Laser + Vinyl Cutting

This week had three parts:

  1. A group session to characterize the laser cutter for its kerf and validating different slot designs such as with a chamfer.
  2. A small vinyl cutting assignment (which was much more fun than anticipated).
  3. The press-kit laser cutting assignment.

Make me a sticker

I didn't know what vinyl cutting was and I have to admit that this machine is fun to use. It does work slowlier than a laser cutter and we only used it on vinyl, so I don't know whether it will be used for anything else, but making stickers feels great.

One of my favorite animals is the seal, and of course, this was asking for a "seal of approval". I found a nicey seal logo, which I thresholded on Gimp, and then vectorized on Inkscape using the "Trace Bitmap" tool to then go back to gimp with a much smoother-looking larger-resolution black and white image. Note that I modified the black/white mask to add a smile on the seal since it was missing one.

Finally, I used the Mods software from Neil with a 150 DPI resolution and eventually there it is on my laptop!

Group Characterization

See our group page for the results: the Purple Anteaters.

Press Kit

My first intention was to try to generate a press kit for my ornithopter by slicing it and generating slots automatically using feature script, notably the Laser Joint feature. Unfortunately, the joints that it generates are used in different scenario that ours.

I then decided to try OpenSCAD which Ben had been using notably during the group project, and quickly realized that there was a steep learning curve, especially because there was no actual user interface. There was only coding, which means a necessity to know all the functions. I fortunately found the cheatsheet so I could generate my first meaningful result. I wanted to generate the ribs of my bird with openscad, but eventually decided to go back to OnShape because I realized that that was very easy if only working with sketches.

Back in OnShape, I generated multiple parts that would be a sufficient grammar for building my bird. I made use of new replication tools that were very useful for multiple slots including

I created a few rectangles, squares, variants of ribs (looking like C's) and the critical "triangle" which is needed to get non-square-like results, especially important for the tail.

I laser-cut these with a few attempts because the export from OnShape to DWG and then from Illustrator to SVG (I wanted SVG, which was not actually necessary for CorelDraw!) was not only complicated, it messed up the scaling at some point. I still don't know where that happened. But the result was that I tried a few times, and the Cs were too short. I then made it successful for the rest, and tried on a different laser cutter (smaller bed) with the Cs while I was waiting (long queue), and the corrected scaling was wrong again there. I must have done something wrong with the export of the Cs or there is a special parameter that scales them when importing in CorelDraw. I could not tell.

Finally, I started to assemble these into what eventually looked more like a dragon.

And I tried to mix the actual process with very cheaply made on-the-fly wings that would give it a little bit more of a face. I basically manually cut extra pieces that looked like flapping wings, with a small slot.

And finally we have a more consequent dragon. Note that there are square supports for the wings (arms?) as well as multiple feet to support the long body.

Going farther

I would like to get a correct feature script that automates the decomposition into parts for laser cutting. Doing small pieces was fun, but it was not derived from a real result that was slowly cooked on OnShaped, so I am still missing the possibilities that OnShape provides here. The fact that it is possible to add pieces a posteriori is a great advantages. I could especially add pieces that are not in cardboard and mix materials!