How about a speed contest? - Page 4 - RC Groups
Thread Tools
Aug 02, 2012, 06:04 PM
Registered User
sorry doin't see what you mean Extending the fuse to the end of nacelle is not that easy. Moving nacelle forward is also not possible, i think you will end up whit cg problems, to get it on THE spot it needs.
Sign up now
to remove ads between posts
Aug 03, 2012, 01:55 AM
Registered User
the down side of the fuse has a ellipsch shape. When it will be extended to the end, the backup side of the fuse will be to small to carry the wing. And cooling exit will be to small. Therefor i need to redesign the fuse when i will extend the back side of the fuse.

When moving the nacelle more forward. It will be to close to the CG.
This will limit you whit placing batteries in the fuse. When moving nacelle to the front, the batteries have to go to the back, to get the CG Right.

Thanks for your suggestion. But they are only for the looks, not for functionallity.
When making a speed plane, the nice look is the last you are thinking of. Functionallity is the one of the first to look at
Aug 03, 2012, 07:35 AM
Registered User


extended fuse
Aug 03, 2012, 03:56 PM
Registered User

box fuse

just to put this out ther I think lot less drag
Aug 03, 2012, 04:09 PM
Registered User
Almost ready for foam build.
Do you keep those wings that flat? Or is just because it was easy to draw?
Aug 03, 2012, 06:00 PM
Registered User
ALL the one's i build have flat wing's with 25% to 50% kf on top
Aug 04, 2012, 03:18 PM
Registered User

wing temp

cut wing temp 30'' may curl tip's up may be better than V tail I think we got winner hear now Iam all geked
Aug 04, 2012, 06:16 PM
Registered User

foam cut

cut wing & fuse had fan set up 55mm 3500kv 1300ma battery wing may be a little fat good for low wing loading
Aug 04, 2012, 06:22 PM
Registered User


Last edited by space 1; Aug 05, 2012 at 05:43 AM. Reason: oops
Aug 05, 2012, 06:24 AM
Registered User

v tail jet

found this
Jetiger With Newspaper (0 min 11 sec)
Aug 06, 2012, 02:07 PM
Registered User

Help help help

Hi guys,

I need some help. I got stuck whit the design.
I went whit the tips from Erik. But i can't get a design out of it, which looks like its ok. The design i now have just looks like a whale. And what i know, whales are not fast.

How did i came to this design?!
I copied the wings of my earlier design, they look ok i think.
But getting the fan in de right thrustline (wing middle). I moved this down. To get a straight flow, i made a fuse like a mig15. But everything of the fuse which is not needed is removed. The top view looks very widht, this is done for placing the batteries (in my case 3s 5000mAh left and right of the fan). Why i didn't make de widht smaller? maybe i want to fly whit more than 6S in the future. Than mAh will be lower, so i get space for putting in 2 cells more.
The side view is lower, this is done, because none of the batteries will be on top or bottom of the fan.

I don't like the design. But got stuck whit it.
Maybe you guys can help a little what to do, so i come back on the right line whit the design.

P.s. sorry not in 3d design. For me it is easier to draw in 2D. When that looks right, than i will make a 3d design. I am not that good whit 3D drawing.

Aug 06, 2012, 02:08 PM
Registered User
oh yah, forgot to say. Don't look at those booms for the tail. I know they are to small. But first need to get the design right, than those booms will be changed.

Some details:
Fuse length: 77cm (whitout booms)
Fuse widht: 18cm

I already thought about making a 90mm pyranha. I have the original 70mm pyranha. Flies that nice, that i already thought about making the some design, but than bigger. Never had a better flying 70mm jet than the pyranha.
Even my uriah copy (from Erik copied), doesn't fly that good. But that was because of me. I didn't build the wing straight and therefor it flies terrible.
Aug 06, 2012, 04:39 PM
My project: FAIREY DELTA 1
Erik v. Schaik's Avatar
You shouldn't scale up the Pyranha. The 90mm units don't produce the high efflux 70mm fans do on low power plus a bigger model appears to be slower IMO.If you want a great 90mm edf you'd fancy the EB a lot which saves you several years of moulding.

You'll be amazed how sleek your fuse is with a small F16 shaped cockpit on it. 2D pictures don't look like the real thing. I even printed some planes to real size to see the real dimensions and still it is very hard to see the real shape which isn't boxy at all thus much sleeker.
yeah the shape of the fuse looks a bit boring now and I bet it wouldn't be an improvement on the EJF Bob-e-Cat (which I wanted to order a kit last year but with no luck).

You need to think much more out of the box to make a real difference. First you need to make up your mind what you like in a design IN GENERAL and what not and deal with those issues.For instance:the Pyranha concept has a very weak tail section which could cause flutter at high speeds. For me the biggest challenge is to minimize risk of flutter at 200+mph which seems to be a neglected detail on many projects.

Don't get discouraged on designing a high speed edf. The Uriah-BU took me 4 years to complete. It started with the design contest winner Tsunami and was mixed with the good design of the Pyranha and Blade2. The next project which is in my head now wil have additional mix of at least 2 more planes along with the Uriah-BU.

Design a plane you like yourself and don't catch up too many inputs of others because history shows you would end up with a plane similar like a sniper.

good luck!
Aug 06, 2012, 04:46 PM
My project: FAIREY DELTA 1
Erik v. Schaik's Avatar
forgot to mention a midwing is a weak base to start with. Very hard to build as well.
You need a one piece wing as a base, place the fan where needed and continue along those parts. make a list what hardware you need and what not and explain why you need those specific parts. if you cannot give a convenient answer you need to find a good answer and start trimming your outlines again. This will take several cycles.

Many details are of personal preference. As you already noticed it is very hard to make a single purpose plane.

good luck,
Aug 10, 2012, 07:19 PM
Registered User
f16 build is ready for a speed test tomorrow or Sunday. Should move pretty quick.

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion How do you guys feel about Nitroplanes? (The company) rckatz Nitro Planes 36 Nov 29, 2012 05:33 PM
Question Question about flying wing CG and how it might be affected by adding a fuse daronj Foamies (Scratchbuilt) 2 Jul 01, 2012 02:10 PM
Contest Hobby Lobby Lynx Speed Contest!!!! CONTINUED NEW Current top speed is 139.6 mph! dpowellmeii Pusher Prop Jet Models 7 May 21, 2012 12:52 PM
Rave How about a Tiger Moth gliding contest? swooper GWS (Grand Wing Servo) 3 Nov 08, 2003 04:09 PM