Q. I am having trouble with the saw blade on my table saw loosening after a short time. It happens when we install a new blade....that is, the nut becomes loose. What should I be looking for?
A. I can only give you some possibilities. It would be much easier if I were there in person. In any case, a nut does not need to be torqued down with lots of pounds and should not loosen, but will tighten itself with use. Do not over tighten when first installing.
First, maybe the saw shop has a coating or lubricant on the blade that needs to be cleaned off. This is because the nut is held on by friction, so lubricants are undesirable. In fact, if this is the issue, you will also need to clean the whole assembly: washers, threads and nut. (I assume that you did not lubricate things yourself.)
Second, perhaps you have a washer on the nut side that you forgot to reinstall. Or perhaps this washer is dished and you put it on backwards--the rim of the washer should contact the blade first.
Third, do you have an abrupt stopping mechanism? If so, this sudden stop can exacerbate or potentially loosen the nut if things are not perfect. Perhaps a vibrating bearing will also contribute. However, if items #1 and #2 are OK, then this stopping or vibration would not be an issue.
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