Author Topic: Help with Spindle RPM. %90 done jsut cant get MACH to see it  (Read 3590 times)

0 Members and 1 Guest are viewing this topic.

Offline resalles

  • Active Member
  • Posts: 5
    • View Profile
Re: Help with Spindle RPM. %90 done jsut cant get MACH to see it
« Reply #10 on: November 17, 2015, 03:34:10 PM »
(...)
i managed to get the RPM feedback working, which is awesome! it turns out that i needed to turn on spindle motor output in spindle control. that did the tick.
(...)

I have the same problem with RPM not showing, so I wanted to try your solution but I canĀ“t seem to find those menu options you mentioned. Where can I find this "spindle motor output" and "spindle control" menu?

It would help a lot to know exactly what you did.

Thanks.

Offline fodder1

  • Active Member
  • Posts: 7
    • View Profile
Re: Help with Spindle RPM. %90 done jsut cant get MACH to see it
« Reply #11 on: November 17, 2015, 04:18:29 PM »
Hi there,

I did get this working with an optical sensor connected directly to a pin.
I can't remeber the actual settings for that whether the pin was set high or low.

I did remove this feature to rebuild something and have not put it back, but it was very handy to be able to see the actual spindle speed. I was not 100% the speed was correct due to using some hearing on my spindle. The optical sensor was on the actual spindle sharft so it should be right.

I have been moving stuff around and have dissasembled the CNC + computer so it will take me a couple of days to get the info etc.
Chris

Offline rcaffin

  • Active Member
  • Posts: 990
    • View Profile
Re: Help with Spindle RPM. %90 done jsut cant get MACH to see it
« Reply #12 on: November 18, 2015, 04:54:49 AM »
Quote
I thought that Mach would compensate for the difference in the "set" RPM to the RPM shown in the RPM DRO.
Well, no, not unless you are using a genuine parallel port output. Then the PID settings are 'supposed' to work. They do not work if you are using an external pulse engine like a Smooth Stepper.
Looking at your question from a different angle, you can 'calibrate' mach3 for spindle speed. There is a 'Calibrate spindle' option under function Configs. It is a bit slow, but but it does do a fair job. You need to adjust the pulley top speed to be 'correct' as well.

Some DC supplies include a motor impedance compensation pot. This allows the supply to increase the voltage a bit when the motor is under load. Not perfect, but it can help.

Cheers
Roger