Major glitching on 2.4 gHz

[Jack3M]

Was running my 4200 XL today and initially got some glitching on the tracks while using the digging arm. I thought at first I was hitting the levers for them. Not. As time went on, I noted the pump motor had slowed. Shut down, rebooted. Next time it glitched it did the same thing to the pump. The only way to resolve is to shut down and reboot. Battery(s) voltage just fine on radio and excavator. The last time it did it, was a different battery and it was so bad all the channels got hit, including the hydraulics. My home is probably pretty clean as far a interfence is concerned.

I have not had time to check this out. Wondering if this sounds familiar to anyone else. It has been flawless up to now.

[SmallHaul]

It is very rare that 2.4ghz will have radio interference. The next time you experience the problem go to your "display" mode and closely watch the bars that represent each channel that is glitching and see if the bars/channels are moving without touching the radio. If so the control board on the radio is probably bad.

[thebigo]

Sounds like you have a servo malfunction. Check for leaks off of any hydraulic connections, especially around or near servo's. I am almost 100% sure it's a servo short circuit.

David

[Mustang46555]

If the servo checks out you might want to try this. It's not supposed to happen with 2.4ghz but does your pump and track motors have capacitors on them? I swore I had a bad ESC when I powered the ramps on my drop deck trailer it glitched so bad while raising the ramps. I put a couple of small "old school" caps on the motor and the glitch went away.

[Cooper]

Originally Posted by thebigo

Sounds like you have a servo malfunction. Check for leaks off of any hydraulic connections, especially around or near servo's. I am almost 100% sure it's a servo short circuit.

David

I agree with David, had same problem before. Sometimes the oil can leak into circuit board through screw hole that is normally filled with a screw for the servo horn. Mating to the valves eliminates the horn leaving open path for oil. Or simply around spline. It's not any interference from external sources, it's probably feedback interference. Unplug one servo at a time from rx and operate for a bit, see if one (or possibly more but unlikely) gives that interference. And if not servos keep testing anything else like track esc's or turn esc.

[TheBennyB]

Might be a reach, but you could also eliminate some of the BEC voltage hitting the RX. Take out the red lead to the RX from the 3 ESC's running the track motors and slew motor and just let the pump ESC BEC power everything. It has a 5amp BEC. I blew a servo and while replacing it decided to upgrade the other ESC's to sabertooth's. I was getting a glitch in one track motor and couldn't figure it out till I read about BEC overloads. Since removing unneeded BEC voltage I haven't seen any glitches.

[bigford]

Same thing with the China kat. tracks,slew are
Chinese esc. The pump is on a e-flite 60 as the main
Esc. I also replaced the tower pro servos to better ones

[Jack3M]

Ok, I spent some time on this yesterday. It seems that letting the sticks go and return to neutral will cause this the most. But, use of bucket seems to be the worst, followed by main boom.

It does not seem to do it as much for the arm as the boom which is same stick as bucket.... It hits the tracks first, the rotate second, and the boom next. Sometimes it hits every control function.

I started to put in a whole different radio, but it does not have 2 centering sticks. As I think on this, I think I will go ahead and still try that to eliminate the radio over the servos and wiring inside the machine.

Have not had leaks, a spill, but no leaks. Don't think the servos got wet, but will check

[Jack3M]

Yes one servo is causing this, the one for pressure relief. Now to figure out the proper replacement.(s)

[bigford]

Are they full size or mini servos
I use Hitec mg- mini

[TheBennyB]

They are full size. One thing to watch is if the stock horn stripped at all. I cut down the
Hitec red four arm horn to fit the valve and swapped to a Hitec HS-645 MG servo.

[Jack3M]

I had one that fits, used it, then went out and played. Worked fine for awhile, then a different servo cooked. Just ordered a whole set from HobbyKing.

[pigeonfarmboy]

Doesn't sound like glitching as much as servo oscillation. If letting go of the sticks triggers the problem, that's likely the case. Poor-quality servos can't keep up to radio inputs or have so much play in the gearbox it causes the pot to never properly find center and begins oscillating.
Another thing to look at is how much power the servos are drawing. BEC circuits in cheap speed controllers are garbage. Try to eliminate the issue by plugging different combinations of servos into the receiver.

[Jack3M]

Replacement of all the servos resolved the issue