Laser at work just started doing this. Anyone seen it? Problem

[Clark Pace]

Hello,

My laser at work started doing this. See pictures. On anything I cut, circle sqaure etch.. I get uneven line. When I go really slow it looks like hand saw metal edge would look like. (teeth)

CAM00050.jpg

[Scott Shepherd]

What kind of laser?

[Clark Pace]

Sorry. Hamna Laser. It's a chinese brand. I know, but people have not heard of it.

[Matt McCoy]

I would check:

1) Clean the rails -- top and underside

2) Gantry is not loose

3) Belts are adjusted properly

4) Wheels are adjusted properly and not unevenly worn

[Michael Hunter]

Adding to Matt's -

5 Check that mirror/lens assembly on the X carriage is not loose.

6 If the bearings of the carriage are adjustable, make sure those are good too.

[Kev Williams]

My bet is crap on the rails and/or the rollers, or the belts and/or belt cogs.

If you have time for a test: First thing to check is to see if your lines per inch (or 'gap' or 'interval' or whatever your software calls it ) can be set to run at around 50 lines per inch. In mm .5 would work. This will space your raster lines at about .02" apart.

Tape a bunch of sheets of paper to each other to cover the entire table, and tape it to the table...

Then, using a 1" margin all around, fill the rest of the table with black box to engrave...

Figure out a speed and low power setting and then run it. Since you're getting 'teeth' at a slow speed, I probably would start out fairly slow.

Now, find where the bad spots are.

If they repeat across the table at fairly equal distances, then figure out how far one rotation of the stepper gear moves the laser head, and see if the spacing correlates. If so, you may have some bad gear teeth...
If the distances don't correlate with the stepper gears, then check how far the rail guide wheels move the head in one rotation. If the spacing fits, check the wheels close.

If you find a pattern repeats running in the Y axis, then check the Y-axis items--

If the bad spot(s) mostly happen once across, could be the belt has some bad teeth.

If there's no repeating pattern, you may have some bad bearings in the gears or guide wheels that are causing random bad spots, or as other have suggested, mirrors or lens may be loose. I've run into a loose lens a couple of times with my Triumph, the screw-in collar came loose (since I've busted a few lenses I'm wary of going too tight!), and a couple of weeks ago my LS900's lens cup just fell out while engraving! All the engraving it did just prior had to be replaced too (fortunately it was my Rowmark I messed up) Speaking of my LS900, not long after I got it, I started getting shaky engraving, kind of random in the raster direction, and mostly on small items like 3" badges and such. But I found the pattern repeated at equal distances DOWN the table. Turned out a hot spark from something embedded itself onto the teeth-side of the small Y-axis drive belt, and deformed it. Every time that part of the belt hit gears the engraving would get all wacky....