BatWing - Scratch Build - Flight Video and Plans

by LetsFlyRC | December 23, 2013 | (5) Posted in Projects

I am Shawn Morrison, from Orlando, FL and I have been into RC helicopters and quad-copters for the past 10 years. I followed RC Explorer, built David's tri-copter, and had some fun with that too. I got into the hobby because I wanted to film Pro Wakeboarders from the air with a helicopter.  I had some bad experiences with expensive crashes that delayed my interest, but over time, as technology got better, I kept trying.  I finally succeded in my desire to film from the air, and I, somehow ran across FliteTest.com.  

At first, I just looked up any multi-rotor videos I could find, because I wasn't interested in planes at the time. But, after watching several of their very entertaining videos, I started watching plane videos also. Once they came out with the Disney Planes characters, I was hooked, and for the past 6 months I have been perfecting my building and flying skills. Here is my own creation, inspired by FliteTest and crispy, from http://foamconceptjets.yolasite.com, with similar building techniques from the flitetest f-22. It was a miracle that It flew, because, I just got lucky, but It flies so great. It is extremely fast, and has very similar flight style as the f-22.

The only flaw in the design so far, that I have seen, is the small surface area between where all of the electronics mount, and the rest of the plane.  I tried to reinforce it with tongue depressers, but it still flexes a little.  But, even with that flexing, it still flys awesome and it is so easy to build.  Any helpful tips would be greatly appreciated.  

I was going to make a build video, but the build is almost exactly like the f-22 that I will link below.

I didn't include the angles in the plans for the winglets, because I just kinda played around with different angles, till I got the one I liked.  You can cut out a triangle to your desired angle.

The bottom vertical stabilizers were just lined up about a tongue depresser width from the prop slot.

The ailerons were cut, by lining up a ruler across the two arches in the tail.

I used the ft elements firewall to mount the motor.

I have no idea where the balance point is, I just got lucky mounting all of the electronics inside the front area.

I cut two lines in the front area to access the battery, and made a score line in the front to fold it up.

I hope you like it.  This is definately my most fun plane to fly right now.

 

 

 

Electronics:

 

Motor: FC 28-12   1534 kv hobby king motor

http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=42498

ESC: 18 amp hobby king plush

http://hobbyking.com/hobbyking/store/__30683__TURNIGY_Plush_18amp_Speed_Controller_US_Warehouse_.html

Prop: 8X6 APC style pusher prop from my local hobby shop

Battery: 1300mah 20C 3s lipo

http://hobbyking.com/hobbyking/store/__9272__Turnigy_1300mAh_3S_20C_Lipo_Pack.html

Servos: 9 gram hobby king

http://hobbyking.com/hobbyking/store/__22928__Turnigy_TG9e_9g_1_5kg_0_10sec_Eco_Micro_Servo_USA_Warehouse_.html

 

 

 

 

Plans:

BatWing - Adobe Illustrator Plans

BatWing - PDF Plans

 

Although, this plane flew very well, I am working to improve it.  Working on the Bat 2.0.

It will have the tongue depressers sandwiched between two pieces of foam board.  I haven't flown it yet.

- Find this article & others like it at www.FliteTest.com -

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COMMENTS

LetsFlyRC on January 3, 2014
Thank you guys for the suggestions. I was thinking about moving the motor back a little. I don't know how that will affect the cg. The rounded prop slot also sounds like a winner. I just made a new friend with a laser cutter, so it will be much easier to experiment quickly. I'd like to eliminate the tongue depressors. I wanted to make the build as easy as possible. My sandwiched tongue depressor idea was less than successful. It flew, but was worse than bat 1.0.
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alibopo on January 2, 2014
Very nice scratch build. I see the problem with the narrow join from motor/battery/receiver pod to the rest of the fuselage. If it's flexing now, in time the foam will degenerate and a crack will form, and very soon after that..... !!! One way to combat crack formation is to get rid of sharp internal corners. If you had rounded the ends of the prop slot that would help. Sharp corners like that in high stress areas concentrate the forces and 'invite' cracks to form. Some other ideas you might consider in version II - how about a higher revving motor? This would use a smaller prop and reduce the width of the prop slot, giving more material around the narrow bridge that's flexing. Even a very small shift backward of the prop slot/position would significantly increase the area of material in that join (as simple as a few spacing washers on the prop shaft?), or a modification (fudging) of the bat profile from the wing to 'bat head' so that the internal curve finishes a little closer to the nose - anything to increase the width/depth of material in this area. As a retrofit to the existing model you could laminate with balsa - creating a balsa-foam-balsa sandwich over the weak area - extending the balsa out into larger, more stable areas of foam. (Finish the balsa too abruptly and you just create another 'edge' for the forces to gather at.) I feel this stress concentration could still be a problem if you rely on the tongue depressors. Another possibility is to double/triple laminate the foam in this whole weak area. If the edges of the lamination panels are bevelled you'd hardly notice they were there after the model was painted. Great flying model though - looking forward to seeing the Mk II version.
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Chucky777 on January 2, 2014
I also think if you move the servos back to the more meaty part of the foam. it would help with the flex in the front.
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rezq911 on January 2, 2014
As stated in the comment above, reshaping the area where the bat head meets the wings would probably help alot. Higher KV motor, smaller prop, smaller prop slot: yes, yes, and yes.

My two cents: Put a KFm2 airfoil on the wing which will give more strength and lift.
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jobobcowman on January 28, 2016
how did you cut those curves? Ive yet to find a good way to do it without mauling up my foam
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amcknight31 on February 4, 2016
I have found that if you use a really sharp knife you can cut it without killing the foam.
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amcknight31 on February 4, 2016
This is really cool! I would love to see a build log!
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BatWing - Scratch Build - Flight Video and Plans