How Would You Upgrade An Old Ox CNC Build Into A Serious Machine?

[Clive S]

surprised me when I read the manual and it clearly says to NOT use a contactor or it could damage the VFD. I’d watched people on YouTube use contactors in their build and would have made a big mistake if I hadn’t looked at the manual.

What you basically must NOT do is put any form of switch between the VFD and the three motor cables going to the spindle or unplug the spindle with the VFD running.

If you do you might hear a big bang.

[Kitwn]

What you basically must NOT do is put any form of switch between the VFD and the three motor cables going to the spindle or unplug the spindle with the VFD running.

If you do you might hear a big bang.

Double up on that several times over!! NOTHING should come between the VFD and the spindle. Only ever use the spindle ON/OFF control wiring to stop the spindle if you ever want it to start again. I wouldn't even cut the mains input to the VFD with the spindle running, though that might be my clinical anxiety kicking in

Kit

[JAZZCNC]

What you basically must NOT do is put any form of switch between the VFD and the three motor cables going to the spindle or unplug the spindle with the VFD running.

If you do you might hear a big bang.

Double up on that several times over!! NOTHING should come between the VFD and the spindle. Only ever use the spindle ON/OFF control wiring to stop the spindle if you ever want it to start again. I wouldn't even cut the mains input to the VFD with the spindle running, though that might be my clinical anxiety kicking in

Kit

While this excellent and sound advice, It isn't exactly correct.? . . . It's true that you shouldn't control the spindle ON/OFF with a Contactor between VFD and Spindle or use anything that will interrupt the connection while running, however, you can safely have a contactor between them provide it is not switched while the VFD is running.
I've done this before to control multiple spindles with single VFD but there must be safety involved and interlocks checking the spindle as stopped spinning and the RUN command isn't active before allowing it to happen.

This said the advice above is good.

[NeoMorph]

What you basically must NOT do is put any form of switch between the VFD and the three motor cables going to the spindle or unplug the spindle with the VFD running.

If you do you might hear a big bang.

Wouldn’t that turn the spindle into a generator with nowhere to send the juice? Plus does the power run a cooling fan?

One thing I didn’t specify in my order was a breaking resisistor. Do I need one?

[JAZZCNC]

Plus does the power run a cooling fan?

One thing I didn’t specify in my order was a breaking resisistor. Do I need one?

The only fan is inside the VFD to cool the electronics, the spindle doesn't have any fans. Some Vfd's the fan only comes on when VFD is running whatever is connected, some come on at power-up and stay on. The huanyang VFD is on all the time. (That said some Huanyang models do have load driven fans but can't remember the model #)

Only need a braking resistor if you want to use DC braking to stop heavier loads. For the most part, provided you don't have the Spindle de-acceleration time too short and not using heavy or wide tooling then won't need a resistor.

[NeoMorph]

The only fan is inside the VFD to cool the electronics, the spindle doesn't have any fans. Some Vfd's the fan only comes on when VFD is running whatever is connected, some come on at power-up and stay on. The huanyang VFD is on all the time. (That said some Huanyang models do have load driven fans but can't remember the model #)

Only need a braking resistor if you want to use DC braking to stop heavier loads. For the most part, provided you don't have the Spindle de-acceleration time too short and not using heavy or wide tooling then won't need a resistor.

Thx for the info.