Alignment between machines - CNC router and Glowforge


#1

Hi,
While anxiously awaiting my Glowforge, I am thinking about some projects that would involve my CNC router as well. For example, for thicker material, cut out a shape with the router and then engrave a design on the surface with the Glowforge.

In my experience with my router, I’ve found that it is more reliable to base my designs around the machine’s (0,0) XY home point since that is something I can find with good repeatability. I’ve also developed some jig and fixturing techniques to be able to replicate a design or reliably work on both sides of a piece of material.

Does anyone have any tips on how to arrange the workflow between the router and the Glowforge to make this process as seamless as possible? For example, which process should go first? I’m thinking it might be best to do the following.

  1. engrave the Glowforge design on the material
  2. simultaneously have the Glowforge cut (as deep as possible, if not all the way through the workpiece) some location holes on the material that are outside of the finished boundaries of the project
  3. If the Glowforge can’t go all the way through, say for example on a 2" thick piece of hardwood, use these location holes as drill guides to drill all the way through the material - might need drill press to make sure holes are perpendicular to the workpiece
  4. use the CNC router to drill holes at corresponding locations on the wasteboard
  5. use same diameter plastic pins to line up the Glowforge-located holes on the workpiece with the CNC-routered holes on the wasteboard.
  6. run the program on the router to finish off the project

Curious to see if others have tried a similar approach or if there are any suggestions on achieving this desired result. Also curious to figure out how to do a precise alignment when the workflow is in the opposite direction - i.e. routered first and then lasered second. Or maybe there are multiple steps back and forth depending on the project. Ideally, the camera on the Glowforge would help with the alignment process, but from what I’ve read, the alignment process is not all the way worked out and might not get down to the same level of precision as I’m thinking of here.

Thanks!


#2

I have not yet had a chance to test out a workflow, but I’ve been thinking about this as well. One of the reasons is that I want to be able to use the CNC to get true flat edges, instead of the slightly curved edges of a cut made by laser.

For engraved designs, I’m thinking that I would use the laser to cut out a slightly oversized piece and then be able to index off of a corner on the CNC to trim down to size, and do anything else on the CNC that I need to do. If necessary, I would use the laser to engrave cut lines into the piece (outside of the final area that I expect to keep) and cut down to calculated size using the table saw, band saw or miter saw before putting it on the CNC.

For complex designs that won’t allow me to index off of a corner, I’ve thought of using some index hole(s) or other position that can be easily calculated from the design.

If going in the opposite direction, you’ll have to cut a jig on the laser that you can put your CNC’d piece against to make sure you are square with the laser head. Without precise positioning on the GF, I don’t see any other way to do it.


#3

Regarding squaring to the gantry, I use a few end scraps of hardwood, 1x2 &1x4. Either square off of the front door (mostly) or the crumb tray raised edge, left or right.
Drop the block against the door or edge, place the work against it and remove the block. Most woods exhibit a degree of warp, so I use magnets to hold down.

Once you have your laser, you will quickly develop your own favorite workflow between the machines. :sunglasses:


#4

That’s the way I’d go at it. Use the same design file for the laser & the CNC. After cutting on the CNC, use the GF to cut the outline out on some scrap to make a jig. Drop the CNC cut part into the jig, turn off the cut line and enable the engrave line. No tricky lining up and indexing needed.


#5

I was actually just about to ask this question. Thanks!