Xenetech stepper motor problem

Hi

I have this problem that the Z-axis is not working correctly on my Xenetech 1625. It is not lifting between letters. (Specifically If I try to engrave with cutter up, it stays up, then if I put it on auto then it goes down a few thousands, with each up and down it just goes further down until it hits the table (or material!) but does not go up, also goes to home while dragging through the material)
Also making a huge noise when hitting "mechanical home" or "cancel", only correctly going home by manually lifting the spindle, also sometimes the green light flashes on the pendant and only resumes when spindle is correctly at home.

I have swapped all the cables, pendant, drivers in MPU , tested prox sensor etc. with the same result.

That leaves only one option, the Z stepper motor?, the details on the label only reveals that it is 1.8" (presume thats the size?) and 2.8A ???., the other info brings no results on Google.

Firstly can anyone advise what the problem could be apart from the Z-stepper?
Second can anyone advise the type of motor it is, what I need to specify when looking for a replacement. I am in the UK, so I am looking to purchase it domestically rather than going to Xenetech, (presume it would be cheaper also!). Or better still a model number & mfg./brand.

I have a similar motor but smaller on my Star 912, can I try that, temporarily?, could the power be different and blow it?

Thanks for any help,
David Beenstock
Manchester UK

David, my 1625 is equipped with this stepper motor...........

http://www.ebay.com/itm/Superior-Ele...kAAOSw1h5XP3-0

David

You might reach out to Fred Schwarz here for some advice. http://q1engravers.com/

I've just been thru a complete rash of machine problems lately (which is what I get for saying publicly how dependable they are, lol)...
--and this is just a partial list ;)

3 of those problems have been stepper motor problems, the Z stepper on my 3400 cylinder machine (it would randomly act like it didn't know which way to go), the X stepper on my Chinese Triumph laser (ditto, which I detailed in another thread), and the Z stepper on my old Vanguard 5000 (the stepper would raise or lower a step or two at random while engraving)...

Then there was my LS900 laser just 2 days ago, it started missing steps and running straightlines off circles it was cutting, among other anomolies-

AND a few months ago, my GCC Explorer laser would send the head to engrave but wouldn't engrave anything, followed by complete nothing.

-- I diagnosed and fixed every problem myself:
The 3400 Z stepper problem was traced to a loose spade in a plug connector- easy fix and free--
The Triumph X stepper problem was a broken splice in the stepper wiring- re-spliced it, cost a few bucks for a roll of wire and some heatshrink--
The 5000 Z stepper problem was traced to dirty contacts where the XYZ driver skidboard plugged into the machine- sprayed the contacts and plugs with CRC electronics cleaner, about $5
The LS900 problem was traced to a parallel cable switchbox, the switch contacts were dirty-rotated the switch back & forth a few times, good as new (although I need the right cable and lose the box!)
The GCC problem I figured out was various bad connections when wiggling the cable that connects to the LCD screen when the screen jumped back to life-I pulled and sprayed every plug & receptacle I could find, nary a hiccup since..

So based on my experience..... :)

Nice going Kev, low cost maintenance ....lost time is the only draw back in your case.

Back to David's issue.
Have you checked if lead screw is free of dirt and well lubricated? Also check for loose wires to stepper motor all the way to controller card.
Those motors can take lot's of abuse and still be fully functional so before changing the motor try to eliminate other possibilities.

Hi everyone, Thanks for all your advice.
As I had almost exhausted all other faults (cables, drivers, MPU, APU etc.) I replaced the motor, even though there were many who said that stepper motors are unlikely to fail. Found a very helpful company who managed to match the Xenetech motor, even though there was only a generic label on it.

This is where your further help is needed.
The Z-axis works perfectly!
But the X-axis is now straining and not starting at the correct place! So I need to engrave a dot to locate it's starting point!
However once I have determined where it is to start it engraves perfectly in all axis, also if I press mechanical home/home cancel it goes home correctly, if I press home retain it again engraves perfectly over the previous engraving.

Any advice whats happening now?? I doubt it is the X stepper?

One other answer might solve the mystery, I got detailed info on the wiring of the motor as there were 8 wires and I needed only 4, which wires should be combined and which wires were A-/A+/B-/B+, I just wired them in this order into the junction box and it worked!. There are 24 combinations of matching 4 wires to 4 connectors!!! Is it possible that they can be wired differently, work perfectly but not cause a conflict on the X?

You've got your homework!

David

Quote:

---

Originally Posted by david beenstock

Hi everyone, Thanks for all your advice.
As I had almost exhausted all other faults (cables, drivers, MPU, APU etc.) I replaced the motor, even though there were many who said that stepper motors are unlikely to fail. Found a very helpful company who managed to match the Xenetech motor, even though there was only a generic label on it.

This is where your further help is needed.
The Z-axis works perfectly!
But the X-axis is now straining and not starting at the correct place! So I need to engrave a dot to locate it's starting point!
However once I have determined where it is to start it engraves perfectly in all axis, also if I press mechanical home/home cancel it goes home correctly, if I press home retain it again engraves perfectly over the previous engraving.

Any advice whats happening now?? I doubt it is the X stepper?

One other answer might solve the mystery, I got detailed info on the wiring of the motor as there were 8 wires and I needed only 4, which wires should be combined and which wires were A-/A+/B-/B+, I just wired them in this order into the junction box and it worked!. There are 24 combinations of matching 4 wires to 4 connectors!!! Is it possible that they can be wired differently, work perfectly but not cause a conflict on the X?

You've got your homework!

David

---

Should not cause a conflict.

Run your job with the spindle up & off and that should take it out of the equation. If need be you can disconnect the wires to be 100% sure.

Things to check:
On the table there is a circuit board the cable plugs into. pull the cover and see if the board & wiring are OK. (not burnt)
Check leadscrews for cleanliness and lubrication.
Check linear bearings for cleanliness and lubrication. Be careful not to let them come off of the rail.
Check spindle motor brushes (if it has them).