We are absolutely ECSTATIC with this test. This is the 5th month of controller testing- with this round we have solved its biggest problem and inadvertently improved another feature many times over. First- we’ve achieved the full range of vacuum: 0-21 in Hg. We’d previously only achieved 16 in Hg.
In doing so, we also reduced the automatic vacuum maintenance hysteresis to a remarkably fabulous less-than 0.5 in Hg swing. (Our calculations predicted this, however when we were only achieving a hysteresis of 2 in Hg we figured it was unexplained mechanical loss and accepted it. Turns out the cause was the same as our loss of total range.)
The controller has only a few minor touch up items remaining- the fast-application valve needs to be resprung, and the steam valve seal needs to be reworked. The quadrant needs travel limit stops and detents, and the valve will then get one final set of internal adjustments.
Please note this controller is based on US Patent 241,334, issued to Fred Eames in 1881. We used his basic design: a diaphragm which compares vacuum level to a compression spring- however we did make several improvements to improve functionality, sensitive component protection, and compactness.
We are now proceeding fully on construction of two prototype “bellows cylinders,” based directly on US patent 228741.
Tickled pink with this controller, we are!!
Happy New Year,
Jason
