Hello Guest it is January 18, 2020, 06:20:03 PM

Author Topic: PWM Mach Settings  (Read 9700 times)

0 Members and 1 Guest are viewing this topic.

Offline budman68

*
  • *
  •  2,360 2,360
    • View Profile
PWM Mach Settings
« on: May 16, 2010, 09:11:54 AM »
Hi all,

Ok, I have my little Taig CNC Lathe torn apart, and I'm ready to fire up my MC60 treadmill controller with the Gecko G540. Now Peter Homann already helped me with the wiring (thank you Peter!) but I need to know exactly what changes to make for setting up Mach.

Just a bit of background info for you. I've already tried settings from a user on the "Zone" that worked when I benchtested this setup (although I don't think the speed is correct), HOWEVER, that was with a completely different G540 and treadmill controller, although they're the same exact units as what I have installed on my Lathe. It works perfectly on my benchtest setup, but for some reason, it's not working on my actual Lathe setup. Basically as you can see by the diagram below, the vfd connection from the G540 acts like the potentiometer. Peter gave me a great idea to install the switch to be able to manually control the speed, as a nice alternative.

Keep in mind, the PC is fine as this is what I use to run my Taig Mill and my Taig Lathe, every day, with no issues.

I'm thinking I should ask you guys before I go screwing something up as I've tried to understand what each setting means but I'm at a loss as to what is actually controlloing what. I'm actually wondering if the G540 VFD control may not be working on my Lathe controller but unfortunately I'm not that bright to know for sure,  ;)  I may just take the G540 from the bench test and try that one to completely rule that out, but then everything would have to be completely ripped apart for that.

Here's a diagram of what I have at this point for wiring (it's a bitmap so it will take a bit to download):



Now while I'm sure changes would need to be made to get my motor running at the correct speed, here are the screen shots that I followed:











Thanks as always,
Dave
----------------------------------------------------------------------
Just because I'm a Global Moderator, don't assume that I know anything !

Dave->    ;)

Offline Jeff_Birt

*
  •  1,107 1,107
    • View Profile
    • Soigeneris
Re: PWM Mach Settings
« Reply #1 on: May 16, 2010, 09:25:41 AM »
Are you using your SS on the lathe? If so you'll need to set it to PWM spindle mode in the SS config screen.
Happy machining , Jeff Birt
 

Offline budman68

*
  • *
  •  2,360 2,360
    • View Profile
Re: PWM Mach Settings
« Reply #2 on: May 16, 2010, 09:27:35 AM »
Hi Jeff,

No sir, no SS, just the typical Parallel port-

Thanks,
Dave
----------------------------------------------------------------------
Just because I'm a Global Moderator, don't assume that I know anything !

Dave->    ;)

Offline Tweakie.CNC

*
  • *
  •  8,081 8,081
  • Super Kitty
    • View Profile
    • Tweakie.CNC
Re: PWM Mach Settings
« Reply #3 on: May 16, 2010, 11:20:18 AM »
Hi Dave,

If you have the benefit of an oscilloscope you could hook it up to your LPT pin 14 and observe the changing square wave PWM signal as you adjust the spindle speed slider within Mach (don't forget - you need to have a GCode loaded which issues the M3 command !!).
Then observe the 0 - 10 Volt signal at the Gecko pin 8.
If both the above are present then its your wiring (assuming nothing is broke).

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.

Offline Jeff_Birt

*
  •  1,107 1,107
    • View Profile
    • Soigeneris
Re: PWM Mach Settings
« Reply #4 on: May 16, 2010, 11:46:06 AM »
Good point Tweakie, you have to tell Mach to do something before you can test for it. You can also just issue a commanded spindle speed, say S1500, and them an MS by the MDI line...
Happy machining , Jeff Birt
 

Offline budman68

*
  • *
  •  2,360 2,360
    • View Profile
Re: PWM Mach Settings
« Reply #5 on: May 16, 2010, 11:48:28 AM »
Hi Tweakie, thanks for the info, but no scope here.
As for the spindle, when benchtesting it, I turned the spindle on (Mach screen Spindle Button) and it worked perfectly, once I inserted a speed into the Speed DRO ;)

So the screenshots of Mach look correct to everyone?

Thanks guys-
Dave
----------------------------------------------------------------------
Just because I'm a Global Moderator, don't assume that I know anything !

Dave->    ;)

Offline Tweakie.CNC

*
  • *
  •  8,081 8,081
  • Super Kitty
    • View Profile
    • Tweakie.CNC
Re: PWM Mach Settings
« Reply #6 on: May 16, 2010, 12:03:27 PM »
Mach screenshots look OK to me, at least that is exactly what I would do. (have you tried minor tweaking like changing the PWM base to 100 etc.?)

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.

Offline budman68

*
  • *
  •  2,360 2,360
    • View Profile
Re: PWM Mach Settings
« Reply #7 on: May 16, 2010, 12:26:53 PM »
I have not as of yet as that was part of my original question. I have no idea what half the settings mean. I've looked at the manual but not much help to me. I didn't want to go randomly switching things around as not to screw something up on my main machine PC. I thought maybe there would be an obvious setting to change but I can't see it.

Thanks,
Dave
----------------------------------------------------------------------
Just because I'm a Global Moderator, don't assume that I know anything !

Dave->    ;)

Offline Tweakie.CNC

*
  • *
  •  8,081 8,081
  • Super Kitty
    • View Profile
    • Tweakie.CNC
Re: PWM Mach Settings
« Reply #8 on: May 16, 2010, 12:55:12 PM »
Hi Dave,

I didn't get reliable results here (just a bench test) with a base frequency of 50 but at 100 I was able to change the mark/space ratio of the PWM signal from around 1% to 99% with the spindle speed slider.

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.

Offline budman68

*
  • *
  •  2,360 2,360
    • View Profile
Re: PWM Mach Settings
« Reply #9 on: May 16, 2010, 12:57:35 PM »
Interesting, that's a start, but just as a note, it did work with that setting on the bench so I'd be curious to know what/why that is.

I certainly do appreciate your time and will have a look when I get into the shop tomorrow-  :)

Dave
----------------------------------------------------------------------
Just because I'm a Global Moderator, don't assume that I know anything !

Dave->    ;)