Use material thick enough for both slots. Cut the wide slots first from the bottom side then cut the narrow slots last with the same bit. No need to change anything or rezero/home. Drawing it in CAD to do this in VCarve or Cut2D with one gcode file should be an easy task. When done, just glue a thinner backing material to the bottom. If you can, recess the backer piece into the main piece, and no glue seam will show from the side.
Edit: Just realized Daryl posted a similar suggestion.
The link I posted, from the ShapeOko wiki shows the G-Code that is and is not supported by grbl.
If you think ahead, you can do it in two layers, but in a single cutting session.
Take two squares of material, and hot glue them together. Lay out the maze pattern for the narrow and wide paths in whatever program so that the narrow channel is inside, and below the wider one. Set your cut depth as close to one layer’s worth of material as you can (trying to just graze the surface of the bottom layer).
Have it cut the maze and cut the round outline of both layers. Split the layers apart, and flip over the top layer. Sand the bottom layer until the ‘tracings’ the XCarve will have left in it are gone.
Glue the two back together, this time permanently.
At least, that seem to me like it ought to work.
No bit changes, no alignment problems.
Hi Brian, did you test and succeed to cut the mazes in 3/4" MDF using a T-slot router bit with the X-Carve ? I’m actually interested in a quite similar project, so a response from a practical use would be of great help.
I did. I used VCarve Pro to output the program. I had to manually cut out the last portion of the program, but as long as you can edit Gcode, no problem. Vcarve had the cutter plunge and retract in the same spot, so it didn’t ruin anything, but I did not figure out how to set the start and stop point, it just happened to fall somewhere it was acceptable.
There is a tutorial on selecting your start poing. Assuming you found it by know. Use the node editing tool, select a node and right click it. Select, “Make Start Point”
I use a keyhole slot cutter with V-Carve to make keyhole slots, but I edit the g-code to nibble, and retract, nibble and retract as it moves forward. It was a pain to get it right, but once it’s done you never have to do it again.