|HP 97 clutch repair methods compared|
Message #1 Posted by Ed Sowell on 18 Apr 2010, 3:23 p.m.
I'm reading up on the clutch problem since my card reader was a bit noisy after replacing the drive wheel rubber.
Although a fair tug was needed to pull the clutch off the motor shaft when I first did it to check the condition of the clutch, I now find it comes off quite easily. So, the question is what to do about it.
There seem to be 4 methods in earlier posts, listed below. Clearly, for either of the first 2 to be considered the original clutch material must be in good condition and just slipping a bit, like mine.
1. Superglue between the motor shaft and the original clutch material. (various people have suggested this)
2. A small bit of cling-wrap between the motor shaft and the original clutch material. (Rafa, Spain)
3. Replacing the original clutch, aluminum sleeve and all, with a piece of insulation pulled off of a solid conductor electrical wire. (Bernd Schmeling)
4. Removing the original clutch material from the worm gear shaft and the aluminum sleeve and replacing it with ordinary household silicone adhesive. (described in detail by Johnny Nestor)
Method one is clearly the easiest, but it has been criticized for fears of serious damage under some circumstances if no slippage at all is allowed. Method 2 seems tedious and perhaps not durable. I worry about method 3 because the aluminum sleeve is omitted; if it's not needed I wonder why HP put it there. I like method 4 because I believe that's pretty much what HP did in the first place, i.e., molded the two shafts together with a rubbery material inside a metal sleeve to provide lateral rigidity. However, it sounds very messy and I wonder how hard it is to get perfect centering (or good enough).
So, with that background here's my question: If the clutch material should not be bonded to the motor shaft in method 1, why is it OK to do so in method 4? In both cases the bulk of the clutch material will provide the wanted vibration isolation.