Centroid Community CNC Support Forum

Since the motors are not a drop in replacement for the Baldor motors I am working on a mounting plate. I also need to determine if the pulley will align with the one on the ballscrews. Attached is a concept.

Finding pulleys for the new DMM motors is becoming a problem I found the 12 Tooth (12L075) but the 15L075 for the Y axis has been difficult. Both axes have a 1:2 ratio, which is convenient, but would a 16/30 combo work? I think I have enough adjustment for the tensioning belt and adding an extra tooth to the motor should provide some extra grunt. The turns ratio will take care of correcting the motion.

Any ratio around 1:2 will work fine. I personaly prefer ratios that are prime numbers. With integral ratios, the same tooth on the belt, hits the same tooth on the sprockets every 1,2,3...N revolutions. This can cause harmonics and repeatable position errors. Using a prime ratio results in any individual belt tooth always contacting a different pulley tooth on every revolution.

For instance on my lathe Z, I have a 44:22 ratio (1.2222222) and on X I have 38:26 ratio.

lavrgs wrote: ↑Sun May 16, 2021 5:12 pm I believe what I have is now wired correctly and only has one software (?) Issue.
I wrote a program to spin the motors and wanted to test the E-Stop. It stopped everything , however when I release the E-Stop it it starts everything. Do I need to set up something to induce a fault, or is this normal?

Ok I have it now...I have a toggle switch jumpered (second E-Stop) into the Acorn E-Stop Signal/COM ports and when I activate that it stops the program or faults as I had expected - Now I just need to wire it to the second set of contacts of the mushroom button.

My bench testing continues..will next try to get the spindle FWD Relay working. I did a quick look and expect to connect to Relay 4 and trigger a Relay for FWD. My initial test had some distractions going on so when I got a fault, I set things back to the way they were. I don't have the spindle connected my intent is just to get the relay working. I will include a REV relay at some time even though I've never run the spindle in reverse. Can rigid tapping be done with just a once around trigger or is an encoder required?

Differential (RS422) quadrature encoder with 1000 lines is recommended. You csnnot use a trigger wheel.

I have had to design some motor mounts for the DMM motors and they will be going out for fab...

in the meantime I would like to bench test one of the motors as a spindle so I can hook up relays for FWD/REV etc. I haven't found much info on doing this but for a start I'd guess I need to communicate to the drive and get it out of servo mode...? Does Centroid have a schematic showing relays used for spindle motor control?

lavrgs wrote: ↑Wed May 19, 2021 10:17 am I have had to design some motor mounts for the DMM motors and they will be going out for fab...

in the meantime I would like to bench test one of the motors as a spindle so I can hook up relays for FWD/REV etc. I haven't found much info on doing this but for a start I'd guess I need to communicate to the drive and get it out of servo mode...? Does Centroid have a schematic showing relays used for spindle motor control?

Did you order the "spindle" servo from DMM that way? Get their info sheet with it?

Did you know DMM sells some NEMA framed motors?
I assume you had all these discussions with DMM prior to purchase?

Marty

It was a bit of a surprise that I had to make mounts...I had convinced myself they were a drop in fit, obviously I missed something. Perhaps its the 1.0 or 1.3 kW motors that would drop in...

The 1.3kW motors are NEMA 42, which bolted directly to my mill.

martyscncgarage wrote: ↑Wed May 19, 2021 10:21 am

Did you order the "spindle" servo from DMM that way? Get their info sheet with it?

Marty

I did not order a "spindle" servo I just wanted to set up the controls and was hoping to use one of the axis motors