Re: suggestions on rotary valves

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Posted by John Swensen on June 24, 1999 at 14:11:31:

In Reply to: suggestions on rotary valves posted by Bill on June 23, 1999 at 19:41:51:

There has been some very useful advice, so far.
If I had to guess what the problem was, it would be that the bearings are on the tight side and the oil you are using on the spindles (for the bearings) is a bit too thick (viscous). One way to tell would be to remove the linkage and the stop arm and try to
spin a rotor with your fingers. If it feels sluggish there the linkage is not the problem. Unless you can feel and/or hear metal-metal contact (scratching sound), the rotors are not rubbing on the casing and do not need lapping.
You could try using piston valve oil on the spindles as an experiment, or you might try backing off on the back plate (the spindles are tapered, so moving the back plate further back should open up the clearances).
I assume that you ran the corner of a rag through the spindle bearings when you cleaned the valves, and maybe even scrubbed them out using a mouthpiece brush, in case they were gummy inside.

As for springs, they are very easy to wind yourself out of music wire, if you have the ability to drill a hole in a piece of metal and maybe use a file. Bake for 1 hour at 500 degrees F., and they are ready to try. By varying the number of turns, the diameter of the music wire, and the initial "set" of the spring, you can get quite a range of stiffness.
I can't find a link to an excellent spring-winding site (I'm at work), but I'll try to
look it up at home and post the link.

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