12.5" Span Brushless F-15 Experiment

[Lost In OC]

Out of shear boredom and a need for a liitle excitement I decided to build the smallest, fastest jet I could dream up. With the help of a new brushless motor (the short feigao 120) I'm going to attempt to build an extremely small f-15 eagle. I'v successfully built a bigger 22" f-15 in the past, using the bigger feigao motor in a pusher configuration. The new baby jet is gonna get the new bluebird 3.1g servos for direction, lightened bluebird Rx 2g, Sky Hooks speed controll 2.4g, 3 cell 240 mAh lipo battery, and feigao brushless motor 10g. With a 12.5" span, I hope to build a plane under 2 ounces out of 1/16 and 1/32 sheet balsa, and 3/32 square for the corners of the fuse. I won't expect to get much of a curvy fuse, but with some markers and clever shading the plane should look nice.......Time will tell. Oh, and I really think this thing is gonna move!!!!

Here's what I'v got so far......the wings are built up at a gram a piece. There's the 3 views I'm using that I got off of eduardos page of 3 views http://www.fortunecity.com/marina/manatee/272/

[HanksGB]

you're nuts......GeeBee, GeeBee, "Hey Chris do you think we should wait untill it's light out?"

[Lost In OC]

Hey, so what if it was dark outside, the geebee needed to ble flown....errrr....crashed. I think I'll wait for light on this one. I'm gonna have a hard enough time seein this little thing zoom bye at 50 mph!!!!

[PIV]

Im waiting to see it indoors at a velodrome, banked over hard racing some guy on a track bike!

[esb-help]

use guillow plans :D been there done that ;) feigao,3s1p kok-340's auw 4 1/8oz. around 65 mph :eek: good luck,let us know how it goes

[Ben_E]

You can find much better 3 views for the F-14 from Dryden Aircraft Graphics Collection:

http://www.dfrc.nasa.gov/Gallery/Graphics/F-15A/Small/EG-0031-01.gif

The images can be found here (http://www.dfrc.nasa.gov/Gallery/Graphics/F-15A/index.html)
If you download the EPS files you can scale them to the size you want without loosing quality - no fat lines ;)

Ben_E

[Lost In OC]

Just what I love about e-zone a wealth of info!!! Those are some sweet lookin jets, my hat is off. Whats the smallest jet you'v built? Is that the short gold feigao motor? Mine is about 3/4" long.

[esb-help]

Just what I love about e-zone a wealth of info!!! Those are some sweet lookin jets, my hat is off. Whats the smallest jet you'v built? Is that the short gold feigao motor? Mine is about 3/4" long.
the f-16 in the pic is the smallest,it was originally df with a edf-40,but the eflux was to small for any good thrust so all it would do is wallow around and barely keep its altitude,but it is airworthy,the feigao i used is the longer 12mm version,of the 2 the f-15 really rocked :D i even had a small cdr motor on it but it was too fast!!!!!!!!!!! the f-14 in bare bones in the pic is being built with functional swingwing :eek: heres a few more pics of differant stages in the building process of the lil birds

[esb-help]

these are the guillows build-n-show models

[esb-help]

and more ;)

[Lost In OC]

Looks great! I'm workin on getn more pics of my project

[Lost In OC]

Getin closer to completion! I finished framing up the fuse, I left the bottom open for ease of installing the electronics. I decided to go with full flyiing stabs so I used my tried and true meathod of using carbonfiber rods, plastic housing tubes, a thin disc of plastic to avoid binding, and snipped down fma servo horns glues to the carbon rod. "Dry" weight came out to 18g, lighter than I guestemated, yay!!! Like I said earlier, shes not the curviest F-15 around, but I think she turned out pretty good. Can't wait to install all the gear. I'm just waitn' for the esc to get shipped.

[HanksGB]

Chris
Lookin' good. keep this one in one pice until I get home please. I'd like to see it fly. Any idea of an AUW? the cap is finished and AUW is up to 5.5 oz.
I think she'll fly well.
good luck
Henry

[Lost In OC]

I think it's gonna be in the 2oz range. If 28g = 1oz and I'm at 18g right now.....lets see. radio equip is 9g, power including batt and esc is about 29g, and hardware will be about 3g....total estimated weight will be about 59g or 2.08oz. With my luck she'll be alot heavier.

[Lost In OC]

Radio installation begins today. I think I'll test glide her without the motor to find proper CG. My luck I'll f-up the hand launch and smash in the nose! Any body know how much current the shorter of the gold feigao motors draws????? I could only find info on geared applications. I'm just gonna use a gws 2.5 x 2 prop.

[Lost In OC]

Ok, everything but the motor is installed. I think I'm gonna have a tail heavy prob. Oh well, I can fix that with more mAh. Everything went in smoothly, I'm not too impressed with the centering ability of the bluebird 3.1 servos but I guess I'll have to make due until another plane in the hanger decides to give up it's servos. As picured the Eagle tips the scales at 52g, with the motor installed I'm guessing 65g....2.29oz....not too shabby

[nopistons96]

Nice build OC. When's the maiden? get video, please.

[Lost In OC]

The maiden should be tomorrow morning....weather permit. I don't think I have the jones to just hand launch it. Maybe I should build a rolling dolly to build up some speed and "gently" fly away. I'll try to get some video of it. My digital camera isn't the best but it's better than nothing

[Lost In OC]

Ok, so I just got back from the hobby shop where I was attempting to finish the Eagle. Problem 1...the trim tabs on my computer radio dont work any more. Problem 2...the bluebird Rx is a piece of $h!t! It wont work with a brushless set up, just glitches like mad, even with proper spacing of componants. The Rx was only marginal when I was running it with a brushed motor. Problem 3...the esc I ordered was wrong, so I ended up going with a phoenix 10. All was eventually solved by hard wiring everything...alot of soldering, but I know everything is safe and secure now. I did have good fortune during all of this mess, this is a classic story. I didn't bring my radio to the hobby shop because the trim tabs pooped out on me, so I borrowed a brand new synthesized radio there. I thought wow, this new Hitec Optic 6 is a great little piece of equipment, then I looked at the price...$179. I thought no way, synthesized 6 ch. with hitec supreme Rx and charger for this great price. I went up to my good friend the "manager" and asked about the price. We looked up the wholesale price which just happened to be on weekly special for $130 dealers cost. I get $5 over cost there, so the "manager" knocked off $70 for the Rx, $20 for the charger, and $5 for the xtal...stuff I don't need that came with the radio....stuff he can re-sell. he also gave me a $20 credit for the crappy bluebird Rx.......the long of it, I ended up with a $240 radio for $20 + tax.....wouldn't want to cheat uncle sam. Bet you're jealous!!!! neener neener neener!!!!!!

[HanksGB]

Yeah, that sounds like a storie from the old job. At my new job all i get is free coffee, which isn't that bad considering how much i drink that stuff. Next time you're down there tell all they guys I said hi. Hoping to test fly the cap this weekend. Also my friend is going to give me ten feet of doculam to try, if i like it you want to split a roll?
henry

[esb-help]

oc,do'nt worry about the hand launch,at that weight its kind of hard to break anything unless you do a high speed dive into concrete :eek: trust me on this one,been there done that,my f-15 is built up formers and stick and i even stuck it in the grass once :D their so light the can'nt even penetrate the grass to topsoil :p seeing that your all sheeted you should have no problem,good luck and have fun ;)

[Lost In OC]

OK so I flew her. With the short feigao 12mm motor, flight was only mediocre. First flight was tail heavy, nose high, holding elevator on the verge of a stall. With a few dimes and a rock held in place with some soda staw wrappers....no one said this was professional business.....the second flight was much better, but I just wasn't getting the speed I hoped for. 25mph at best, not enough for me! I went home and replaced the short 12mm feigao with the longer one and added a 450 3 cell lipo. Needless to say, this time the little jet rocked!!!! Imagine somethin the size of a paper plate doin about 70 mph!!!!!! My success wouldnt stay for too long, as I pushed the plane harder and harder, my motor got hotter and hotter. The motor got soooo hot, the prop melted off the shaft when I was in a really akward position about 5 feet off the ground doing around 60 mph.....bad news!!!! The plane hit the ground knife edge and ungracefully returned the model to kit form, not that it was a kit to begin with,but you get my point. Ohwell, guess the next one will be the same size, but a ducted fan!!!!

[HanksGB]

Chris,
At least you got a transmitter out of it. Next time, F4 it's the only way to fly...
regards,
Henry

[nopistons96]

sorry to hear about your luck ...OC. but i did almost fall off of my chair reading about it. a 70mph paper plate..!! haha. thats some funny stuff right there. looking forward to hearing about the edf experience. any video?

mike

[rcjetpilot]

...The plane hit the ground knife edge and ungracefully returned the model to kit form...

Oh no! this was such cool thread to watch. At my club we have 2 or 3 guy's that are really into the micro size, so I pointed them to this thread:)

If it helps at all, they all meet the same fate in the end :eek: Sure Like to see another build...

Bob.

[Lost In OC]

no video, unfortunatly. I got really antsy to fly it be4 I could borrow a digital camera. More tiny stuff on the way!!!! I wan't to go smaller and faster. I think we should start a thread of "cheap" speed projects using the feigao and similar size motors. Seriously, the f15 cost no more than $7 in balsa, and thats only because I used the contest stuff! Post some ideas!!!!

[esb-help]

wallmart $3.50 foam glider,all you need is the main wing,no spar just some filiment tape and some color tape,used a fiegao 12mm bl with a 3x3 prop,cc micro-10 esc,2-4.4g servos and a 3s1p kokam 340 mah batt auw is 3 5/8oz.(100g) ws is 20in.,flys like stink :D i'm recovering it and recessing the electronics now i know it flys,wait till i put my cdr motor on :eek:

[Lost In OC]

Nice scale!!!....I bought the same one at wallmart for 10 or 15 bucks. Works like a charm.