Category Archives: Laser Cutting

The Value of Prototyping

Power vs Speed grid to determine proper levels for the desired depth & darkness in black walnut wood.

One of our members wanted to make a commemorative plaque for his church using the CNC and laser engraver at Castlemakers. I volunteered to help, thought it would be a good chance to use our bigger CNC with some newly updated software and we could both learn in the process.

CNC plaque cutout with the first prototyped laser engraving.
First engraved prototype in plywood next to a full thickness pine cut out on our CNC.

Given the nice wood they wanted to use, doing several prototypes with lower cost wood seemed in order. It also would give him something to show the church committee approving the plaque. Ed was able to locally source some rough cut black walnut wood and another member Ian used his planer so the wood could be glued to an appropriate width.

In the meantime one of the other church members created a great looking design for the engraving. For the first prototype, done in birch plywood, we just used the laser to cutting the shape to show others for approval. This resulted in a few minor changes and a decision by the group to add gilding to part of the dove and the rays on the plaque.

Black walnut test gilding before changes.

The final plaque is on darker wood, so we engraved a sample portion on some scrap black walnut and it’s a good thing we did! The original rays were too thin, making gilding extremely difficult. Now with the final design was completed, another prototype was made in pine the thickness of the final plaque to make sure the CNC portion of the project was going to work with the engraving.

Laser Etching Glass

Glass fusing and slumping equipment
Newly donated glass fusing and slumping equipment.

It started right after some donated glass fusing and slumping equipment, more on that in a future post, that was dropped off at Castlemakers. Troy, one of our more creative members, came in during open shop night with a sheet of glass and asked what our laser engraver/cutter would do to it. Since I wasn’t sure, it seemed like the perfect opportunity to find out.

Etching glass with our CO2 laser.

As it turns out it, it works great for etching! Power settings were modest and it gives a nice frosted look to the glass in a single pass.

Cutting really didn’t work though. We weren’t totally surprised that cutting would be more difficult, so started experimenting with the settings.

With wood or acrylic you can make multiple passes that will continue to cut through the material. A slower process, and sometimes takes refocusing the beam, but you can get the job done.

CO2 Laser Cutting Glass Results

In this case we learned that the glass seems to absorb enough heat that it starts chipping and cracking. Perhaps it was the type of glass we were using, the glass used was a home project leftover. You can see from the picture it was not a clean cut and eventually created a longer crack in the glass. For now we’ll just manually cut glass until we get the new diamond saw setup. But we did learn how to etch using the laser!