Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: ostie01 on June 18, 2009, 01:46:36 AM

Title: Water cooled spindle motor safety
Post by: ostie01 on June 18, 2009, 01:46:36 AM
Hi, I'm about hooking up my Water cooled spindle motor and I have some concern about safety.

On my old motor, I had a safety switch in series with the motor so when I had a tool change to do, I always disable it with the switch, did not want to rely on Mach3 only.

But with the new motor which have a VFD, as per the manual, nothing can be connected between the VFD and motor.

I want Mach3 to control the on and off of the spindle and when everything is working OK, then I want mach3 to Control RPM too.

But not sure about Mach3 for safety, afraid something happen when my hand are near the spindle in a tool change.

Any advice, Jeff

Title: Re: Water cooled spindle motor safety
Post by: Hood on June 18, 2009, 02:56:47 AM
You could cut the power to the VFD itself but obviously the capacitors in the VFD would take a while to discharge. There may be an enable signal for the VFD which you could use with an external button, this will still rely on the VFD working correctly internally to make sure it does not allow the spindle to start but should be very reliable.
Hood
Title: Re: Water cooled spindle motor safety
Post by: ostie01 on June 18, 2009, 03:39:22 AM
Hi Hood, as usual, always an answer for everything.

Thanks for your support, will see if this can apply to my VFD.

Again, Thanks
Title: Re: Water cooled spindle motor safety
Post by: vmax549 on June 18, 2009, 03:03:30 PM
ONly 2 things I have seen that apply .  A spindle brake to lock down the spindle or a spindle index that is basically a slot and a pin to lock the spindle. IF something went wrong the VFD will trip off.

One setup I saw was simply a wrench in a slot that slid over to engage the spindle flats and it also doubled as the wrench to lossen the spindle nut.

Just a thought, (;-) TP
Title: Re: Water cooled spindle motor safety
Post by: macona on June 21, 2009, 03:53:04 AM
As long as you are not stopping the spindle by using the FWD or REV inputs on the VFD and no just turning the spindle control voltage down to 0 you should never have an issue with the spindle starting during a tool change. Not only would mach have activate the output line controlling the direction but it would also have to output either PWM or Step signal to activate the analog board controlling the VFD.

On my mill I have separate relays for FWD and REV and they are interlocked so they can not be operated at the same time. I have never had an issue with the spindle moving even the slightest.
Title: Re: Water cooled spindle motor safety
Post by: jimpinder on June 22, 2009, 03:36:55 AM
Following on from the last post, you could try having a switch which put a signal on the Forward and Reverse switches of the  VFD. This, on my Omron, shows up as a fault, immediately, and the spindle is dead. As soon as the signals are removed, and replaced by only a Forward OR Reverse the spindle starts again
Title: Re: Water cooled spindle motor safety
Post by: ostie01 on June 22, 2009, 04:47:11 AM
Good idea, will give it a try, Jeff