Need help with cnc retorfit

[tristanlobb]

It's looking like I'm going to buy Clearpath SDSK servos and a centroid ACORN.

Does the centroid acorn support closed loop systems? I know the clearpath has a HLFB on it and I saw a wiring diagram where the HLFB is wired up to the acorn.

Do I even need a close loop? I've seen retrofits on bridgeports where they use 1200 oz-in stepper motors so they don't loose position but I'd rather just have a close loop system. I can't afford much but I'd rather do it once correctly rather than coming back multiple times trouble shooting and adding new stuff. Thanks yall

Links-

X,Y servo https://www.teknic.com/model-info/CPM-SDSK-3421P-ELS/
Z Servo https://www.teknic.com/model-info/CPM-SDSK-3411P-ELS/
Centroid Acorn Acorn CNC controller, Step and Direction 4 axis CNC Control board with ethernet communication.DIY CNC kit

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[Jim Dawson]

The ClearPath servos close the loop at the drive (in the motor). There is no encoder output from the ClearPath drives. The Acorn does not support closing the loop at the controller as far as I understand.

I have used the ClearPath servos on a Multicam router retrofit and was pleased with the result.

[tristanlobb]

Thanks for your insite Jim,
Does this mean I will not lose position in rapid moves or heavy cuts? What kind of accuracy do I think I'll actually be able to maintain?

[Jim Dawson]

If you go with the SDHP motors, they come stock with the ''enhanced resolution'' option so I would expect that your accuracy would be at least as good as the original servos. Because they are a closed loop is really no way to lose steps with these motors, but like any motor, it is possible to stall them on overload. If that occurs, they will send a fault signal and shut down. You need to set up your system to handle any faults, it should trigger a soft e-stop. This would be a pretty rare condition, generally associated with operator error.