CTEK (VMC), OAK, DELTA A2, ECMA motors

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CharlesRohland
Posts: 2
Joined: Wed Apr 20, 2022 2:24 am
Acorn CNC Controller: No
Allin1DC CNC Controller: No
Oak CNC controller: Yes
MPU11 & GPIO4D -w/ 3rd Party Drives: No
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No
CNC Control System Serial Number: A901131
Contact:

CTEK (VMC), OAK, DELTA A2, ECMA motors

Post by CharlesRohland »

Hi All,

Our project is a CTEK KM80D VMC, made in Taiwan, it has 5mm pitch ball screws directly driven by 1KW motors on the three axes. Z has a counter weight. Spindle is 7.5 HP 8000 rpm driven by RICH VFD. Machine came without servo drives and controller. See link in signature for images and build progress

I have bought the OAK board, and was going to originally run DMM DYN4 servo drives and signal converters to try and re-use the servo motors. The plan now is to run Delta A2 1.5KW drives and motors (not purchased yet)

Three questions for now.

1. Does anyone have a trusted source for Delta components in China? Preferably someone they have used?
2. Delta A2 drives and motors come in 200 or 400 volts, what are the pros and cons either way?
3. The standard schematics sent with Oak show VFD connected direct to live and not through a contactor, original machine was through a contactor, is that a better route?

Thanks
Charles
Build - Ctek VMC (Taiwan) + OAK + DELTA A2 Drives and servos + RICH VFD

https://photos.app.goo.gl/CWA42HbquUC5iu4t7
cncsnw
Posts: 2699
Joined: Wed Mar 24, 2010 5:48 pm

Re: CTEK (VMC), OAK, DELTA A2, ECMA motors

Post by cncsnw »

1) No idea.
2) You use 400V servos if your control cabinet (machine) is going to run on 400V service (or 480V in North America). You use 200V servos if your system is going to run on 230V (or 240V or 208V in North America, or 220V in Asia). If you have a choice -- i.e. if you have both 230V and 400V available in your shop -- it is a coin toss for a machine the size of yours. If you were retrofitting a machine with 4kW servos and a 25HP spindle, then the smaller wire gauge that 400V allows is a real benefit. Wrestling 6-4 servo power cables into place is not much fun.
3) It is long-standing Centroid tradition to maintain line power to the spindle drive, and only interrupt the run command in case of fault or emergency stop. However, it would be better practice to have a more reliable emergency stopping method. Newer drives often have a "safe torque off" or safety inhibit, that allows you to reliably prevent operation by interrupting a low-voltage control circuit. Absent such a feature, the only way to be sure the spindle cannot get power is to interrupt line power using a contactor.
CharlesRohland
Posts: 2
Joined: Wed Apr 20, 2022 2:24 am
Acorn CNC Controller: No
Allin1DC CNC Controller: No
Oak CNC controller: Yes
MPU11 & GPIO4D -w/ 3rd Party Drives: No
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No
CNC Control System Serial Number: A901131
Contact:

Re: CTEK (VMC), OAK, DELTA A2, ECMA motors

Post by CharlesRohland »

@cncsnw thanks for engaging, much appreciated!

We run 220V and 380V in South Africa, looks like 220V single phase for the servo drives is ample.

I have spare contactors so I will run one on the VFD, I assume I can wire the VFD contactor coil through one of the servo drive contactor NC contacts?
Build - Ctek VMC (Taiwan) + OAK + DELTA A2 Drives and servos + RICH VFD

https://photos.app.goo.gl/CWA42HbquUC5iu4t7
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