I have searched up and down the different forums and have yet to find a buid thread for an EDF version of Steve Shumate's T-38 / F-5. I got the kit for the pusher version of the F-5 from 6mmflyrc.com and absolutely loved flying this jet. I posted some pices here http://www.rcgroups.com/forums/attac...hmentid=797229

I have been itching to start an EDF version of the plane, and since I'm still relatively new to "scratch builds" I hope to have some feedback from more experienced builders.

Steve was of great help with some suggestions for the power setup of the pusher version (Mega 16/15/3, CC 35A ESC, TP2100 3S 1P, 6X4 APC).

My EDF Power setup is as follows:

Wemotec Minifan 480
HET Typhoon 2T
SPT 60A ESC
TP 2100 3S (may run two parallel)

My thoughts to start. After doing a lot of reading in different forums, especially the Bandit forum (there are a lot of great minds there), I found the minifan has an FSA of about 4.5" sq'd. That means that I would need just over 2.2" sq per inlet and will also try to achieve between 90 - 100 % exhaust, although I've heard that 80% will yield better speed performance, but for this build I think I'd rather have more thrust.

Even thought I wanted this to be somewhat of a pioneering project, I'm not out to reinvent the wheel by any means. I'll use as much tested knowledge as I can, giving full credit where it's due of course. For the EDF build, I thought I'd use as much of Steve's original plans as possible and modify only where required while still trying to keep as much of a scale look as possible. Here's where I may be way off, but after doing some meassuring, I thought that using the same inlets I would be just about 100% FSA. I would however have to increase the width of the fuselage quite a bit in order to fit the fan.

I have included some pictures of my progress so far. I would love to hear your comments, suggestions, and or critisism. Fire away

Diego

Hi Diego,
Sounds like a great project, good luck with it. I was just wondering if you had considered slightly enlarging the plans to fit the fan and then shrinking the inlet size down to match the FSA? You'd benefit from not having to modify the plans except in the area of the inlets and the T-38/F-5 has small inlets anyway. Just a thought.

Dan Eaton

Dan

I actually did think about that, and there's a 120% version out there, but even that was not going to be nearly big enough to fit the Minifan. I realized that if I were to enlarge the entire plane to fit the fan, I would end up with something so big that would be inefficient with the power set up. That's why I opted to just enlarge that area of the fuselage and try to make it look somewhat decent. Since this is my first "trial" I'll see what the finished plane looks like and learn from it. As it is right now I'm guessing that maybe doing the 120% version wouldn't have been a bad idea after all since the mods would be less obvious, but I already had a set of printed plans so what the heck .

BTW, I have to commend you on the F-16 build. I've read through some of your build posts and that plane looks amazing! Great work.

Diego

Question:

I've started making the plug for the intakes. I've had some experience with FG, but I'm still trying to figure out how I'm going to cover the sharp angles where the two inlets come together (at the fork). Any suggestions?

I can get creative and pull it off, but if someone knows of an effective way to do it, a tip would be much appreciated

I've started what I think is one of the crytical aspects of this build, the duct. I plan to carve a plug out of a block of foam, sand it, glass it, and then break-up and disolve the foam once the glassing cures. I got this idea from nopistons96 - F-18 build thread http://www.rcgroups.com/forums/showthread.php?t=515213

I have decided to go in a different direction with the ducting. I spent too much time cutting and sanding a plug for the fiberglass duct, but in the end I wasn't really happy with the results. I also realized that making a glassed duct system would take quite a bit longer and add a considerable amount of weight to the plane.

I have decided to go with a much simpler duct system using the existing surface areas, a styrofoam cup for the transition into the fan, and 3mm depron for the inside front ducts. This is a lot easier and much lighter.

I got the idea to use a cup from "Power" in his "New Wave Nano" build. I bent the corners of the cup using boiling water and being very gentle. I actually put the cup in for about 30-45 seconds and would then pull it out and bend gently. A better method might be to use water that can be tolerated with thick rubber gloves and work with the cup submerged.

Now I will need to mount the motor on the fan. I need to decide whether I'm going to use bullet connectors or wire the motor straight to the ESC.

OK. I've finally got the duct system installed . I decided to go straight from the motor to the ESC and skip the bullet connector as I don't anticippate having to go in to remove either.

Now the rest of the plane should be relatively simple to assemble close to the original plans. I also plan to hide the aileron servos inside the fuselage.

Very, Very nice build, I can't wait to hear about how this works out! Way to go, EDF's are so cool and it'll be really neat to see how your flies, I haven't heard of a single person doing the EDF conversion for any of Steve's pusher jets, except for the F-14 which someone did up with a double microfan set-up..... that one flew very well!

Anyway, I can't wait to see the contiued progress of this jet, way to go and have fun!

-Matt

Thanks Matt:

I really enjoyed the pusher version of this jet so I am also very interested in seeing how this will perform. I'll keep posting pictures and video as I move along.

Diego

im going to be starting on a edf f-20 by steve shumate and DCOBRA...110% should be a easy EDF conversion. your F-5 is looking sweet! you live in provo huh? i lived there for a while with my best friend after i got back from argentina...lots of sweet flying spots in provo, and nice wind conditions most of the time too...too bad i didnt have any of my planes with me then!

I finally cut and put the wings on. This was a tricky step because I decided to install the servos internally. I have also installed the aileron linkages so that they'll be hidden. I will cover the top of the wings with 3mm depron to cover up the carbon spar etc.

hey, where is that canopy from???? i need one for my f-20 edf build!!!
heres the link...

http://www.rcgroups.com/forums/showt...25#post5758708

by the way, its looking great!!!!!

im very intersted to see how it flys because my f-20 will be very similar in flight performance.

Brent,

Thanks for the comments. I actually bought the canopy with a kit for the F-5 Tiger II from www.6mmflyrc.com. It's one of the few pieces that survived the crash . Good luck on your build also. I'll have to check in and see how it goes.

thats what i figured...i'll have to give those guys a call!! thanks.