X-axis randomly latching to other MPG axis

I need help, before I kill something...

I've scrapped 2 parts out recently and shattered an end mill. At what appear to be completely random intervals my X-axis will latch onto whatever axis is moving and move by the same amount. As you can imagine this doesn't do an end mill any good when you're buried 3/8" deep in a piece of steel.

Odd part is, this is only happening when I use the MPG to move an axis that is *not* the X-axis, it doesn't happen if I use the buttons on the AXIS interface. I've opened up the HAL monitor and can clearly see that the pin for the X-axis MPG selector switch is not switched on. And it goes away if I reboot, but then comes back at random. So I don't think that this is a wiring issue.

The only thing that has changed recently is the addition of a SPINX1 and VFD to control spindle speed, but it operated fine for about a month with those two installed and working without doing this.

Any ideas what is going on? I've attached my machine's files.

Also, how do you keep the update manager from popping up and causing a realtime delay? It hasn't caused a scrapped part or broken tool yet but I think it could and would rather it not.

I should add, this happens regardless of whether or not the VFD/spindle is running, and has happened before I've even turned the VFD on.

you are picking up noise from the VFD and other parts , have you fitted a filter to the vfd ? , are your low voltage wires i.e switches in sheilded cables
all this will help , this is quite a common problem , try also to keep mains and VFD wires seperated from low voltage ones

check for any loose wires or broken ones , and that all connections are tight and sound
yes it could be a software issue , but if you have not updated any files lately , i would discount that
and look more along the lines of an intermittent connector or cable

andypugh wrote:

greenbuggy wrote:

At what appear to be completely random intervals my X-axis will latch onto whatever axis is moving and move by the same amount.

Is this in "auto" mode, ie running G-code, or when jogging with the MPG?

Its only happened while jogging with the MPG, with or without the VFD/Spindle running

andypugh wrote:

greenbuggy wrote:

Its only happened while jogging with the MPG, with or without the VFD/Spindle running

Do you have a hardware switch to select the active axis for jogging?

If so, are the un-selected inputs grounded or left floating?

The un-selected inputs are left floating but go thru an optoisolator (CNC4PC C22) before making it to the parallel port. In the HAL Monitor I'm not seeing any axis selection pins turned on besides the one I'm trying to move (Y or Z the couple of times this has happened)