View Full Version : VHD Mounting problem

24-11-2012, 10:04 PM
Hi wonder if anyone can help. I bought a CNC router from a chap a while ago now (about 5 months ago). Anyway have just started to set it up...when I bought it the guy advised me the VFD should be mounted as far away from the router as possible as it causes interference. Anyway mounted it about 7ft away from the mill which isn't as far away as he had it but due to the cable length/run around my workshop walls this is as physically far as I can get it. OK now if I turn on the mill without the spindle/VHD on everything works fine...however turn on the VFD and things start going awry...the stepper motors start making a grinding noise and creep the whole rig around in small steps. So is this correct is the VFD causing interference and if so I need to move it further away, which means buying a new length of cable...so which cable do I buy, is this any use. Many Thanks in advance.
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24-11-2012, 10:10 PM
I'm suprised you're getting that amount of interference from an inverter, what make, size, spec, of inverter is it. I've run inverters in the same enclosure as the control electronics with no interference whatsoever, in fact the mains lead tends to be the main offender.

24-11-2012, 10:12 PM
Its 1.5 Kw ...the cable is supposed to be shielded...but noticed some electrical tape may be covering a joint/slice about 5ft from the router.


24-11-2012, 10:23 PM
i quite often put an inverter, stepper drivers, power supply, relays, bob, isolated 0-10v board, in the same 600 x 400mm case, with no problems at all.

24-11-2012, 10:31 PM
The cable I have connected is about 15ft ...but due to the way it has to route from the machine to the VFD the VFD is about 8ft away from the control box for the steppers ....very small filter on the incoming. Do you think the problem is the cable?

24-11-2012, 11:01 PM
what stepper drivers are you using

24-11-2012, 11:29 PM
if people are saying it is fine running them close, then you either have older spec to them or you have a dodgy component somewhere and the seller knew this but just blamed it on keeping the vfd distant from the rest to cover his back

25-11-2012, 12:11 AM
Hi spec as I have it is
NEMA23 motors 22kg
micro stepper for 400 to 25000 spt
4.2A Industrial Grade micro stepper drive

Is this the info ?

Guy did show me it working before collection..and it did cut some nice stuff well enough in fairness....just this is the first time it moved in 5 months

25-11-2012, 10:29 AM
many thanks for that guys..especially Clanzer

To belt and brace it I will replace the cable between the VFD and the spindle and fit some more EMI's whilst carefully planing the route ...question though...is this the correct cable required and what is the 4 pin connector plug called that connects to the spindle (looks like xlr )...will try and source a new one for a nice new solder fix.(if anyone knows from were that would help) also is there any limit to emi's fitted...have a few here so shall I stick em on adjacent equipment wires
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If this is the correct cable I understand the drain wire should be earthed at the VFM end only..yes?

Cheers again..very grateful