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Oct 09, 2008, 07:55 AM
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boopidoo's Avatar
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Build Log

The Shadow 200 Foam Project


I've wanted to build something from scratch making my own plans etc for some time now. It would be great if the finished a/c would resemble an UAV so a while back I thought of build something resembling the predator but I've moved on and have now my eyes set on the Shadow 200.

I plan on building the a/c in 1:4 scale mostly out of depron, even the wing profile which will be something new for me. The plans will be made in Inventor in which I have built a model to base the plans on.

EDIT: The first model will be in 1:3.5 scale.

I figure the Shadow 200 to be a more stable platform and also an easier build then a predator look-alike.

If my 1:4 scale works out ok, the plan is to make a 1:3 scale version with a FPV system. Check out the FPV-thread below:
https://www.rcgroups.com/forums/showthread.php?t=959846

Also, this will be a winter project and there may be a while between updates.

EDIT2: I've updated with PDF-plans.

IMPORTANT BUILD INFORMATION!
  • The wings need more structural support along their span since the carbon rod isn't enough. I've solved this by adding some depron support along the wing span from the tailboom and two sections out.
  • The wings may need better alignment with the fuselage, I've fixed this by using two short carbon rods sticking out from the leading edge of each wing just inside the walls of the fuselage.
Last edited by boopidoo; Aug 08, 2009 at 02:41 AM.
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Oct 09, 2008, 01:06 PM
Planes are cool ;)
Hughbert's Avatar
Awesome rendered model, mate Good luck with the build

Hugh
Oct 09, 2008, 02:22 PM
Build it again, Sam!
Harpye's Avatar
Designed for styrocut right !?!?!
Oct 09, 2008, 02:34 PM
Registered User
gromitvt10's Avatar
Awesome!! I just got back from a 7 month tour in Iraq flying those. Let me know if you need any info on it and i'd love to have an small R/c version, since i've already flown the big R/c version..lol Check out the last page in the Sept issue of Model Airplan News Magazine, you'll see me:-)

Kyle
Last edited by gromitvt10; Oct 09, 2008 at 02:42 PM.
Oct 10, 2008, 02:47 AM
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boopidoo's Avatar
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Thanks!

@Harpye I actually plan on making the model with 6mm and 3mm depron sheets. After the CAD-model is the correct dimensions I will use the solids (wing, fuselage and fins) and cut out 6mm-slices which will be the basis on the set on plans I'll make. The CAD-model is scalable in its main dimensions but dimensions such as sheet thickness, servos and engines are not. This way I can easily change between 1:3 and 1:4 without having to make a whole new model.


@gromitvt10 that is really great! I've made the model out of some three view sketches I found on an pdf-document but they aren't really accurate. What I need to make the model better is:
  • A good three view sketch (with dimensions if possible)
  • Some info on the wing profile
  • Location of centre of gravity and centre of lift?
  • Any pictures on the insides of the beauty
  • The manual? (I know I'm asking for a lot here )
  • Well... any pictures at all close up to see the details
Last edited by boopidoo; Oct 10, 2008 at 03:09 AM.
Oct 10, 2008, 04:31 AM
Build, fly, learn!
Hi,
I am working on a similar looking RC model with my friend Louis Fourdan. The differences are:
- the wing will be divided in three sections, with the two outer sections as control surfaces, with some dihedral.
- identical inverted V tail but no control surfaces.
- the motor will be mounted in a pod aligned with the wing TE.
It will be built with a mix of 3 and 6mm Depron, as lightweight as possible since one of the design objectives is to get something that flies very slowly and is very stable.
Oct 10, 2008, 08:53 AM
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boopidoo's Avatar
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@ADB2 please feel free to post images of your progress. It seems very interesting.
Nov 20, 2008, 09:04 AM
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boopidoo's Avatar
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I've continued the project on my spare time. I've made an almost complete model in 3D-CAD from which I can easily extract 2D-plans. Details such as battery and servo positions isn't in the model but I know where I want to put them:
  • The battery will be positioned in the front part of the fuselage, the exact position depends on the CG.
  • The aileron servos will be placed inside the wings in front of the ailerons.
  • The engine controller will be placed below the fuselage in the "red box".
  • The tail rudder servos will be placed inside the fuselage with flexible push-rods inside the spars.

I've also changed my mind about scale. I will probably make the model in 1:3.5 scale which will result in a wing span of aproximately 1.2m (~4ft). Would this be big enough to carry a FPV-system?

I'm not 100% sure about the engine mount or the way the balsa structure is made. This way with two fastenig screws above and below the engine might not be the best solution. Maybe a solution with four screws will be better?

Also I'm not sure how I will construct lightweight hollow spars (plastic or aluminium?). The aircraft must not be tail heavy.

High-res picture of multiview.gif
Last edited by boopidoo; Nov 20, 2008 at 11:30 AM.
Nov 26, 2008, 10:07 AM
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The design is almost finished. I know where the battery should go such as the reciever, ESC and servos etc and have also these modelled. The tail servos may have to be moved depending on how much the push-rods can be bent.

Carbon fiber tail booms are almost ordered. I'm choosing between 16,7x14,0mm or 15,2x12,5mm dimensions. To be scale I think I would have to go with an outside diameter of aproximately 17mm but I try to cut weight. As it is now I want to get the weight below 1kg and I'm closing the gap too quickly.

I've found nose (35mm) and main wheels (55mm).
http://www.hobbycity.com/hobbycity/s...idproduct=5648
http://www.hobbycity.com/hobbycity/s...idproduct=5623

See picture below for my idea of placing servos etc.
Nov 26, 2008, 05:35 PM
Registered User
Boo, Great project! I am in the process of resurecting an old swept wing build I did in '02 out of a 4' chuck glider called the Sky Rider http://www.acesim.com/rc/pw/pw.html The original idea was developed by a fella named Ken Hill. The swept wing was supposed to add stability since it was also a flat wing i.e. no diheidral. It was very stable but not too responsive to elevons and really needed ailerons. I didn't pursue it any further because it was so under powered with the brushed speed 400 of the day. I'm building another because the motors and batteries nowadays are so much more powerful I'm thinking that setup will really fly great. I was even thinking simple thrust vectoring on a stick type motor mount might be interesting. I used carbon fiber arrow shafts for the booms and coroplast for the tail feathers. cutting one side of the flute makes an instant hinge and they last a long time. The only thing I had a problem with was balance as the long boom and tail tends to make balancing on the CG a challenge so just a word of caution in your designing. I was surprised how much weight I had to stuff in the nose of that thing to get it balanced. I will watch with great interest as you develope your bird and I will post as I get all my stuff together!

Good Luck

Paul
Nov 27, 2008, 05:22 AM
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Thanks Paul! Your project is very interesting and I guess many of the problem areas with both projects are similar such as the aircrafts being rear heavy etc.

The weight with the long booms is an issue I know about and try to fix with my design. For instance I might go with 15,2mm booms instead of 16,7mm just to cut some weight, the 15,2mm are 10% lighter. And I think I'll make the tail surfaces as light as possible with the same design as the wings if possible instead of just using 2 or 3 layers of 6mm depron.

The end part of the tail booms will be made of some plastic mold, I'm not really sure how yet but I'll figure something out.

This design is supposed to fly without a FPV system and I don't even know if a such system will fit but it will probably make the CG-issue easier to handle since it only adds weight to the fuselage.

Another problem is the propeller area. I must use an 8" propeller to reduce the risk of it hitting the ground while landing (see pictures). But this makes the area kind of small. I don't know if it's enough?
Last edited by boopidoo; Nov 27, 2008 at 05:31 AM.
Nov 27, 2008, 08:43 AM
Registered User
Boo, I see your point. Unfortunately I have just started exploring this new era of electrics so I'm hopin some of the fellas on this forum that know their stuff will help out in the power department but I'm thinkin that a 8" prop with the right motor should do the job provided you build light enough. With a 4' wing you should be developing a lot of lift. I also see that your fuse extends forward pretty far which should give you some leeway in adjusting for CG. My original design was very stubby and that was a problem. My new version will provide for a longer nose. Your plans look good dude!
Nov 27, 2008, 09:12 AM
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I've started a sister thread to come in contact with the guys at the FPV-section which is located here:
https://www.rcgroups.com/forums/show...6#post11019705

Although this thread will be the build log. The other thread is for FPV related issues. I will model a FPV system however to make it fits the scale I choose before building.

Also, I don't know if the wing profile is optimal. If anyone knows the wing profile of the Shadow 200 I would be very happy. Or any other profile for that matter which would suit this model. As it is now I've made the profile from a three-view sketch of the Shadow 200 which probably isn't correct.
Dec 17, 2008, 01:42 AM
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Hi again!

Progress has been made although primarily in the FPV-area. I've included some pics from that other thread.

I'm now in the process of making plans which will be posted shortly. Please bear in mind that this is still in a prototype phase and I'm not convinced it will fly until it actually does.

I've included some pictures of a trial wing I made a while ago just to try out a new technique (for me) making a 100% depron wing. The wing I made had a span of 250mm and a chord of 125mm and weighed about 11g. I made this very quickly so the end result isn't very beautiful.

EDIT: Added plans in PDF.
Last edited by boopidoo; Jan 10, 2009 at 10:33 AM.
Jan 07, 2009, 03:54 PM
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kram242's Avatar
Great design work and really cool project thanks for sharing with us.
Mark


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