I've had a Phoenix 2000 glider from hobby king sat in my shed for about a year now and after seeing the release of the new sky mule i had an idea ;)
Equipment:
BL Motor A2826(2212) 1400Kv (x2)
Robotbirds Basic-20A Brushless ESC (x2)
SERVO - EMAX METAL GEAR ES08MA
RB UBEC 5A With Filter
EzUHF Lite
Battery - 2200-3000 mah 3s
FPV Equipment:
Lawmate 2.4GHz 500mw (if i can find one in stock!)
FPV-25CE 1/3 Inch Exview HAD II CCD Camera 650 Line Sony Effio-E
The fuse is blow moulded so its stupidly strong and has loads of room inside for FPV gear and the like.
I started the build with the motor mounts, I used 2mm balsa sheets, doubled up for the motor firewall to give a bit more strength. I adjusted the angle so the motors are facing down a couple of degrees. I forgot to take pictures actually building them but here are the finished mounts glued to the wings (unpainted):
(http://s4.postimg.org/q6xgaufbt/IMG_1999.jpg) (http://postimg.org/image/q6xgaufbt/)
(http://s13.postimg.org/rafye96er/IMG_1998.jpg) (http://postimg.org/image/rafye96er/)
Whilst i was waiting for the gorilla glue to dry I set about fixing the pan and tilt mechanism for the camera onto the canopy. I could have gone for the more streamlined approach and only been able to pan the camera but I'll be using a trinity head tracker with it so i went for the full works :P (roll axis might be added in the future).
Pretty simple, drilled a 2.5cm hole in the canopy and fixed the mechanism base to the underside with screws:
(http://s1.postimg.org/cjj5iw123/IMG_1992.jpg) (http://postimg.org/image/cjj5iw123/)
(http://s1.postimg.org/v6mnz20rf/IMG_1993.jpg) (http://postimg.org/image/v6mnz20rf/)
Looking good :)
Thats going to be different for sure looking forward to seeing how it flies :)
dizzy :)
looking good! Will watch with interest
regards
Andy
Got a bit done on the wing electronics tonight, used a soldering iron to run larger channels for the ESC power wires, Just a test fit of the esc's for now. I'm also mounting the ESC in the Flap servo cut out (had to extend it a bit). Should get some good cooling out on the wing and in the prop wash :)
(http://s17.postimg.org/n2x44vifv/IMG_2001.jpg) (http://postimg.org/image/n2x44vifv/)
(http://s17.postimg.org/tfc9epli3/IMG_2002.jpg) (http://postimg.org/image/tfc9epli3/)
(http://s17.postimg.org/7ripqivq3/IMG_2003.jpg) (http://postimg.org/image/7ripqivq3/)
I like the look of this mod. Very nice
Sent from my GT-I9300 using Tapatalk
Finished this build this afternoon after the servo extension cables, receiver, props etc arrived this morning.
Ive had to put 40g of lead in the nose with a 2200mah 3s behind that. Happy with that as I've got loads of room for either a bigger battery or if I'm wanting to keep it light i can move the battery forward 2/3" .
There are 5 cables connecting the wing to the fuse (servos, esc power/signal) so its a bit cluttered with all that and the XT-60 plug enabling me to remove the wing but like i said, the fuse is pretty big inside and it all fits in quite well :)
Took it down the field for the maiden. Very un-eventful ;D
triple checked all connections and control surfaces, 3/4 throttle with a gentle throw and it was away. a few clicks of rudder trim and it was dead on :)
Cruises beautifully at 1/4 throttle and it still glides like it should. Overall I'm VERY happy with how it turned out :) just need another Vtx to arrive from canada and then I can have some proper fun :P might make it look a bit nicer whilst I wait ;)
Will get some pictures and videos of it flying as soon as i can
congrats on the maiden. looking forward to pictures!
regards
Andy
Well done sounds like you got her spot on first time :D
dizzy :)
(http://s1.postimg.org/dwnhf11uj/IMG_2007.jpg) (http://postimg.org/image/dwnhf11uj/)
(http://s1.postimg.org/wnpep6wez/IMG_2008.jpg) (http://postimg.org/image/wnpep6wez/)
(http://s1.postimg.org/j9cbt5pqz/IMG_2009.jpg) (http://postimg.org/image/j9cbt5pqz/)
(http://s28.postimg.org/yb5ygu515/IMG_2010.jpg) (http://postimg.org/image/yb5ygu515/)
(http://s28.postimg.org/yqma6yxa1/IMG_2011.jpg) (http://postimg.org/image/yqma6yxa1/)
(http://s28.postimg.org/4qwiy5t6h/IMG_2012.jpg) (http://postimg.org/image/4qwiy5t6h/)
(http://s28.postimg.org/npm34typl/IMG_2013.jpg) (http://postimg.org/image/npm34typl/)
This looks great, thinking of doing something similar with my walrus since it's sat doing nothing at the moment.
Any advice for the build? Was the down thrust required?
Please excuse my ignorance but why does a push motor have down thrust but a front pull motor doesn't?
I'll be honest with you lads, I know little about the physics of flight and I did absolutely no calculations when building this. I just looked at a multiplex twin star and went from that.
I did angle the motors down ever so slightly, looked like the right thing to do :laugh: in practice it flies perfectly throughout the throttle range. On full throttle it doesn't pitch up or down, just maintains the same pitch.
"If it looks right, it'll fly right"
Quote from: Paul881 on June 02, 2014, 06:17:20 PM
Please excuse my ignorance but why does a push motor have down thrust but a front pull motor doesn't?
Pull motors do usually have down thrust, but just far less than a pusher, typically only a couple of degrees down thrust. I think it also depends on where the moot is in relation to the centre of the main airfoil / wing.... Like James says, if it looks right.... ;D
Edit; Wikipedia to the rescue... http://en.wikipedia.org/wiki/P-factor (http://en.wikipedia.org/wiki/P-factor)
So that explains why a single pull prop is offset to the right or left depending on prop rotation, but I'm still not sure why push motors on/behind the wing have such a sharp angle compared to a front mounted motor.
Because of the high thrust line pushing the nose down.