Y axis problem

[Erin Keck]

Hello, I have a Full Spectrum 90 Watt Pro16X24 Laser Machine. I just started having an issue yesterday where it started jumping around on the Y axis. Even when just homing the laser head it wants to continue past where the further most area is and grinds. During a job it may cut fine for awhile but then just totally may skip about an inch or so up on the Y axis. Does anyone have any ideas? Thanks so much in advance.

[Kev Williams]

Been thru this 3 times on 2 machines, you may have a nearly-broken X-stepper wire in the 'drag chain', they go bad at a solder joint. Usually works okay while the wires lay flat, but once the bad spot gets rolled-up into the chain, then the wire's connection goes away and axis chaos ensues. The reason it goes past home and grinds is because while it's jumping, it ends up losing steps-- but the controller doesn't know that, it just knows how far it's supposed to go, and it'll keep feeding the stepper pulses until it thinks it's home even if it's locked up against the wall.

Test the thing in the dark,run a job with the laser off and watch the Y drag chain, you may get visible sparks--