GOTO Zero goes to incorrect coordinate for X, yet Y and Z are correct... HELP!

[kenatic]

I just got one of the those CNCEST 6040engravers off ebay. I added a wireless pendant. I'm actually fairly impressed with the machine given the price. 1.5kw water cooled spindle etc.
Of course now I need to use it for a critical project -- I just got it setup two days ago with Mach3.

I've used Mach3 on other machines that I've retro-fitted. But this problem has me stumped.

I calibrated the machine's "steps per unit" setting (factory 320=x, 320=y 400=z) using the tool in the setting tab. Came out close to factory. When I test movement accuracy on all axis it's very good. So it seems the steps are correct. So far so good. I set work-piece zero for the current tool, move off a ways and hot GOTO Zero and the Y & Z go to the right spot, but X is off to the left (negative) a little -- and it gets worse each time, but Y and Z are perfect.

Setup:
I set the home, work offsets and tool offsets correctly. Then when I edge locate 0,0 and set tool height 5 (I've tried 1 through 4 too) such that 0,0,0 is the upper left corner of the workpiece. Then I move off to say 100,200,300, and hit GOTO ZERO (not in machine coordinates) with tool 5 a 1.7mm endmill, (or any tool), the machine moved to the Z and Y zero position correctly. But the X is off by -0.7mm... which sounds like 1/2 of a the tool diameter. However, if I repeat the process of "move off zero" and "goto zero", the X position is even further off between -0.4 and -0.8mm each time and it grows.

So I go back and calibrate the X steps per unit. Test it with the dial indicator afterwards and it's perfect, almost no backlash etc. But GOTO Zero still puts X in the wrong position, and Y and Z are fine. The more times I push GOTO Zero the more X moves off. Moving X to a new location and mearsuing the amount of movement is perfect (enough) in all three axis.

So why isn't X going to 0 when Y and Z do? And why does it get progressively worse.

What is that can cause just the X to be off when moving to zero only? Could it be related to cutter compensation?

I verified all the factory settings in the controller are correct.

I had no such issues with the Bridgeport Discovery retrofit I did two years ago. I do not think it's a H/W problem. Could the wireless pendant plug-in/macros do this? I'm using the screen's "GOTO ZERO" button, not the pendant.

Thanks in advance!
Scott

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[kenatic]

RESOLVED! So I did some testing.... using the pendant to move position on the Z was also changing the X!!!!!!!

I got the 6 axis SHINA via Amazon. "SHINA New CNC 6 Axis Wireless Mach3 MPG Pendant CNC Handwheel Manual Pulse Generator"
I loaded the standard macros etc and it seemed to work pretty good. But we could not get X to GOTO Zero at the same point every time. Then I finnally noticed that the X moved a little everytime the Z moved!!!!! THe more the Z moved, a little tiny more the X would move! But only with the pendant. Moves with the soft-pendant were fix, as was the G-Code programs I ran.

SHINA REALLY!?!?!?!?! I paid $130 for a true-6 Axis Pendent and was super excited to get it. The last pendant I bought for my huge CNC was $1200 from the OEM and it wasn't as nice.

Anyway, I'll look at the macros and see what is going on, or return it to Amazon's seller for a refund.

Arg!