Hello Guest it is February 25, 2021, 05:52:51 AM

Author Topic: biggish servo spindle  (Read 8365 times)

0 Members and 1 Guest are viewing this topic.

Offline fast89

*
  •  144 144
    • View Profile
Re: biggish servo spindle
« Reply #30 on: November 22, 2016, 08:36:54 AM »
I have not tried setting as a spindle yet. i think i can get that working. I did try as a linear axis and that made no difference. I reset the eprom to factory settings and started over. That didn't make any difference either. Did a little more tuning and it is more responsive now but still only goes in one direction from mach3 even though i can see the dir. pin change from 5v to low.  From Ultraware, it will do everything it is supposed to, for, rev, and rpm. This just keeps coming back to poor pulse stream from mach3. I finally got the oscilloscope function to work. Yeah the pulses don't resemble a square wave at all. Maybe you have good luck with these because of the smooth stepper outputting cleaner pulses?

Offline fast89

*
  •  144 144
    • View Profile
Re: biggish servo spindle
« Reply #31 on: November 22, 2016, 10:42:59 AM »
I swapped with the y axis and it does the same thing. Only goes in 1 direction. Looking at the oscilloscope, going forward has nice distinct pulses although not close to  a square wave. Going in reverse is a mess of jumbled pulses. Its no wonder it doesn't move, it doesn't know which way to go. The pulses are erratic and unevenly timed/spaced.  Maybe it is just damaged inputs on the drive. My other drives work fine with the pulses that mach3 and the B.O.B are putting out.

Offline Hood

*
  •  25,838 25,838
  • Carnoustie, Scotland
    • View Profile
Re: biggish servo spindle
« Reply #32 on: November 22, 2016, 01:35:53 PM »
It does sound like there may be an issue with the drive :(

One thing you could try if you wanted to test it out is take the encoder output from one of your other drives and input them to that one. You could then set it up as a slave drive and encoder follower and see how it performs. If it works ok then it can't be the inputs that are screwed as they are the same inputs used for Step/Dir.

Offline fast89

*
  •  144 144
    • View Profile
Re: biggish servo spindle
« Reply #33 on: November 23, 2016, 06:37:10 PM »
Yes, it was the drive. Bought another one for $300 on ebay, threw it in there today and the spindle rotates forward and reverse as a-axis just fine. Now to figure out the spindle setup. I'm using parallel ports so i am greatly limited in pulse frequency. I'm thinking maybe some electronic gearing to lower the required steps for a given rpm. Or maybe using the command +/-  inputs.  I wish there was the option of naming an input pin for forward and reverse and 0-10v for speed.

Offline Hood

*
  •  25,838 25,838
  • Carnoustie, Scotland
    • View Profile
Re: biggish servo spindle
« Reply #34 on: November 23, 2016, 06:47:23 PM »
You could do a workaround for the analogue voltage, I have done it in the past.What I had was a double pole double throw relay and used that to invert the 0-10v so that you were feeding the drive with  -10 to 0 or 0 to + 10 depending on the way the spindle was to rotate. I used the M3 to enable another relay to put the voltage to the drive  and the M4 operated it as well but also swapped the original relay.

Having said that Step/Dir would be a better option in my opinion, it would give you much better control and would even allow you to rigid tap if you wanted by using the SwapAxis() in Mach and changing it to a rotational axis.

Your motor is 4000rpm and if I recall your kernel in Mach is 60KHz, that would mean the max RPM without electronic gearing would be 450rpm so to get full rpm you would have to set a 1:9 for the electronic gearing.

Hood

Offline fast89

*
  •  144 144
    • View Profile
Re: biggish servo spindle
« Reply #35 on: November 23, 2016, 07:11:46 PM »
I don't see gearing as an option on the digital inputs though.

Offline Hood

*
  •  25,838 25,838
  • Carnoustie, Scotland
    • View Profile
Re: biggish servo spindle
« Reply #36 on: November 23, 2016, 07:19:09 PM »
If you look at post 19 I attached some pics, the bottom one is where you would enter the gearing against Preset 0.

Offline fast89

*
  •  144 144
    • View Profile
Re: biggish servo spindle
« Reply #37 on: November 23, 2016, 07:28:09 PM »
Yes, but how do i switch between presets. Its not an option in the digital input drop down menus.

Offline Hood

*
  •  25,838 25,838
  • Carnoustie, Scotland
    • View Profile
Re: biggish servo spindle
« Reply #38 on: November 23, 2016, 07:35:01 PM »
There are Presets in the Inputs, see pic, however you  don't need them if all you are wanting to do is set one electronic gearing only.
Preset 0 means you do not have to have any inputs configured as that will be the default scaling, ie 1:9, 1 master pulse = 9 drive pulses.

Offline fast89

*
  •  144 144
    • View Profile
Re: biggish servo spindle
« Reply #39 on: November 24, 2016, 08:45:49 AM »
Ahh. got it. With 360 steps in mach3 and the drive set to 1:87, i get the rpm i want and well within mach3 pulse limits.  Next problem: At 4000rpm i have aver 20,000 counts of error. Which is fine but occasionally it gets an e19 alarm because of it. I can't find where to increase the amount of allowable error.