Today I disassembled the Edwards Difstak 63. There was a lot of deposits of blackened oil built up inside, so I thought I would use oven cleaner to clean it up. This proved to be a big mistake, the over cleaner dissolved the metal… I had assumed it was stainless, but perhaps it was aluminium? The top of it is now massively corroded and I suspect has lost several important dimensions. It might still work, but I don’t want to take the chance.
To resolve the issue, I’ve drawn up in CAD today (Fusion 360) a replacement part. I’m 3D printing it to check fit, and then will ask a prototyping shop to create a stainless version for me. Likely quite an expensive mistake!
In other news, quite a few deliveries have come in for the various parts.Vacuum system-wise things are progressing well, with pumps/adapters/sensors now received. On the computer control, the Raspberry Pi is talking happily to the pressure sensors, so I will have feeds of pressure data.
One of the most significant things to think through is HV power supply. There seem three basic choices; 1) build a heavy duty transformers and rectification under oil, 2) build a switching power supply, 3) purchase a supply (either fully to spec, or not quite to spec and modify it). Lots of research to do on which option to go for…