Laser cutting 10mm sign lettering

[Keith Colson]

I made a good discovery today. When I cut out 10mm Acrylic sign letters they are always hard to remove from the sheet and sharp corners quite often come out with little chips on the corners due the acrylic re-amalgamating. Here is the process I am doing now.

I run the acrylic with two passes at double the speed with an auto z height change. With this process the letters come out easily and the corner chips are totally gone. The machine time is pretty much the same.

Here is my process
1) Put the artwork on my green and red vector layers
2) Green cuts first for me so auto Z the green to 8mm (2mm focus under the surface)
3) Set the red layer for an auto Z height of 5mm

Normally I run one pass with 80% power and 1.3% speed @ 500ppi. With this process I run 80% power and 2.6% speed @ 500ppi. When you have a 1.5 hour job of letters in the bed this saves me a lot of cleanup and removal time. ( I only run 80% max power in summer here as I don't like my laser getting too hot)

Cheers
Keith

[Clark Pace]

What lens do you have? My 60wat ULS could cut through that thickness without any chips? My current china laser can also cut through 10mm in 1 pass, and it's 60 watts as well. I would do some further testing.

[Mike Null]

My 45 watt can cut through in one pass but I always use two for a cleaner cut. I agree with Keith's method.