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Unread 21-07-2008, 12:20
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Re: Acrylic Gearbox Sideplates

Quote:
Originally Posted by AndyB View Post
It has nothing to do with cost for us. It completely comes down to machinability. You can't cut polycarb with a laser... or at least not the same laser.

We do have CNC mills at our university but it is much more of a hassle to access them ordinarily. And we don't have any engineers on our team that have experience in using them.

But thank you for the advice.

What kind of laser is it?

Our laser cutter will cut both polycarbonate and acrylic, among other things, but there are some caveats. The machine can't cleanly cut through anything thicker than about 1/8" polycarbonate before the material begins to melt around the cut. Thinner material cuts quickly but chars. Acrylic, on the other hand, cuts like butter up to 1/2" thicknesses.

If the laser can cut acrylic, there's a pretty good chance it'll be able to cut ABS with little trouble and Delrin with a bit of coercing. Similarly to polycarbonate, Delrin can begin to melt around the cut. We can get through 1/4" Delrin in a single pass, but for anything thicker, we'll usually run multiple low power passes instead of a single, powerful cut.

I would not feel comfortable with acrylic in a gearbox. They see more loading than you realize, I think. CIM motor windings are pretty chunky and rapidly changing their direction throws quite a bit of their weight around, so to speak.
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