It took a lot of time to cut all the aluminum pieces (16 pieces X around 2 hours for each piece). Fortunately the wood was simpler. I used the bitbreaker mode with Mahogany wood settings from otherplan website (0.05″ depth instead of 0.003″) which let me speed it up at least 15 times faster. The rpm was down from 15k to 10k, it made the operation kind of less noisy.
The only problem was sticking the wood to the spoilboard- I had to be extremely careful with wood and spoilboard surfaces before mounting it on with a two-sided tape.
I engraved 0.145″ outline rectangle on the tiles, it allowed me to have precise and identical shapes. Although they were all rectangles, it is practically very difficult to device a system that cuts exact rectangles. Chop saw, thread saw, band saw etc. tend to develop some error over time, and it’s difficult to get 90 degrees cuts. The outline engraving was a nice trick ; I sanded the tiles till those outline marks. The final tiles arrangement looked like this:
The aluminum pieces snapped perfectly in the corresponding places, there was 0.006″ tolerance:
When a few other students used the othermill, I took some brass and aluminum and turned it into this:
Basically I made a hole in brass, measured it with calipers, turned aluminum to a diameter little larger than the hole, and pressed the two together in the arbor press. Then I turned the composite cylinder on lathe again, faced it till it reached the point where the two metals had no gap between them, and cut it using a parting tool. Next I quickly made an acrylic stencil on lasercutter, fixed the metal piece in it and put it on othermill bed. The stencil provided a great reference in aligning the drawing.
Ultimately it became a compass for the map-
Next I aligned all the tiles, tested the alignment with a few aluminum pieces, and glued all tiles together to a flat 12″ X 15″ ply:
I left it to dry overnight. Next morning I fitted all the metal pieces into engraved cavities and masked them with tape. I applied minwax dark walnut finish to the oak tiles, and then made a frame around it using the same oak. Later I applied a coat of polyurethane on everything (frame + tiles), with the masking still on. I still had to use some turpentine to remove a few walnut finish stains from some metal pieces, where the masking didn’t do a great job.
And here’s the final map!