Z axis drift during X-axis motion...

[Chet]

I'm using Mach3 with a computer running Windows XP and a HobbyCNC driver board.
I've noticed that the Z-axis motor will rotate slightly during runs on the X-axis only.
It is stable on Y-axis runs.
I'd love to get rid of the drift...
And, yes, I've already added the extra capacitors to the cables going into the HobbyCNC board to ground out cross-talk.
So I'm open to new suggestions...
Chet

[Hood]

Either electrical noise, possibly even on the output side of the drives or you have duplicated pins in Mach.
If you attach your xml I can check your config.
Hood

[Chet]

Okay, which of the reply icons would I use to attach that file???
On regular e-mail I'd be confident, but I'm not seeing what I'm looking for in the icon list.
Of course it could be there, I just don't recognize it...
Chet

[Hood]

On the reply page you will see the additional options button, you can use that to attach your xml. You may need to rename it first though if it has a standard name as the forum only accepts a file name once.
Hood

[Chet]

Okay, let's see if I'm uploading the file correctly...
Hope you find something useful...
Chet

[Hood]

Dont see any problems of pin duplication in your config so it is likely that it is noise getting into the wiring.
Hood

[Chet]

Just performed an interesting test...
There is NO drifting of the Z-axis when I manually move the carriage along the X-axis with the keyboard commands.
It only occurs when the X-axis is moving during a program execution.
What does that imply??

[Hood]

Seems strange unless your code is calling a Z axis move. What if you MDI a X axis move?

Hood

[Chet]

MDI????
If this refers to moving the X-axis from the keyboard, I can do that without Z-axis drift.

[Hood]

MDI is manual Data Input
When you said you were moving via keyboard I presumed you were meaning jogging but you are meaning via entering G Code commands in MDI line?

If you are then I cant see how that would be any different than from Mach running code from a file.

When you start Mach and hit the Reset button for the first time do you get any messages?
Hood