Quad of the corn or why does it keep crashing?

I’ve built an S500 and everything appears to checkout - all the bench testing looks good. All the motors test as expected, radio comms are good, compass calibrated, accel calibrated, init values calculated from battery data and prop size, etc.

I’ve attempted to fly twice to auto tune however on both attempts I’ve crashed. The flight starts out fine. hover between 1-2 feet and make small maneuvers to make sure the channels are all correct. Then fly 10ft - 20 ft just to get a feel. After a minute or two of flight, the front dips and the copter descends and flys into the corn field. The second time I killed throttle to prevent having to walk through the field. It’s not easy finding a quad in corn 7ft tall.

Matek H743-SLIM
TCMM RC 30A 4in1 ESC
Emax Mt2213 935kv
10" props
4S 3300mah battery

Bin file:

Any help is appreciated!

cant see that without an apple account. all the s500 clones are garbage, the original by SK S500 by hobbyking had carbon in the arms, the clones don’t so the arms are like rubber.

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Ok link updated. I don’t share files too often so this might not be any better.

I hear you about the frame. This one seem pretty solid and the last one I crashed had carbon in the arms.

10 inch propellers are far too big for those motors on 4s, you should be running 9x5 propellers at the biggest.

Also the vibration levels are rather high

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with vibrations that high it wont be able to stay upright, it will eventually just start rolling as it looses track of what way is up.

And what is going on with the height?
It shows you flown more than 2000m (over 6500 ft) above ground!

I think your looking at the GPS altitude, he is getting non stop compass and gps errors so its probably that your seeing.

honestly, its hard to be sure what caused it to crash.

Start with better propellers, the cheapest ones you can buy are rarely balanced, find something branded they are generally made to a higher standard to get the vibration levels down. genuine DJI phanom 2 propellers 9x3.8 or 9x4.5 will fit and will be very high quality.

If you still have vibrations, you will need to check your motors, you might have damaged one in the crash.

Move your compass and gps up and away from the rest of your vehicle and disable the internal compass. to try and clear the gps and compass problems your having.

Yes, you’re right, did look at the GPS values.
Sorry, my bad.

Ok thank you! Sounds like there are several issues I have to deal with.

For the GPS, how should I raise it? I used a mast in the past but it was a headache having to replace it often.

I’ll get the props on order and see if that solves my vibration problem. I have carbon fiber props and I made sure they were balanced but if they’re too big then I’ll have to change them out.

Been making my own mast in the past but found they (3D printed version) don’t like the vibrations and stresses by sudden movement. → Eventually they snap or come loose.
Recently changed to those little commercial type masts. Some are of light metal constructions others are available in carbon fibre design.
The other option I’ve seen often is a little cover over the FC and then GPS on top of that.
However, I don’t like that idea much as depending on FC and other equipment used RF interference can become a problem.

I should asked in the last post - what values did you show in the trend for displaying compass and GPS errors? I have a 250mm that uses the same GPS/compass combo so I should probably check it as well.

I’ve found several values to look at - ERR.Subsys and Err.ECode, GPS.Status, MAG.Mag(X/Y/Z)

For what it’s worth, it was a bad motor. Replaced darn near everything else before it finally gave out and wouldn’t run any more. Put a new one on and it’s been running fine.