Epilog Mini 24 Y-axis motor failure?

[Oleg Mikhailik]

Hi everyone!

Hasn't been two weeks since my mainboard replacement, but low and behold Murphy's law strikes again!
This time it's the Y-axis. Yesterday a vector cutting job stopped halfway through in the middle of the table and the gantry siezed - we got a X/Y DISABLED message on the display. Restarted the laser, and as the head returned to base, the movement along Y axxis was very jittery, in jumps, with significant vibration.

We checked Everything we could - belts, pulleys, axis rails - nothing comes to mind. In fact, when I move the gantry by hand, even if it's by pulling the belt at the motor - it moves in a smooth manner. But when the motor does the job - it can barely clear half the table before stopping and triggering the XY error.

Curiously enough I found a video online of some other unfortunate soul having the same exact problem:
https://www.youtube.com/watch?v=lkgTX9PQLHY

So: anyone else had this?
Is my Y-motor shot? or is there perhaps a place I may have missed trying to clean it?

Thanks for any advice!!

Oleg

[Kev Williams]

you may have a bad wire running to the stepper, either the wire itself being compromised, or a bad connection at the plugs. I've had this happen on two different machines over the years--

[Oleg Mikhailik]

Thanks Kev,
Any idea how to diagnose this? or to find which wire is indeed the bad one?

[Kev Williams]

My bad wires made it easy for me,
first was this wire-- Triumph just soldered and covered extra wires to the short wires that came with the stepper motors they used on the machine, that would extend to the stepper controller... the soldered connections were within the 'drag chain, and the erratic action would start once the gantry got to below 17" down from top zero, which is the point the soldered connection rolled up into the chain...
chain3.jpg
--this is where the connections would bend, and eventually broke this ground wire-
brokenwire.jpg
-- this my Chinese Triumph...
But "good" machines aren't immune, had the same thing happen to my Gravograph LS900,
where this green wired rubbed on the cabinet, while in the chain, when gantry moved,
evidently the chain didn't keep the wires fully protected. One day the X axis started acting
bonkers. The machine made it easy to find the problem, this bare spot was arcing against
the cabinet, which made it very easy to find the problem! This what it looked like after I cut
open the chain and found this--
9wire2.jpg

My repair was to add a short section of wire, to which I soldered both broken ends to
and covered the soldered joints with heat shrink, taped them, then covered the chain
best I could--
9wire5.jpg
This was several years ago, it's been fine ever since!

And for good measure, fiber lasers can suffer the same issues--
My first fiber started engraving just plain goofy at times, check
out how "STATES" engraved in this upper photo, where "TES"
moved up and the underline grew a bend and even overlapped
the "S"--
f1.jpg
^^ this pic shows one that engraved correctly--

--and this pic, the same thing happened while deep engraving
an injection mold, although I got lucky as the outta-whack 'shadowed
engraving was short lived, and didn't show up in the molded item...
mold6.jpg
--the problem was an iffy soldered wire connection on the connector from the galvo scanhead that plugged into the controller. I re-soldered it and that took care of it (but to Triumph's credit they insisted on replacing the scanhead on warranty)...

I can think of at least of 4 my rotary tool machines that have had stepper issues, 3 were wire connection issues, and the 4th machine was around 30 years old the steppers were just plain worn out!

If you're handy with disconnecting connector plugs and such, I'd recommend picking up a can of CRC electronics spray cleaner,
crccleanr.jpg
unplug the machine while it's on (so everything powers down), open up the machine and track down every electrical connector you can find, unplug each one and liberally spray both ends and re-plug them. With luck just doing this will cure your problem; it has for me several times! If it doesn't, then at least you'll know you'll need to look further, and that all of your connections have been refreshed!