Acorn W/ DMM Servo Spindle Motor on Lathe

[kwkenyon]

Gentleman,

Please find my latest report attached. I have this small lathe with a DMM 750W servo fitted and a DYN4 drive. It is wired up with the Acorn per DMM drawing with encoder attached to Acorn. It works ok, however, MDI commands are not accurate. These are of course based on servo settings in the DMM software. I don't know what setting in Acorn or the DMM software to set for the proper gearing combination. Also, I cannot get the spindle system system to reverse, for example tapping etc. Any help would be helpful. Thanks in advance. Kurt Kenyon

[martyscncgarage]

Gentleman,

Please find my latest report attached. I have this small lathe with a DMM 750W servo fitted and a DYN4 drive. It is wired up with the Acorn per DMM drawing with encoder attached to Acorn. It works ok, however, MDI commands are not accurate. These are of course based on servo settings in the DMM software. I don't know what setting in Acorn or the DMM software to set for the proper gearing combination. Also, I cannot get the spindle system system to reverse, for example tapping etc. Any help would be helpful. Thanks in advance. Kurt Kenyon

Consult DMM. There are specific settings you need to change in their DMMDRV software.

[kwkenyon]

Thanks, I'll let you all know the out come.

[martyscncgarage]

Thanks, I'll let you all know the out come.

Great!
Once you have it all setup, please share how you set it up and a video clip of it running. That would be helpful for other users interested.

Marty

[kwkenyon]

No problem, got it going. I'll make a video and write a post this weekend.

[martyscncgarage]

No problem, got it going. I'll make a video and write a post this weekend.

Right on. All the steps and video description will help others. Thanks alot!
Marty

[kwkenyon]

Gentleman,

I will post all about this spindle servo soon with pictures and video. Its working great except commands from Acorn MDI for example: M3 S500 turn on to 440 RPM, subsequent commands S600 to 540 RPM and so forth. I'm satisfied its always 60 RPM low. But why? Is there a way to tweak Acorn analog (my board ca. 0.2V-10.2V, maybe the 0.2V?) internally up 60 RPM across the scale?? If anyone has an idea I welcome it. Thanks. Kurt

[martyscncgarage]

Gentleman,

I will post all about this spindle servo soon with pictures and video. Its working great except commands from Acorn MDI for example: M3 S500 turn on to 440 RPM, subsequent commands S600 to 540 RPM and so forth. I'm satisfied its always 60 RPM low. But why? Is there a way to tweak Acorn analog (my board ca. 0.2V-10.2V, maybe the 0.2V?) internally up 60 RPM across the scale?? If anyone has an idea I welcome it. Thanks. Kurt

Waiting on you kwkenyon.

My guess is you have to tweak the upper RPM in DMMDRV....

Marty

[kwkenyon]

Still working with DMM on this issue. When its finished I'll post all about this DMM servo as a spindle motor. Depending on where the MAX SPEED is set causes spindle to rotate, or not on power up. For example: Max Speed set to 50, servo does not rotate on power up. However, all "M3/M4 S" calls are exactly 50 RPM low, across the range. Max Speed set to 1, spindle turns 50 RPM on power up, However, all M3/M4 S calls are right on the money?

[martyscncgarage]

This is why I prefer to stick with 3 phase motors, VFD and a line driver encoder.

I'm in the same boat. Though am trying to test both position AND spindle operation. I'm about to give this up....I just don't have the time and have spent far too much time on the project already......

I am interested to hear how you make out, IF you make out and the spindle operates satisfactory.

Marty