393 encoder not moving motor.

[nxtmonkeys]

So, our lift goes down and it stalls halfway when its going up. but it doesn’t always do this. it only does it sometimes. anyone know of anything? we have 3 motors on the lift, connected to 2 turntables (big ones). we’re using aluminum for the arm.

[Highwayman]

@nxtmonkeys

So, our lift goes down and it stalls halfway when its going up. but it doesn’t always do this. it only does it sometimes. anyone know of anything? we have 3 motors on the lift, connected to 2 turntables (big ones). we’re using aluminum for the arm.

So most of the time your lift is just barely making it up and sometimes it doesn’t?
Having three motors isn’t exactly advisable as one side will be getting more power than the other side which could cause it to go crooked, etc.
You’re probably just heating up the motors from repeated use and eventually they overheat.
Also, I wonder about your thread title, “393 encoder not moving motor”? What do you mean? Encoders get rotated by motors.

[Cameron_McRae]

Can I see a picture? What is your gear ratio? And 3 motors isn’t symmetrical. Are the motors geared for torque or speed?

[AlecMiller]

What internal gear ratio do you have the motors at? What kind of weight are you try to lift? Could we see a picture of the arm in question? Are you absolutely sure all your motors are A) working and B) going the same direction with the same internal gearing?

[nxtmonkeys]

@Highwayman

So most of the time your lift is just barely making it up and sometimes it doesn’t?
Having three motors isn’t exactly advisable as one side will be getting more power than the other side which could cause it to go crooked, etc.
You’re probably just heating up the motors from repeated use and eventually they overheat.
Also, I wonder about your thread title, “393 encoder not moving motor”? What do you mean? Encoders get rotated by motors.

So, when I push the arm back up a bit, the motors start working again and the arm goes up the rest of the way by itself. it’s like the encoder decided to shut down or not send a signal back, but the wiring is sound.

@Cameron_McRae

Can I see a picture? What is your gear ratio? And 3 motors isn’t symmetrical. Are the motors geared for torque or speed?

I will have a picture soon, once I find the camera. the motors are geared for torque. they all have encoders.

@PYRObotics

What internal gear ratio do you have the motors at? What kind of weight are you try to lift? Could we see a picture of the arm in question? Are you absolutely sure all your motors are A) working and B) going the same direction with the same internal gearing?

see above for some answers. All of the motors are working (tested), and they’re going in the same direction. the arm is fast when it’s working, but it stops about halfway up sometimes for no apparent reason.

[Highwayman]

@nxtmonkeys

So, when I push the arm back up a bit, the motors start working again and the arm goes up the rest of the way by itself. it’s like the encoder decided to shut down or not send a signal back, but the wiring is sound. . .

Oh, OK, so you are using the encoders in your program for a PID controller or just a P controller or something like that?

Have you tried raising the arm without the encoders (as in just setting the motors at 127)?

[nxtmonkeys]

My team and I decided not to use that arm, because it was too problematic. We are making a new lift. We plan to use more motors on the new lift (4 instead of three). If we have any problems that we can’t solve, I’ll post them.

Thanks for the help!