Proof the foamy quadcopter flies
Today was the first flight outside the confines of the garage. It was quite windy at the local oval making it fairly difficult to maintain stable flight. It's not meant to fly nicely, it's meant to look weird and fly weird and that's exactly what it does.
Flite test: how to add lights
So far I've built the rcpowers.com extra 300 foamy and added a HK401B gryo and I still haven't flown it. Maybe I should add some lights just for good luck
rcpowers.com extra 300: Gyro install
I haven't even flown version 2 of the rcpowers.com extra 300 foamy but what better plane to try out the hobbyking 401B Gyro on. I had problems getting it to work with the Fly-Dream 2.4Ghz receiver so I swapped over to a JR 36MHz synthesized Rx and it worked a treat.
time lapse build video – extra 300
What started out as an instructional video on building a foamy, turned into a time lapse video of the build. I used Vegas Pro to capture, resample and speed up the playback to condense a few night work into about 90 seconds video. I built it out of 5mm foam core artboard which overall I think comes out too heavy. During the build, I used a heatgun to remove the cardboard layer from the ailerons and rudder. This came to about 45 grams of weight removed from the plane. Imagine how much I could save if I skinned all the cardboard from the foam and used a few CF rods for stiffness instead.
My suspicions about the weight was confirmed with a maiden flight on Sunday past. It flew ok and would hover but needed about 90% throttle to do so. I think I'll try to lighten this version and build another one without the cardboard skin.
rcpowers.com extra 300 foamy
it's all cut out of 5mm foamcore artboard from the art supplies shop (Riot Art, about $16 for an A0 sheet).
I've loosely pieced it together here (no glue) for an idea of size and look.
Break out the hot glue!
kf Delta Foamy Version 2
My handmade engine mount on the kf Delta Foamy version 1 wasn't so great. A 3mm square plate of ply hot glued onto a foam "firewall". After a lengthy flight on a 2S 1000mAH battery, the motor wouldn't turn. After taking it apart, I found excess hot glue on the mount had heated up during the flight, come in contact with the rear of the motor and after it cooled, it all gummed up.
So onto version 2. Rudder control, a thicker more consistent step and a Turnigy 2730 Brushless Motor 1500kv (http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=8618) on a proper engine mount.
S-l-o-w flying KF delta build – the prop maketh the plane
After the lackluster first few flights I got around to putting a 9047 GWS EP Propeller (228x119mm) and wow what a difference. Same 800maH 2S 7.4V battery and RCTimer1400kV 2204-14 motor mind you but with the larger, more efficient prop I was getting good vertical performance and could slow fly stable enough to do a couple of laps in and out of the soccer goals (obviously no net up at the time 🙂 ).
I've still got a couple of battery and motor combos to try out but for now I think I'll put some paint on it to help identify which way is up and have fun with the current setup.
S-l-o-w flying KF delta build – Maiden Flight
Time to see how this baby goes. I used hot glue all around, control horns, motor mount, bottom skin, step.... and everything has held together well. For the maiden flight I used an RCTimer1400kV 2204-14 motor, an EP 7035 propeller, a 2S 800mAH lipo battery. All up weight was 182 grams / 6.4 ounces. Performance was underwhelming. The first few launches were at full throttle hand launch and floated into the ground. A few more gentle shoves got it up in the air and flying. It wouldn't climb vertically but would gradually gain height after a few laps and gentle turns. Rolls were very fast but I'd lose height quick. Inverted flight required about half down elevator suggesting a CG too far forward. I was worried it was going to be too tail heavy according to the recommended CG and made the effort to move the servos forward. After moving the 2S 800mAH battery a bit further aft I think I found a better balance.
I think I might try a 3S 1000mAh battery and maybe an 8 x 4.8 SF prop. Or maybe build one half the size with the same motor and battery - that should get around ok. Ideally I'd like to comfortably get around on half throttle and have plenty in reserve to recover from tight spots.
I got some footage from the keychain cam and will post that soon.
S-l-o-w flying KF delta build – motor mount II
Some 3mm ply behind the motor, probably overkill and a bit heavy but it's what I had at hand, some hot glue and the engine is on. I had to widen the gap for the prop by about 7mm to fit it all in.
With the motor in place I could get a feel for how it would balance. With an 800mAh 2S lipo all the way up front it was still well tail heavy. Add the ESC and receiver up front and it starts to balance out. The challenge will be to get all that gear up forward as possible without deforming the profile of the wing. As per the examples photos in the rcgroups thread, I was going to but the battery on top with the ESC and RX on the bottom. I was hoping to keep the control rods as short as possible by keeping the servos back near the elevons but due to balance, the may have to go further forward.
On to a question, usually the motor is mounted the other way around (baseplate behind the motor relative to the forward direction of the plane) but on this one it's reversed (a pusher). I'm guessing it's not right to simply reverse the direction of the motor so that it starts pushing. The prop is designed to cut through the air most efficiently with it's leading edge so I guess the right thing to do is flip the prop (keep face of the prop pointing towards the front). Maybe that's the obvious answer? Dunno, never built a pusher before.
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