QuadYcopter Maiden Flight video
There's a few different names that might be applicable like a Y4, Inverted V-Tail, Y-Copter but I think I'll call it the QuadYcopter and it flies! All I had to do before this video was reverse the direction of two motors and it flew better than expected considering the lengths and angles are all eyeball precision.
I expect the QuadYcopter should deliver the best aspects of Quads and Tris;
- No mechanical tilt needed on the rear motor (tri negative)
- Larger unobstructed field of view looking forward (tri positive)
- Non symmetrical airframe which should be easier for orientation at long distance (Quad negative)
Notice in the video, it's quite twitchy in pitch. I reckon that's related to the CoG which I've moved forward by mounting the battery all the way forward. This isn't a big problem as I'll probably mount a GoPro up front which will further help with balance. The underside mounting for the battery means it can be moved all the way from the rear to the front to compensate for camera / cameraless flight.
I still need to mount a low voltage buzzer on the airframe. The problem is, I've started using an 1800mAh 4S battery whereas most of my other batteries are 3S. I've had to order a couple of voltage 2S-8S detectors that let the voltage be set via a jumper so I can fly with either 3S or 4S
Tricopter Flight test
I've got a couple of flights under the belt now but there's a persistent problem with the front right motor. It keeps stopping dead. This isn't so bad when its 30cm off the ground but when it's a few meters in the air there's potential for more damage. I caught one crash on the trusty little keychain camera, one mounted on my hat and the other mounted on-board the tri when the motor failed.
I checked all the connections, added padding to the gyros for vibration dampening and re-calibrated the throttle and tried again. Unfortunately the same result with that motor stopping mid-flight. I pulled out the trusty iPhone 4.0 and captured some video to help diagnose the problem over at rcgroups.
I've decided it's probably a dodgy motor or maybe the ESC. The motor is out of stock at HobbyKing so I ordered a virtually identical one from lowpricerc.com. At about six bucks each, I considered ordering three to make sure I have identical motors all round but when trying to order them, I got the "out of stock" error here as well! Turns out they had two left so I snapped up both. I'll replace the dodgy motor and keep one spare.
Just in case I grabbed a replacement ESC to help troubleshoot the problem. I went with the Turnigy Plush 18 Amp ESC because I already have the programming card and when I originally bought all the parts, this is the ESC I wanted to use but it was out of stock, surprise surprise.
So now I wait for my replacement motor until I try again. In the meantime I'll go learn some Arduino programming so I can get rid of the 4 HK401B gyros and use the Wii sensors instead. Apparently the Arduino controlled TriWiiCopter is more stable.