Laser Cutting (very thin) Polycarbonate

Laser
#1

I need to cut precise holes in a Lexan film of 10mils (0.25mm) thickness. Looking at some previous discussions, it seems that there is a “Just Say No” attitude toward Lexan, however the Materials wiki Material #2 line specifically states “>1mm”.

Is this an acceptable use of the laser?

Also, I’m trying to get the exact MSDS for this film to see if chlorine gas is truly emitted or not. It seems like there is conflicting information on the wiki / online. Specifically the wiki does not give this a (T) rating, however there is a dire-sounding warning in the header paragraph of the materials wiki:

“For example, Polycarbonate/Lexan produces flames and lethal chlorine gas which will rapidly corrode the machine into uselessness, and is extremely hazardous to the health of people nearby.”

Regardless of the answer to my specific question, the wiki should be made consistent, one way or the other.

Thanks!

(Slightly edited for clarity and removed reference to old thread since the discussion was moved to a new thread)

DISCUSS Laser NO GO Material #2: > 1mm Polycarbonate/Lexan
#2

I’m gonna go out on a limb and still say it’s a no go. It’s bad for the machines.

Thickness doesn’t matter. Please don’t cut it.

@michaelb can clarify further

1 Like
#3

I’ve updated the wiki page.

I would love to allow thin polycarbonate, but for now I think it’s best that we just avoid it. In my experience PC can produce a lot of smoke, and while not toxic it can quickly foul optics, so until we have an exhaust system that can properly clear smoke from the cutter (soon, hopefully?) let’s not go there.

2 Likes
#4

OK. Thanks for the quick responses!

#5

We will, post expansion, have a plastics committee with their own tools and workshop, but in the meanwhile you might consider reaching out to the machine shop. They can get hella precise.

#6

Thanks for the tip! I’ve just posted in the Machine Shop topic.

#7

Not sure what year that will actually happen but when/if we do we’ll have a cnc router set up which could do this. For precision, you can start with a small end mill and extrapolate the hole to an exact hole size to within a few ten thousandths. The HAAS can do it, but it requires more training and a knowledge of machining.

2 Likes
#8

How big are the pieces? Could this be done on the shapeoko?

#9

He said he needed it to be precise :rofl:
Seriously, my only issue with the Shapeoko is how the origin is found. You just kinda eyeball the location. Sure the movements will be precise but from what origin? How are edges accurately found? If some type of edge finder can be used then sure I agree. But if you need it to be .813" from the edge, using the swag method ain’t gonna cut it. Sorry, not being a downer, just a machinist who live by accuracy for a living.
IF he really doesn’t need it to be THAT accurate, then I second the use of the Shapeko.

2 Likes
#10

Isn’t this no different than on the Thunders?

#11

yes. exactly.
if the thunders accuracy were good enough, then the Shapeko will work for you.