Monster Quad in Desperate Need of Reasonable PID

I think I bit off more than I can chew. From looking at other configurations on the forums I may have built a quad that seems to be on the XL side.

frame:  Personal monstrous design. 3/4 Aluminum tubing rigging
controller/autopilot:  APM2
esc:  Turnigy Plush 60A
motors:  E-Flite Power 32 770kV
propellers:  APC 13x4 Electric
motor to motor distance: 36 inches

battery: Turnigy 20-30C 4S 5000 mAh
total weight: ~8 lbs
radio: E-Flite LP5DSM

Can't seem to get this thing in the air more than 30 seconds at a time and when it's in the air, it's a constant struggle to keep it from hurting me and my amused and frightened coworkers. It feels like the system is not exerting its corrections quick enough to reach a level flight and I have to always compensate through my controls and end up over correcting. Usually ends badly for me or the quad. It drew blood couple times.

I've been digging through the forums to see if there is any successful quad that resembles mine and follow its PID settings but have yet to find one.

Can anyone start me off on the right path?

I have attached the settings that I'm crashing on.

Someone pointed out that I may need to move my ESC's away from APM2. So I have done that. Need to have a testflight once the props arrive. Also suggested by the same person that I might want to put APM2 on more solid footing rather than suspended. Will try that as well.

CurrentParam.param

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JeffBetts_KK4MTC July 7, 2012 at 8:57pm

Sounds like you should increase the RateP gain to make it not quite so sloppy, and adding some expo to your transmitter should help with the over corrections. Do you have a transmitter with rotary knob you can use to tune parameters while flying? My DX8 does, and it's a HUGE help in tuning. Best of luck.
Derek E July 7, 2012 at 4:46am

I am working on building a carbon fiber frame that will be 40 inches motor to motor. However, until all of the parts arrive (waiting on wire, connectors and screws) I have built the quad on a 450mm (17.5 inch motor to motor) frame that I got cheap off ebay in order to make sure that all of my parts are working. Perhaps you could try a smaller frame for now to make sure the only change is the frame (really just motor location on your existing frame would work) which make the difference. That would help answer your unknowns like ESC location and APM mounting method.

I wish I could help with PID tuning, but I am simply not there yet. Hopefully I will be by the end of next week.

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Monster Quad in Desperate Need of Reasonable PID

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