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View Full Version : Dark cloud: my LS900 is fritzing out...



Kev Williams
10-11-2017, 1:16 AM
--But there is a silver lining...

Yesterday I noticed the X stepper motor 'thumping'... Uh oh...

Occasionally when the rotary's plugged in it'll thump. I can make it quit by wiggling the rotary's plug. But it's never thumped otherwise till yesterday.

It's been idle all day till about an hour ago when I started a stainless job. While setting up the next job all of a sudden the laser starts making racket and the laser head is thrashing back & forth, so a hit the pause button as fast as I could. When i hit the reset, the head was 'stuck' briefly until the Y got home, then the X went home. I rebooted, and tried to pick up the job where it left off. About 3 sweeps in the racket started again-- best way I can describe it, is if you took a Dremel tool running full blast and then pressed the whole thing against the laser box... or an extremely amplified dentist's drill.

And a bunch of dollar signs with wings started to fly away... I just paid off the IS7000 last week, so it just figures ;) ...

But- after a little trial and error testing, I discovered the machine is acting EXACTLY like the Triumph did when it was messing up-- as in, only the X is messing up, and it only messes up at certain Y coordinates. Both machines, not ironcially, messed up at around the half-way point. And the problem with the Triumph was:
This broken wire ------- within the drag chain...
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--the repetitive bending within the chain does take it's toll.

And the silver lining? I KNOW this is the problem with the LS900, because I was lucky enough to actually see a wire spark in the chain when slewing the head up and down. So all I need to do is spend a couple of hours repairing some wires and connections, and I can put those flying $$$ back in their cage... :D

Kev Williams
10-11-2017, 2:38 AM
fixed!

This machine looks like a nightmare to work on but it was actually easier than the Triumph. To remove the side, there's one screw on the top, in back, it has to come out. In the box there's 2 screws to just loosen, and the whole side pulls out. The chain & wires are right there.

No sense of humor with this chain, but when I finally got the links out of the way, this is what I found-

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I snipped it in half, trimmed the ends... Now they're too short, so found some wire in the back room, opened up a 1/2" length and tinned it, then soldered it between the green wires...
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I covered the repair with the heat shrink plus some black tape for good measure.
To get the chain apart I had to snip sections out of it! Like I said, no sense of humor... At least the Chinese put removable cross bars in their chains! ;)
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To cover the open spots I just put electric tape over the bars. How long it'll stay, who knows. I also put down a piece of tape under the chain.
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And the machine runs like it did--day before yesterday! :D

I'm happy, once again I avoided spending any money to fix a dead machine! ;)

alan corder
10-11-2017, 6:58 AM
Don't you just love a happy ending. Well done!

Bill George
10-11-2017, 7:53 AM
Nice job, but.... you need to plan on replacing that entire bundle of wires sometime. You could pre-make a splice in bundle color for color and then do the splicing out of the flexing area. Since all those wires have been flexing for years, its just a matter of time before they all break.

Michael Henriksen
10-11-2017, 7:54 AM
The Chinese machines are easy to work on and the individual parts don't cost a fortune. I had a wire break in the LS3040 I had many years ago - easy to spot and easy to fix.