Question Wobble up and down problem as soon as I plug in USB cables

Hi Gadget999, I didn't understand (I'm Italian and I use the translator).
Can you explain it better?
Thank you
On this occasion, I wish you and all the enthusiasts a Happy New Year 2023.

A BLDC motornos normally 3 wires 120 degrees apart, there are 3 sets of magnetic fields.

My guess is the BLDC driver is not being fed a new position and cant hold a stable position over time.

Simtools and smc3 utils send regular updates on position. So the location is constantly updated.

There are many ways to fix the problem using code, but you need to learn to program first !

My brushless motor has 3 phases (H, V, W) and 3 Hall sensors.
My drive has 3 phase outputs (H, V, W) and Hall inputs (H, V, W, 5v, gnd) and works with a maximum frequency of 1Khz.

Your reasoning is correct, but then I don't understand one thing: during the oscillation, if I put a weight of 25Kg on the actuator, it stops oscillating. Because? If it was a problem you say, it should also swing when I put a 25Kg weight on it.

Try a smaller p number

Which number?

Kp

I've already tried, I got less dynamics, oscillation always present.
But I think it is useless to find the cause. I have already said that the ideal solution is to modify the code so that the motors are not active when the usb cable is inserted, ie: the motors should only be powered by the pwm when the game starts (as the xsim software does).
Is it possible to modify SMC3 so that the engines only have power when starting the game?

It could be that your potentiometers are damage or dirty at center position. While using smc3 utility if the wobble only happen at center position and gone at other position then it could be it. This could explain why when you start a game the wobble is gone. Because in some game the center position might be slightly different than smc3 default center position.

Also when you put weight it will push the position down and away from center position.

No, the potentiometers are new and clean.
It would be appropriate that the code creator gives us concrete help every now and then, especially for us who have paid for a license.

If changing Windows language to English fix your problem, but not convenient to you, maybe you can try just changing Windows decimal symbol from comma(,) to period(.)
(If your country use comma as decimal point).

I already tried to change the language to English, but it doesn't work.
Comma (,) with period (.)?

Meaning what? Explain better.

Some country use comma as decimal point eg: 3452,12 instead of 3452.12
This can be set in Windows
But since changing language doesn't fix the issue then this may not be the problem.

Your actuator is linear motion right? Like the d-box? Do you use sliding potentiometer or multi turn type that you attach directly to motor shaft?

That's right, like d-box.
I use linear potentiometers

From this picture I see that your PWMmax is only 50. That will make the motor weak. Try to increase it to 250 and see what happen.

Hi superwhitewish,
I tried to change the PWMmax value by putting "200" but it doesn't change.
I have something new: I noticed that even while driving (with rFactor, AI automatic driving), the engines go up and down (I noticed this with the HEAVE effect on straights).
Could it be a BLDC drive problem?

I did ask about your driver before because that was my first suspect.
Some driver are for continuous running. They have slow acceleration and cannot change direction immediately.

Run SMC3 and simulate square & triangle wave. If the motor keep overshoot during direction change than driver could be the problem.

Hi, I carried out the test as you advised me, you can see the result.
Tell me.

Response looks sharp. That's good. But I notice the oscillation happens in certain area only. Lower area A it oscillates but upper area B it stays steady.

Sorry but I don't have any more idea right now.


Maybe you can check the potentiometer installation. make sure they don't get loose when the actuator moving or don't get forced side way.

Hello, the potentiometer is fixed, tightly locked.. The potentiometer is of very good quality (Bourne).

I tried to increase both PWMmax and Kp, but the motors make an annoying noise (like frying).