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View Full Version : Out of focus for 'softer' cut?



Mike vonBuelow
10-22-2010, 10:00 PM
I'm assuming you'd raise the laser head to do this??

If so by how much?

John Noell
10-22-2010, 11:51 PM
Either up or down will move you away from the focal point. I dunno about "softer cut" but I do 2nd passes (and change DPU) to smooth out rasters on acrylics. (I make molds for a chocolate company, so they can make customized chocolates with logos for resorts.)

Richard Rumancik
10-22-2010, 11:54 PM
You can go out of focus either direction. For cutting I would usually focus into the material. For raster I think you could go either way and achieve similar results. The amount will depend on the focal length of the lens - a long FL lens will require more z-travel to go out of focus. For a 2" FL lens you might go 1/16" to 1/8" OOF but it really requires trial-and-error to achieve the effect you want, as it is also very material dependent.

Dan Hintz
10-23-2010, 10:10 AM
Raising is better than lowering as it moves the lesn away from a potentially nasty material...

John Noell
10-23-2010, 2:21 PM
Raising is better than lowering as it moves the lesn away from a potentially nasty material...On my laser it is the bed that moves up and down. "Down" is further away from the lens for me. :)

Pete Bejmuk
10-23-2010, 2:36 PM
with shallow rastering on cast acrylic, i find that focusing into the material .1" helps get rid of the banding that may appear, giving it a softer etch.

Dan Hintz
10-23-2010, 8:37 PM
John,

The OP mentioned raising the laser head... hence my suggestion that raising is better than lowering.

Mike vonBuelow
10-23-2010, 8:57 PM
I guess I should have asked 'extend' or 'contract' the distance...

the raising or lowering is the means to the end

Robert Walters
10-24-2010, 1:18 AM
I make molds for a chocolate company

Is that via vacuum forming or strictly the laser, and how thick if you don't mind me asking?