3D Printing on Fabric – Dragon Scales

In our upcoming production of Macbeth at work, one of the many spooky ingredients that the Three Witches drop into their wondrous cauldron is "scale of dragon." To that end, I'm helping our props department out by printing some dragon scales onto some toule. The design is essentially some raised, horned scales repeated in a hexagonal pattern.

The print is in silver eSUN PLA+, which strikes a nice balance between the darker, dull tone of most grey filaments, and the super shiny "metallic" filaments. eSUN PLA+ has become my defacto standard in the past couple months, after I used 4kg or so to complete a project printing portable 

So far, I've had three failed prints with this file and technique. The first was my own fault: after pausing the print between the second and third layers to insert to toule, I hit "Stop Print" instead of "Resume Print." Arg. The second and third failures, though, are a mystery. They appear to have stopped extruding following printing the bottom layers before starting on the infill and walls. I don't know why exactly this happened, as I started both prints late at night after work before heading to bed. But both times, I came out in the morning to find the print head at the final Z height I would have expected had the print completed... but with only a small bottom layer of rectangles trapping the fabric.

I'm currently printing the pattern again, re-sliced. Here's hoping!

Update after printing: close, but no cigar.

Re-slicing the file alleviated the "no extrusion after the bottom layers" problem, so I can only assume it was some odd setting in Cura that was to blame. I'd been trying out a "pause at given height" plug-in script, but a little more googling has lead to believe that this not usable in its current form with the Duplicator i3. Perhaps that was the cause.

This time, the error was my fault. It seems that one of the binder clips holding the toule to the heated bed was contacting the frame of the printer at one end of its Y travel. This only turned out to be an issue for the top %30 of the print, when the tip of the "frontmost" scale leaned far enough in the Y+ direction to cause the binder clip to contact the frame. Thus, everything above this level shows layer-shifts every two or three layers as the clip hits the frame and causes the y-stepper to skip a step.

Back again later with smaller binder clips!

Designing 3-Way Initial Blocks [Video]

In my experiments  with Fusion360 recently and casting around for inspiration, I stumbled across my old copy of Godel, Escher, Bach: An Eternal Golden Braid, which has a curious cover design consisting of two objects that cast shadows of three different letters along three different axes. In the following video, I look at the process of designing one of these shapes with arbitrary letters for 3D printing.

 

Faceted Lampshade from Clear PLA

I’ve had a clear, “low poly” angular sculpture in clear PLA sitting on my self for awhile now. Earlier this week, I turned it into a lamp shade.

I built the original model in Blender along the lines of this video from Maker’s Muse. The gist of the process is:

  • Start with a basic solid, like a sphere or a cube.
  • Decimate the solid (reduce the number of triangles that make up the shape) to a very very low level, perhaps down to 20 or 30 polygons.
  • Stretch and place the vertices of this blocky solid until satisfied.

In this case, I had ideas about turning this shape into a lighting table topper, with an Arduino and LEDs underneath the open base. But other projects popped up, and this open-base blocky pyramid has sat dormant for several months. This week, I finally found a use.

In my living room, I have a tall two-socket light fixture standing in the corner. One socket stands at the top of the lamp, with a broad frosted dish shade, and there’s a small flexible arm coming off the side of the lamp which lost its shade long ago. My partner and I both enjoy using this flexible arm as a re-positionable reading lamp, but that lack of a shade means it’s been pretty glare-y.

By trimming the top off of the clear pyramid, I converted the Agrocrag into a lampshade.

The shade is trapped in place by the bulb itself. Of course, an LED bulb is a must, since the heat of an incandescent (or even CFL) light bulb will melt or deform the shade.

Just a little project-reuse for the home!

Hello, World! Again!

I must have started half a dozen blogs in my life. I still maintain a separate one for Ham Radio at KK9JEF.wordpress.com. I’ll have to see about transferring those posts to this site.

So why another new blog? Two reasons:

  • My blog at KK9JEF.wordpress.com was specifically for my Ham Radio projects and learnings. As my hobbies expand into other areas, I thought it might finally be time to have a general-purpose personal hobbyist blog.
  • I’ve always struggled to find the balance between blog posts that catalog a completed project in whole. For example, my entire K3NG Morse-Code Keyer Project was wrapped into one big post, but I split up my Beach 40 Build into multiple small sections. Neither is perfect – the “blog as you build” method leaves a somewhat scattered trail for those who come after and want to replicate what you did (which is sometimes you in the future), but the “wait until it’s done” method means a lot of the process is undocumented.

To that end, this new site has both BLOG and PROJECTS sections – the blog can be for more single-shot observations, and the projects subpages can contain coherent descriptions of where a particular build or project is at.

It’s worth a shot!