At a loss! Tricopter troubles

[SGrog]

Hello!

So, after a long hiatus, I am back and trying to pick up where I left off. Things were going well, but Ive just hit a wall. I can power the unit up, and sometimes one motor will spin, sometimes two will, but never all three, and the servo does not move. I am running the following:

Frame: Tricopter V4 from RCExplorer
Motors: Cobra CM 2814 - 700 kv
ESC: Cobra 30A Opto Multirotor ESC
BEC: Cobra 6A Switching UBEC
Props: 12 x 4.5 MR (2), 12 x 4.5 MRP (1)
FCC: Arducopter Computer with a external compass/GPS module
Rx: Spektrum AR6210 (2.4 GHz)
VTx: RMRC Cricket (V2) (5.8 GHz)
VTx Antenna: RHCP
Video: Mobius Action Cam
Telemetry: 3DR 915 MHz radio set

Output pins are as follows:
1: RH motor
2: LH motor
4: Tail motor
7: Servo

Input pins are as follows:
1: Aileron
2: Elevator
3: Throttle
4: Rudder
5: Aux 1
8: Power from BEC

Current issues:
* One or two motors will run, but never all three.
* Servo does not move
* Wire management - suggestions? I would like to put my VTx behind my GPS.



I would like to get it up and going, otherwise it is going to turn into an expensive paperweight

 

[Sid]

I would start with and esc calibration

 

[SGrog]

I thought I had calibrated them correctly, turns out I had not. The three motors run in unison now, but when you get to say about 40% throttle, the motors sound like they drop in tone (like less power being applied), could that be a Mission Planner setting? I also removed the power connector (red wire) from each motor ESC, that seemed to help as well.

Also, the servo works after I took the UBEC and plugged it into the OUTPUT side, instead of the Input side. I still need to figure out how to calibrate it, but may have a test flight tonight yet!

 

[makattack]

I might warn that before you even think about test flying the tricopter, you do a bit more bench testing and troubleshooting. Especially if you even are considering using any of the GPS assisted flight modes. In fact, I would not recommend even configuring any GPS flight modes until it flies well in stabilized or even acro modes, and while flying in those modes, download the flight log into mission planner and compare the GPS recorded coordinates and actual flight paths to make sure you don't see anything weird. I'm just worried that GPS antenna/external compass setup you have is too close to noisy electronics and you'll have a bad GPS signal and inaccurate compass readings.

 

[SGrog]

I totally agree with you on that, I don't fly anything unless it has proven itself on the bench (consistency of results, and through measurements), static under various scenarios (with out props!!!), and then in short hops under various scenarios.

To drive your point home makattack, I tested the GPS readouts (outdoors, no props, and with motors on (to make as much noise as possible)) with the antenna where it was in the picture, as well as in front of the unit as far forward as possible. Where it was mounted in the pic, I was placed within 40 feet of my actual location, putting it a foot in front of the unit, I was put within 10 feet, and generally much closer then that.

With that said, I got the software to finally work (had to change several settings), and servo to work (let servo center self, then reattached motor, and plugged the servo power cable in (oops, that was a rookie mistake...)).

I think with all that, and the addition of other systems, It is time to rewire. What recommendations would everyone have?
Right now Im thinking of shortening the wires off the motor, and tying those into the ESC's right by the motors, instead of down the rear boom. Putting the GPS on a mount on the rear boom, then putting the OSD on one of the two front booms, and the VTx on the other boom to ensure enough distance between transmitters and ESC's/UBEC's

Any other ideas?

Thank you for any input!

 

[JimCR120]

Just a tricopter noob wishing you well on your return. Mine flies and I'm happy to offer details but I'm still learning a lot.
http://forum.flitetest.com/showthread.php?27884-RCExplorer-Tricopter-V4

 

[Rotorblade]

Run through all the ground station stuff, calibrate the sensors, compass, GPS, you probably know that song and dance. I am rusty with my APM knowledge. My suggestion is to get it all working first and then make it look nice. You're on the right track with trying to keep the GPS from the VTX.