Good morning from my Robotics Lab! This is Shadow_8472 with a side project of the week. Let’s get started!
The Game Quilt
My mother is made a quilt for a kid who will be spending his summer in the hospital this year recovering from a painful procedure. An accompanying game board has Chess/Checkers quilted onto one side and Tic-Tac-Toe on the other. The idea of paper Chess pieces glued inside some bottle caps grossed me out. I demanded to make something a bit nicer. I browsed the available Chess sets on Thingiverse and settled on a short “travel” set [1].
The Black Army
My printer started the week loaded with black filament, so I printed the black army first. I scaled the pieces up to 150% to match the board and made the bases solid to lower pieces’ center of mass. I tested these changes with a queen and the result needed a larger crown topper that wasn’t so sharp and fragile-looking.
With those changes in place, I started printing, but pieces kept peeling/detatching, resulting in some… spectacular failures that often involved massive misalignments. I made it through four usable batches of two pawns each, but a couple were damaged during removal (my sister and I had similar ideas involving channel locks on batches 3 and 4, respectively).
I printed a bishop, knight, rook triplet and the 10% infill I had been using did not support their flat tops. The bishop was usable, but a little warped on the base. Nevertheless, all three had performed decently, so I bumped it up to 15% infill and tried printing the back row pieces minus knights. Print failure after print failure. Small brims curled on the first layer, even with a high temperature first layer trick I tried.
Finally, I programmed some brims so big they would touch, I also tried wiping the bed with some acetone. Another print failure, but this time only because it stopped extruding after a beautiful, no-curl first layer. I took the printhead out and cleared out a clog, only for it to clog at least one more time. Eventually, I traced the source of the crud not from my spool of filament, but to the e-step motor assembly and even fashioned some tools out of my failed prints to navigate the tight quarters in the mechanism to clean it out. The next print came out nicely.
I knew from the beginning I wouldn’t be happy playing with K’s for knights. Where most of the pieces were just the heads of a more traditional set those knights – YUCK! I appreciate the need for a simpler geometry for small prints, but K is for king in Chess notation where N is for knight. I found my way around Thingiverse to a decent knight designed to be printed without supports [2]. It was a slight adventure putting its head onto a base like the other pieces, but a doable challenge nonetheless. I printed two up to complete the army.
Filament Change and the White Army
I stayed up late to get the knights off as soon as possible and get the white army printing so they would be done before my writeup (an estimated 14 hour printjob). I should have slept on it. Mistake 1: using the firmware’s unload feature; the plastic overheated and stretched off inside the printhead, denying the cleaning filament admittance. Mistake 2: disassembling the printhead while it was on, in a shadow – I snapped two fan blades in successive attempts to engage with a bolt. Within ten minutes, I had found a replacement set of fan blades [3] and quadruple checked the counter clockwise variation was the file I needed. I printed it, enduring the much louder fan as it choked out one last print.
In the morning, my father advised we pass on gluing the original blades back on in the hopes of printing a better set of replacement blades. I clipped the remaining blades and used the fan itself to sand the nubs smooth. My father glued the blades on and we had to squish the fan’s housing to correct for Mistake 3: clipping one of the fan’s three spokes. I printed a Benchy tugboat to satisfactory results.
After all that drama, the white army came out usable with one knight warping a little and one pawn nicked during removal. I plan on adding a couple extra queens in each color because I know from experience that they make for more exciting endgames.
Takeaway
Don’t work on machines while tired, or in the dark. The fix I found is only a patch job until I can buy an upgraded replacement. It’s not as balanced as one made to factory standards, but it is good enough for decent prints on a temporary basis.
Final Question
What self-inflicted accidental damage have you caused by a series of dumb mistakes?
I look forward hearing your answers on in the comments below or on my Discord server, where I sometimes share exclusive nuggets that didn’t fit into the main post.
Works Cited
[1] Raukk, “Travel #chess,” thingiverse.com, March 22, 2012. [Online]. Available: https://www.thingiverse.com/thing:19754/comments. [Accessed June 13, 2022].
[2] Zarlor, “OpenSCAD Chess Simple Printing,” thingiverse.com, Jan. 26, 2019. [Online]. Available: https://www.thingiverse.com/thing:3381939/files. [Accessed June 13, 2022].
[3] CreativeTools, “Cooling fan replacement blades,”thingiverse.com, Nov. 19, 2013. [Online]. Available:https://www.thingiverse.com/thing:186979. [Accessed June 13, 2022].