Round Nixie Watch - Part Six

After all this was designed in June 2004, I took the case design files to my local machinist. He quoted four weeks delivery of some prototype cases. I gave him a deposit. Four weeks went by. No cases. He was having trouble getting his friends with CNC lathes to halt production to do his prototypes. So he went out and bought a CNC lathe at auction. It took a lot of work to get going, some of which was my RS-232 interface assistance. Still no cases. The lathe threw its toolholder! He worked on it some more, then gave up and bought another lathe at auction. It almost worked, but the spindle pulley was loose. He rebuilt the spindle pulley. Still no cases. 

After five months of this, I went to the Internet and found a machine shop called QuickParts. They promised two-week turnaround. I bit. Two weeks later, I had my watch cases. 

I built three prototypes in cases, each with a different coating on the metal. One is still raw aluminum. The second is black hard anodized. The third is clear hard anodized. I kept the clear-anodized one and gave the others to friends

Then I found that the 8 digit in the right tube failed on several watches. The 8 sometimes flickers, sometimes doesn’t display at all, and sometimes works normally. This indicates a problem with the MAX6931 chip in this application. I couldn’t see any obvious fixes.