[vmgobinath]

Hi,

I have CNC Router with Sparkfun stepoko board and I have connected Servo motor(5v) with PWM pin and works fine. But yesterday I installed the limit switchs and enabled Homing too.

Initially not responded for homing But after changed polarity switch, works fine.

But unfortunately, my servo not responding now.

If I change the polarity, PWM Servo works fine but not Homing.

What to do...Reply from experts..

 

[PhilBa]

I think you mean spindle and not servo. What exactly do you have? 3 phase with a VFD or a DC spindle?

It seems you are getting PWM - hard to judge actual PWM duty cycle by LED brightness, it's not a linear response. I would check the connection wires to see if your spindle is actually seeing the PWM.

Did you change Max Spindle Speed? ($30) What is it currently set at? What is Min Spindle Speed set at? ($31)

 

[vmgobinath]

I think you mean spindle and not servo. What exactly do you have? 3 phase with a VFD or a DC spindle?

It seems you are getting PWM - hard to judge actual PWM duty cycle by LED brightness, it's not a linear response. I would check the connection wires to see if your spindle is actually seeing the PWM.

Did you change Max Spindle Speed? ($30) What is it currently set at? What is Min Spindle Speed set at? ($31)

Hi,

Thanks for your reply. Mine is a Mini CNC router. Yes, you are correct. Spindle PWM only.

I found that problem with polarity.

If I change the polarity, PWM Servo works fine but not Homing.

If I change the polarity in the opposite side then Homing works fine but not Servo.

What to do...Any idea?

 

[kp91]

I think we need to see how the limit switches were wired up. If it worked fine before the limit switches were installed, I would start there

 

[PhilBa]

Yeah, clearly the limit switches are interfering with spindle PWM, maybe you have the limit switch hooked to the wrong pin or you are shorting the limit switch to the PWM output. examine your controller circuit board for shorts, stray bits of metal or bent pins. Anything made of chinesium often has quality problems.

 

[vmgobinath]

I think we need to see how the limit switches were wired up. If it worked fine before the limit switches were installed, I would start there

I hope Polarity matters.

If I Change the Polarity servo working fine. But Homing not working

 

[vmgobinath]

Yeah, clearly the limit switches are interfering with spindle PWM, maybe you have the limit switch hooked to the wrong pin or you are shorting the limit switch to the PWM output. examine your controller circuit board for shorts, stray bits of metal or bent pins. Anything made of chinesium often has quality problems.

Thanks a lot for your support. I have checked the Limit switches and when I pressing the limit switch, the lights are responding to the corresponding axis.

PWM pinout totally away from the Limit switches...

:crying:

 

[PhilBa]

That doesn't necessarily mean anything. Do you have to physically disconnect the limit switches to get the spindle to turn on?

 

[vmgobinath]

OK Thanks a lot...Sure. I will physically disconnect and reconnect all the limit switches. I will update you.

 

[vmgobinath]

Dear All,

Thanks a lot for your kind support. Problem gets solved.

Solution:

$5=1 (Invert limit pins)


Thanks a lot for your kind support

 

[PhilBa]

That's good. So, the spindle had nothing to do with the problem.