Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: wlarry on November 24, 2008, 10:12:18 AM

Title: X axis driving down without command
Post by: wlarry on November 24, 2008, 10:12:18 AM

I am running a plasma setup with THC-300.  Had the system working perfectly for several months then problems.  When the torch moves to the first cut, it senses the plate surface, and begins the cut. As the unit is cutting, the z axis is driving down.  If the THC is ON, it tries to counter the effect but by the second or third cut, the z has gone 6" and bottomed out. It does this regardless if the THC being on of off.  It appears as though the z axis is loosing track of its zero position. I can zero it at the start of a cut and by the time it had made 2-3 cuts, the z reading is out as far a 1.5".

Any thoughts ?

Title: Re: X axis driving down without command
Post by: bowber on November 24, 2008, 11:35:15 AM

I've had this recently and it turned out to be that old friend "electrical noise".

I'd been fiddling in my control box to replace a broken 4th axis controller and I'd pushed some of the wires around, I'd them been doing some cuts and the Z would climb or drop with no commands, messed up a small jobs before I noticed, anyway I checked in the control box and the Z step and direction wires were crossing some others so I straightened it all out and everything has been fine since.