"Double line" effect on Y axis lines when laser engraving

[Matt Williams 407]

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Hello everyone, I'm hoping somebody can help with a frustrating issue. I'm getting an unusual double line effect with the laser but only on thin straight objects where the line runs on the Y axis. On the + sign the lines are identical in the file, and if it is rotated 90 degrees it will still only be the segment that is aligned with the Y axis where I get this effect. These examples were cut with the work piece mounted on a rotor, but it still occurs when using the laser normally. On most materials the effect isn't very visible, but with Cermark it is glaringly obvious. The machine is a Boss Laser with a 100 watt glass tube, used with Laser Works V8 software.

Any insight? Thanks.

[Kev Williams]

Interesting how the sides of 'pure' vertical lines are crisp and clean, and every other line is a fluffy mess...

All I can think of to check for starters, is -- how tight is your X belt and the X axis rail/carrier bearings? It almost looks like severe vibration is going in the X axis. Too tight a belt might cause this if the belt teeth aren't aligning to the cog correctly due to high tension. Or, maybe too loose, if the belt starts 'strumming', it might cause enough vibration to wobble the lens head.

A split beam could cause this effect I suppose, but I'd think the vertical sides would also be affected. But check your lens and mirrors for cracks--

Same thing with a loose lens, if it was loose I'd think all the engraving would suffer.

Pretty sure it's something mechanical and not electrical...

[Scott Marquez]

What Kev said.
Loose mirror, or loose mirror holder.
Crack in your focus lense.
Alignment issue and you are hitting the edge of your nozzle after the focus lense.
Scott