Centroid Community CNC Support Forum

Hello Marty & All,

After a busy summer I am wanting to get back to this project.

Now that I know what is needed in order to re-use the existing the spindle drive and motor I am focusing on the servo motors:

As listed earlier in this thread the machine currently has C23-L50-W20 servo motors which appear to be in good condition and I was/am hoping to re-use.

https://www.moog.com/content/dam/moog/l ... series.pdf

They are rated at:
360oz-in peak torque
2150RPM rated speed
30.1oz-in rated torque
3.5amps rated current
42oz-in continuous stall torque

Looking at another retrofit thread on the IndustryArena forums I know these servo motors can be re-used with new encoders. If I stick with these motors I will use the AMT102-V encoders:

https://www.digikey.com/product-detail/ ... ransducers

Are servo motors that much better than steppers?

I am concerned about the initial set-up and PID tuning process of the G320X and servo motors. I do not own a oscilloscope and I have never used one.

Any advise/education on this is appreciated.

Are they NEMA 23 or 34 motors?
I personally would replace the axis motors. You might look at closed loop hybrid stepper motors and drives from CNC4PC.com or automationtechnologies.com is you are in the US. CNC4PC sells genuine Leadshine drives and motors.

They are NEMA 23, I will take a look at the websites you listed however I would like to have a better understanding of Servo vs. Stepper motors before I pull these ones of the machine.

Big picture I don't want to loose any of the machines capability by going to steppers.

Closed loop steppers have a encoder feedback to it's drive, effectively closing the loop. So far, for me anyway, I've used them right out of the box.

If you are intent on using your DC Brush servos, you may have to replace their encoders to be compatible with the G320x. You will have to tune them. Search YouTube for G320x to see what is involved. I stay away from doing what you propose. Newer technology, not a lot more money. Motors and drives engineered to work together. I'm not saying it can't be done. What is your pain/time threshold?

You do need to replace the existing servos with motors at least equal to or a little greater torque rated motors.

martyscncgarage wrote: ↑Sun Oct 20, 2019 9:07 pm Closed loop steppers have a encoder feedback to it's drive, effectively closing the loop. So far, for me anyway, I've used them right out of the box.

If you are intent on using your DC Brush servos, you may have to replace their encoders to be compatible with the G320x. You will have to tune them. Search YouTube for G320x to see what is involved. I stay away from doing what you propose. Newer technology, not a lot more money. Motors and drives engineered to work together. I'm not saying it can't be done. What is your pain/time threshold?

You do need to replace the existing servos with motors at least equal to or a little greater torque rated motors.

Hi Marty,

I did a lot of research and reading last night regarding servos and steppers. I am starting to come around to your way of thinking, and I am now leaning towards replacing the old servo's with new hybrid steppers and drivers. Like you said not a lot more money and I would know everything would be new and engineered to work together.

One thing I am struggling with; I know I need to purchase steppers with equal or greater torque. Which torque value should I be comparing? Peak torque or rated torque? Also- I see a lot of "holding torque" is this the same thing as "peak torque ?

Rated torque is usable power. I would put more weight on that.
Post you current motor ratings.
Marty

C23-L50-W20 servo motors

https://www.moog.com/content/dam/moog/l ... series.pdf

They are rated at:
360oz-in peak torque
2150RPM rated speed
30.1oz-in rated torque
3.5amps rated current
42oz-in continuous stall torque

I suggest you call CNC4PC and ask them for Leadshine Hybrid motors and drives with cables. Give them the specs. Let them assemble the drive/motors/cables for you and quote you a price.

Your other alternative is to look at Teknic SDSK Brushless servos. The drive is built into the motor.
https://www.teknic.com/products/clearpa ... vo-motors/

Hello All,

Its been quite some time however I have made some great progress with my conversion as time allows.

I have a general question regarding mains power coming into my machine:

I currently have four devices which require 120V AC Power:
-Acorn Board Power Supply
-Stepper Motor Power Supply
-Spindle Control Board
-KBSI-240D Signal Isolation Board

Currently incoming power is wired to a DIN rail terminal strip and then each device is wired AC power from there.

I currently have no main power switch for the machine, meaning the only way to turn it on or off would be to unplug it from the wall socket. Less than ideal in my opinion.

Can anyone provide any suggestions on how to install a main power switch?

Can I run the main power through an AC relay and have this wired to a switch I can access somewhere on the front of the machine? (I believe this is how it was originally wired however I did not fully understand the wiring.)

So you are plugged into a 120vac 15a circuit?
You can use an on/off switch (toggle or disconnect) rated for the load.
You can use an on/off switch controlling a contactor.
You can use a breaker sized appropriately.
Did you fuse the control?