So I finally have my x1390. Laser Engraving Machine - Low cost Laser Engraving Equipment System by Redsail

A few questions.

1. I'm using it to cut shapes out of acrylic, 1/8" x 32"x48" sheets. I'm just curious as to general power and speed settings to cut this acrylic. I've obviously played around with it and cuts decent, but I'm not sure what I should be looking for. Right now it seems like I need 80% power at a fairly slow speed to cut well.

2. What is the recommended distance from the material should the laser sit. Right now its 15mm as recommended by the manufacturer, but seems high to me?

3. This machine does not have a Z-Axis; trade off for getting a large machine for a good price. I need to shim the acrylic sheet up about 1" Just been messing around and have used wood temporarily. Would it be worth while to cover the wood with a thin sheet of aluminum or something so the wood isn't consistently burning