adding 75 watt cartridge

[Mike Lassiter]

We are getting a second laser cartridge today to go with the 60 watts we currently have. Any ideas of what thickness material we will be able to cut with both?

[Paul Phillips]

Mike, congratulations, that's enough power to have some real fun with. I have 120 watts on my machine, I haven't done a lot of testing but I have been able to cut through 3/4" Maple, Birch and Alder, MDF and Plywood don't seem to do to well with that much heat though, I can get through it but not cleanly, maybe with more testing and passes it can be done. I can just get through 3/4" Acrylic with my 2.5" lens in one pass with ok results but I still see some striations towards the bottom of the cut, 1/2" Acrylic seems to be the sweet spot for me, it cuts like butter with near perfect edge quality. I can also cut 1/2" Corian in one pass but the edge quality will never be as clean as Acrylic because of the mineral content and the edge quality can actually vary quite a bit from one color to another. I like being able to do deep engraving in Acrylic and Corian in one or two passes. Apart from that I think you will simply see an increase in speed and productivity over what you have been doing, all your speed settings should increase a significant amount. I can't imagine not having less power to what I do every day, I know you will be happy with your decision.
Best of luck and let us see some of your work after you get it!
Paul

[Rodne Gold]

Adding more power has as it's major advantage of increasing cut speed rather than being able to cut thicker stuff,
Thickness is governed a lot by lens focal length , to take advantage of the extra power for thicker cutting you need a longer lens - the extra power will increase the power density of the bigger spot of the longer lens. With less power the bigger spot of the longer lens would not have enough power spread over it to really start the vaporisation process whereas your extra 75W will enable it to vaporise quick , leading to a better cut.

[Mike Lassiter]

We have 3 lens - The HPDO (?) - the real expensive one, 2" & 3". We had to go with the 3" lens cutting fabric for Christmas Stockings due to the bottom of the traveling exhaust housing dragging the material and moving it while cutting with the 2" lens

[Rodne Gold]

Your 3" will work , tho for really thick stuff a 4" would be worth trying , will probably maximise your extra power (at the expense of a thicker kerf) Acrylic doesn't really behave like other stuff in regard to lens focal length , it acts like a waveguide , even a 2" lens will cut 1" thick acrylic
Just as an aside I have never really been in favour of a laser processing wood , a CnC overhead router works much better IMHO..

[Mike Lassiter]

3" is longest focal length ULS offers for our laser.

[Scott Shepherd]

How are you processing acrylic with long focal length lens? Every time I've ever tried, it's been a disaster. The air assist ends up being so far from the cut, it gets nothing but flare ups and there's no ejection of material through the cut.

[Mike Lassiter]

Scott I haven't used the 3" lens for acrylic. We had to go with it to get the traveling exhaust housing high enough to stop dragging the fur material we make Christmas Stockings out of. The" lens allowed the fur to be moved as the carriage was cutting because the traveling exhaust housing goes down low enough below the carriage it was basically sitting on top of the fur. 3" lens works great with 60 watts cutting fur material. I could cut 4 side pieces that will make 2 stockings in right at 2 minutes. Haven't cut any in a while as we cut most of the material when we got it so they would be cut and ready to sew together as needed. It takes longer to get the fabric pieces off the table and pull the roll back across the table for the next run than it does to cut it.

[Dan Hintz]

How are you processing acrylic with long focal length lens? Every time I've ever tried, it's been a disaster. The air assist ends up being so far from the cut, it gets nothing but flare ups and there's no ejection of material through the cut.

I would imagine a custom cone would be in order here... bring the air closer to the material.