A stately origamic architecture / kirigami pop up manor for snow elves, sent for the 2021 winter holidays.Continue reading
This scrap (faux) leather bag with a Celtic key theme is an initial exploration of a technique for using small scraps of leather or similar material leftover from other projects. I thought the tiles would be fun with a minimal Celtic key pattern motif in the center of each, then leaned into the theme with a circular key pattern ring on the bottom and, some 3D printed key, sculpted in Nomad Sculpt.
The SVG for the “leather locker” tile is linked below. You will likely want to adjust the slot height to match the thick ness of the material you are using. Let me know if you use it to make anything interesting!
This is an update to my last post on modeling Celtic knots in Nomad Sculpt and creating depthmaps in Blender to carve with laser engravers and CNC machines. A newer feature in Nomad Sculpt makes it possible to export a depthmap directly, without having to go through Blender. A checkbox option in the debug menu (named “Heightmap”) switches to a depthmap view, which can be exported as a render. For best results, use a bitmap editor to spread the dynamic range.
I made a short video with a walkthrough:
I came up with a fairly simple workflow for creating 3D models of Celtic knots, used those to create depth maps and, used the depth maps to do 3D carvings on a laser (Glowforge) and a desktop CNC machine (Nomad 883).Continue reading
Dice reliquaries from laser-cut hardwood ply.Continue reading
I made another dice bag with a new embossed velvet design. Some incremental improvements to the process for making the embossing plate: I switched to using 3M 468MP Adhesive Transfer Tape for the glue-up. It seems every bit as solid as the wood glue and, was a lot less hassle. More of the details are covered in the short update video below.
The kumihimo drawstring for this bag was done with glow floss for one of the colors and purple for the other. The glow from the floss is noticeable in the dark but, not especially bright.
By comparison, the 3D resin printed glow-in-the-dark skull beads are quite bright, especially after charging up with a UV lamp for 30 seconds or so. I used the Siraya Tech Craft resin for those.
[Amazon Associates links benefit a local arts organization.]
I played with several variations of this snowflake design back around 2002. There were a couple 180-degree-open card variants that I liked. They were both designed to be cut as four panels that folded together to produce a card with an integrated backing. I had some limited access to a laser cutter for a couple hours to produce the cards. I ended up going with the simpler of the two designs for the production run. That one was less sensitive to smoke deposition and, less fragile.
I always wanted to play with the other design a little more and, in 2020, I finally did a run of those on my own laser.
Smoke deposition was still a challenge, especially on a stock with a pearlescent finish and a little tooth. There is almost always some trade-off with that sort of thing and expedient production. I chose not to apply all of the full repertoire of techniques for these, opting to reduce wear and tear on expensive work-holding mats and, to make production faster.
I made a short production video featuring the jig-in-place technique, dry transfer adhesive and removing stray glue.
I played with some green screen chromakey stuff for video last year. It’s a bit fiddly to get the screen and the subject lit right for it to work well.
I was excited to learn that it was possible to get better results with a retroreflective screen and a colored light ring. The general idea is that the fabric reflects the light back in the same direction from which it came. By shining even a relatively dim colored light at the screen from right around the camera lens, you get an almost perfectly-even colored background. It is much less sensitive to the subject’s distance from the screen, etc.
John Park posted a project write-up with his plan for building an appropriate light ring a few months ago. It looked pretty straight-forward. So, I gave it a go. My 3D printer is not large enough to print his mount design in one piece and, I didn’t really want to mess with printing in sections for assembly. Instead, I did a quick (and pretty sloppy) adaptation of the design in lasercut acrylic. The LED ring sits in a channel made with a bunch of little L brackets, glued on with acrylic solvent. Similarly, the grippers are several layers of acrylic glued together.
The electronics design and code are all straight from John Park’s project.
This works really well! Light spill on the background from lighting the subject can still be a problem. I was able to adjust settings for the chroma and luma range in post to compensate where I had issues pretty easily, though. In later attempts, I was more careful about where I pointed my lights.
It is not clear from the photos but, it is better to get the screen as flat as possible. It works with a little wrinkling but, it makes the light spill issue more likely. I tightened the screen to the frame a bit more for later attempts.
It is also worth noting that the retroreflective fabric bruises pretty easily after its protective film comes off.