Centroid Community CNC Support Forum

I know you said not to Marty but I couldn't resist, I bought a DMM servo for my acorn retrofit spindle motor. The schematic I received from DMM says to wire it as a spindle drive I'll connect into H5 and H8, except there is no H5 on my board. I'm assuming from this schematic from DMM and current schematics from the Centroid webpage about dyn4s that before the included relay module was a thing the H5 terminal area was located there?

It appears that I'll have to wire my dyn4 drive into H3 where I would wire up a 4th axis then just tell the acorn wizard that's where my spindle motor is located? In the future then because my spindle motor will be wired to the H3 location, if I build a 4th axis I'll need an ether1616 expansion board to accomplish that?

When it comes to using DYN4 and their AC Servo as a spindle motor, you are on your own. I have attached what I have that came from DMM. It may be outdated.
If you get it going and tuned properly, I would like to see a video of the machine rigid tapping and peck rigid tapping....
Good luck!
Marty

Thanks Marty, ya that was the diagram I was looking at. Can't be that difficult to get wired if other guys have done it I can probably find out how to.

I'll post up a wireing diagram when I do.

Dear Setlab,
I too have gone the dyn4 rout for a spindle motor. I have mine wired to IN5 for spindle OK signal. Spindle enable to relay 1 and direction to relay 2.
I have the analog signal on H8. I set relay 1 as "VFD enable" and relay 2 as "VFD direction" in the acorn wizard. you will have to follow the wiring diagrams in the DMM manual to get them to work. wire circuit "A" for relay 1 and wire circuit "C" for relay 2. An issue i ran into is that the acorn PLC disables the VFD enable signal immediately upon spindle stop or M5 commands. Dyn4 does not like this and will throw an overvolt alarm. CNCSNW was kind enough to show me the way to correct this in the PLC code. (Solved) acorn PLC programming change. For dyn4 servo spindle control. is that thread.
all the best
Sean

Thanks, Sean! I'll give that some thought. After I actually read the DYN4 manual the wiring process sounded a little less risky. My game plan is kinda what you mentioned, one circuit with a 5v supply for forward and reverse and one circuit with a 24v supply for the enable using the diagrams in the manual (if I remember right, it's been a few weeks since I thought about it). I still haven't wired up the spindle though, Christmas projects have taken over my shop time at the moment. My hopes are to get all wiring done before the new year.

Hey Setlab,
Were you able to successfully complete this retrofit? I'm just getting into this upgrade and wanted to make sure I see some wins before I tear into my cnc.
Couple of Questions:
1) are you using the dmm servo's encoder?
2) If I have an external breaking resistor do I need to make the changes to the PLC?

Well..... I got busy and my project has just set for awhile lol. Coming here to motivate myself and refresh my memory on troubleshooting details again now. You may have seen it already but there was a couple topics about the dmm/dyn4 servo combo troubleshooting use as a spindle drive, I think these were all spacedmanspiff's treads if you want to search for them. If memory serves they posted a workaround to get this combo running smoothly, I forget what now but something in acorn didn't like sudden speed changes or maybe it was speed stops in that combo. It sounded like the issue was fully resolved and there was a lot of detail in those topics too.

But to your questions, I initially plan to use the servo's encoder even though I know it won't represent the spindle rpm. It will be more of a learning side project. My final plan is to hook a direct drive encoder to the spindle with a 1:1 timing belt. No idea about your second question though, I would say try it and find out?