting into using those batteries. My batch of cells just arrived.

***but one of the staff will be reading this thread, so maybe you will influence them. ***

I hope they will grant you, your wish, because I would love to get my fingers glued, with one of these:)

More power to you,

Antonio

[Dave Robelen]

Hi Kyle,
You do not have to be a subscriber to Microflight to buy the plans. Once it becomes available, it will be sold throught the RC Store, the online plans service. They will get the material from me fairly soon, when it is published would be their call.
Hi Antonio, I would put the aerobatic capability in the advanced class. It is easy to fly cruising around, but there is plenty of control power for rolling and pitching, and the symetrical wing doesn't care which way you go. I am committed to having a small field aerobat that is not limited in the performance of basic maneuvers. Notice that I neglected 3D, because this all too often leads to a "touchy" model in the smaller sizes.
Cheers, Dave

[2NG]

Thanks for the response Dave, I'm getting into 3D flying, slowing down in Pylon Racing, but still racing.

Now 3D:D

***I am committed to having a small field aerobat***

Actually, I'm looking for a plane, that can challenge the Mini Laser, after looking at your pic. The wings grabbed me. I love it, somewhat similar to an Accord.

Does this new bird has room for upgrades? GWS type, but bigger for more thrust.


--- And one very important question. What's the word, is she going to be printed in the rc microflight plan? .. If so ( I know it would, because all your models do) how long does it usually take?

[Dave Robelen]

Hi Antonio,
Yes, you power hungry rascal, there is roon to stuff more power under the hood. As far as the 3D stuff goes, it is mainly a mettar of moving the CG aft, and making sure the elevator has ample throw.
The publication schedule? That I cannot guess, except that most of my other work has gone pretty quikly. A few months or so would be typical.
Regards, Dave

[2NG]

***A few months or so would be typical. ***

Cool, Cool..... I would love to make this baby prop. hang with those mini AC brushless. If you don't mind, Dave:D, that settles it, this will be my next project, as will, as my second sractch build airplane.

****Yes, you power hungry rascal, there is room to stuff more power under the hood. ***

I can't help it, I love high speed motors:D Thank you DAVE, just as long, as there is ampule room (Ear to Ear :D )

Fwilly, Are you ready for this plane?

yours,
Antonio

[fly_joy]

This has made it an easier decision for me to renew my subscription. Another great Robelen plan!

[Fwilly]

2NG,
If you mean can I fly it then yes, I'm pretty sure I can. I have a MM Mini Flash right now and most of the time I fly it alright but I when I crash it I usually crash it good. right now it has some gaps in the fuse where I didn't recover all the pieces after an almost fatal crash. I have the bad habit of flying all my planes in close and low. Before my Mini Flash the last three planes I had were under 16" wingspan and 3.5oz and it wasn't a problem with them, but I get into trouble doing that with the bigger Mini Flash. It doesn't look like a problem for Dave's new plane though. As soon as I break my bad habbit I think I will stop crashing my mini flash so bad.

[2NG]

Fwilly,

You took me by surprise with your scratch built, I know you can fly this, this is in your neighborhood (Scratch Building).

***I think I will stop crashing my mini flash so bad.***

Don't you worry Fwilly, your still young. Time is on your side, you will do great, just keep those thumbs under control.

MM mini flash EH? That's the only plane that I don't have:( but since Dave's plane caught my attention, this plane will be, I think the answer to the Mini Flash, and Mini Laser 3D:D

***This has made it an easier decision for me to renew my subscription. Another great Robelen plan!***

Fly_joy,

Got you too? I know how it feels, it was love at first sight for me.

*** Guys, let give this plane and Dave Robellen a push towards getting this plane out there:)

[468/f]

Hi Dave,

I like your new friend too. Snappy lines.

Could you say a little more about the leading edge and how things went together. Is the foam still in the wing? Maybe post some pics that show how you shaped the LE. Interesting idea.

One more thing, could you post a shot of the power plant from the top side looking down on it. Is this motor mounted on a stick?

I like the clear covering. That is neat stuff. How is it to use?

Thanks so Much,

Roger

[Dave Robelen]

Hello Roger,
Thanks for the kind words. About that Leading edge. This is a copy of the system that Top Flite used on the Taurus design back in the sixties.
I first made a form from the stiff type foam (not beaded) that was the shape of the leading edge. This was done by pinning an airfoil template to each end of a foam sheet 1" thick, and then carving & sanding the foam until it looked like a wing leading edge with about 1" extending toward the rear of the airfoil. I then cut two strips of 1/32" balsa a bit wider than the finished part, soaked them in water, and when flexible wrapped them around the form using an Ace bandage for pressure. When these were dry, I had two "Taco shells" of 1/32" balsa that were pre-formed to the LE radius.
The wing was assembled by pinning the top spar to the board, adding the ribs & webbing, the TE and the bottom spar. I then glued these shells to the front of the ribs which had been undercut to match the 1/32" thickness. Result? a very light, accurate LE that is stiff and aerodynamically strong, but will be easy to damage in a crash. I hope that answered the question-the foam is still on the bench.
If I took a picture straight from the top, all you would see is the heatsink showing between the cowl sides. The power unit is the GWS E verion of the IPS drive (just like a Litestick with higher ratio). There is a length of hardwood stick mounted in the front bulkhead with extra wood bracing on the back of the bulkhead, and the drive is simply pushed into place. I use a small retainer pin through the plastic drive and stick to keep the drive in place.
The covering is very pleasant to work with. I use a paint on adhesive called Coverite Film Formula that is painted around all of the edges where you want the covering to stick. You then iron on the Mylar film in the usual way. Since this is the same plastic as used in Monokote, it shrinks up very nicely with a hot iron.
All of the color is auto touchup spray can paint misted onto the bare wood from the spray can. The complete color job added 5 grams to the model. The film plus color added 4 grams to the wing. Although the wood is not moisture protected, it does give a bright model when flying, which can be a big help to these tired old eyes :)
Take care, Dave

[468/f]

Hi Dave,

Thanks for the details. That is a great way to shape balsa. I would almost think it might be stronger that you think. That is a fascinating method.

OK on the motor and it's mount.

I think you have a neat plane. Add it to "the LIST!" ;)

Thanks Again,

Roger

[2NG]

Hello Dave,

I will be forwarding this thread to lot's of people, specially Edogflight is really interested in this plane, we are going for GWS set up and Li-Poly's... Glad I bought a new charger... Triton, great charger, SIMPLIER THAN THE ORBIT:D I don't need a degree to fool with it:p


RC,

Check back on my H.O.B P-51 thread:D Great news....:cool:

[Dave Robelen]

Hi 2NG,
Boy, did I start something or what? Glad you like it.
Regards, Dave

[2NG]

****Boy, did I start something or what? Glad you like it. ****

Dave,

Honestly, we put this plane in the magnifying glass today. Not only me, that liked it. You where the subject at the field today. We love it... I'm going to another field tomorrow, and they too, want's to see the pic. of this plane as well, as it's spec's..............

This plane is a hottie, yes it is:) everything looks nice, the rudder area is big enough to aid in what we are looking for. This will be our answer to the Micro Cap, yet, it has the right specs. As they say, to make this plane Hover and prop. hang.....

Your welcome Dave:)

Yours,
Antonio

[genebond]

Looks like a winner, there, Dave. Glad to hear it will be published. Sounds like a 'must have' for the list.

BTW, are you getting acceptable life w/ 8 NiCds on the EDF motor? Lots of power, there! 2.5A shouldn't be too bad, but at 9.6V, that's 24W! Wow!

Who's prop is that? Looks (and sounds) different...

[Dave Robelen]

Hello Gene,
Thanks for the nice words. Actually, I am very pleased with the life of the EDF motor in this application. Typically, it is not even warm at the end of a flight. Factors that influence this are A- The current at cruise speed drops to 1.4A. B- I only use full throttle in short bursts for specific maneuvers.
The prop is one of my home brew blades. I am sort of surprised that you are the first to notice. A GWS 9-7 does a fine job as well.
Regards, Dave

[Don Cooper]

Dave,

Where is the battery mounted? I always have trouble squeezing the battery into my slim-bodied planes and end up hanging it off the bottom, which sort of defeats my reason for making the body slim.

[Dave Robelen]

Hi Don,
The cells I am using are kind if slim, A Sanyo 120 mah ni-cd. I made up a pack of two layers of 4 cells side by side. This pack fit nicely into the area between the motor bulkhed and the the wing spar. There is also room in there for the 1020 mah Li-Poly's.
Regards, Dave

[Don Cooper]

Dave,

Thanks for the quick response. Looks like I need some LiPoly's.

[yeeehaw]

I lve the clear covering can you get it at your lhs or do you have to order it.

[Dave Robelen]

Hi,
I doubt a LHS would carry that item. You can find it at Dave Lewis's site www.homeffly.com as Westech clear mylar. The 5 um would be about the same as what I used. Give Dave a try, he is very responsive and helpful.
Regards, Dave

[2NG]

Dave,

How the friend doing, are we going to have a crack at her someday? (hehehehehehe..... That sounds bad..hehehehehe LOL:D )

Antonio

[Dave Robelen]

Hi Antonio,
The material is in the hands of the editors. Sadly, they do not tell me how they schedule material. Hang in there, and build a couple of dozen more models, it's coming.
Cheers, Dave

[2NG]

****The material is in the hands of the editors. Sadly, they do not tell me how they schedule material. Hang in there, and build a couple of dozen more models, it's coming.****

That's a good news, thanks Dave:) ooohhhhh, I'll be building.. My next question is. How do I stop? Or when do I stop?:D

[miraclesailor]

Dave:

While I was thinking about combining all the ideas that I have to making a small flyer and studying your planes and plans I came up with an idea to slightly(?) modify your Pattern Babe. Thought you might be interested in the way it looks with the mods. The idea is to make it elevons and rudder control. Total weight about 6oz. Folding wing for small case. I am thinking about using EPP leading edges backed with Bamboo sticks. It may save some repair work. I think that using a 3pack of LiPolys will give great performance, though at the expense of a motor or two due to the high voltage. I am trying to get propeller hanging performance. Hope you do not mind the mods. I will post the finished product when complete.

Later,
Dan

[Dave Robelen]

Hi Dan,
Boy, you sure are handy with the graphics package! That looks like a fun idea. My one real input would be to consider a different airfoil. My choice of the thick NACA 0018 is fine with the very light LE, but the EPP on such a thick wing would up the weight considerably. Meanwhile, in the field of tailless aerobatics, the Zagi 'foil, or the one used on the Scimitar series of flying wing planes would be very well suited to your plans. You might also have fun with the CG and my nose length, since these tailless machines balance very far forward. A nose stretch, maybe?
Have fun, Dave

[t-turley]

miraclesailor,

I like your idea! It looks like a baby Scimitar - that is, to someone who's old enough to have seen/flown one of the old Bill Evans designs.

I guess I'm showing my age. :rolleyes:

Tony Turley

[miraclesailor]

I finally found a picture of a Scimitar. I looked for a while. When I found it I realized how close my modification was to one of those. Thank you for the information on it. It is too bad that I had already cut the ribs for the NACA 0018 ribs when I read your reply. Well it is just a little more work to make more. It looks as though the Evans design uses more of a NACA 0012. He mentioned that it was a little heavy to fly when he converted one to an electric. I thought about some modifications to the wing and came up with about a modified NACA0015 with the maximum height of the rib moved to about 25% from 33%. This, I hope will allow me to fly slower and still be able to perform acrobatics. I do fly combat wing gliders and do not specifically like the way the Zagi flys. It seems to stall while still flying pretty fast. There are some other wings that stall a little slower but I was looking for a really slow stall rate. I will see what this can do. I am not using very much EPP for the wings leading edge. I thought that just about ½ inch on the front would keep me from catastrophe. This will not add too much weight. We shall see what we shall see.

Later,
Dan

I have attached a picture of the modifications to the ribs.

[Dave Robelen]

Hi Dan,
Sometimes it is hard to be really different eh? Bill Evas designed a kazillion variants of the Scimitar, including a tailess CAP 21. That rib rework lokks like you are headed in the right direction.
One thing about the Zagi stall. The wing is swept back, and that usually causes a lot of outward spanwise flow. Not good. The Evans wings, and the Pattern Babe stay clear of that trap. The only reccomendation for rearward sweep would seem to be a wiser CG envelop.
Take care, Dave

[yeeehaw]

I have been following this thread and your other threads, and I am very impressed:D . Great job. I was wandering is there any other alternitivs (sp) in GWS 1180 props. I wen't threw 2 props in the same day.

good luck and nice planes.
Matt

[Dave Robelen]

Hello Matt,
The APC props do a great job, and are sturdier. They measure the pitch different from GWS, so I usually go down 1" pitch to get a match. Example- 10-7 GWS= 10-6 APC
Regards, Dave

[yeeehaw]

thanks alot
I say again, Great plane

Matt