Well That Was Interesting

[crokett]

I was using the band saw tonight to do some final testing. Good news is the only tweaks it needed were adjusting the guide and the tension. Blade tracks well on the wheels, no drift I could see, etc. I was in the middle of a resaw, there was a click and then the blade wouldn't move if it was under load cutting. At first I thought something happened to the motor but decided to work backwards. I pulled the covers and turned the wheels by hand, that worked fine. Pulled the belt cover off to check the belt and something fell on the floor. It was the key from the motor pulley. I could spin the pully on the motor shaft. Without the motor turning. Put everything back together, tightened the set screw way down and now it is cutting just fine again.

[Pappy]

Simple, zero cost fixes are always nice to come accross!

[Uncle Cracker]

If that happens again, check to see that the key is the right size for the keyway. If it's been replaced with one that is too small, it may just rattle around in there until it falls out... again.

[cabinetman]

If that happens again, check to see that the key is the right size for the keyway. If it's been replaced with one that is too small, it may just rattle around in there until it falls out... again.

That is a possibility. Also, check to see if there is a machine screw in the pulley (for the key). That could be missing. At least you found out the pulley wasn't frozen to the shaft.
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[Black wallnut]

That is a possibility. Also, check to see if there is a machine screw in the pulley (for the key). That could be missing. At least you found out the pulley wasn't frozen to the shaft.
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I'll bet dollars to donuts that the "set screw" Davy tightened is exactly what you refer to. Yes sometimes it helps to read and understand the OP prior to posting.

[tommyt654]

If it was a loose set screw, put a little nail polish on it before tightening it back up as this will help it hold it in place and not loosen ,If its simply a loose key ,Ditto

[cabinetman]

I'll bet dollars to donuts that the "set screw" Davy tightened is exactly what you refer to. Yes sometimes it helps to read and understand the OP prior to posting.

Thanks for pointing that out. Sorry to have troubled you to remind me of such a mistake. It was early when I posted, coffee wasn't ready, dogs wanted to go outside.
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[woodturner]

If it was a loose set screw, put a little nail polish on it before tightening it back up as this will help it hold it in place and not loosen ,If its simply a loose key ,Ditto

Another option would be thread locking compound - Loctite is one brand. It's available in different strengths, from light to "permanent". HF carries a brand available in small bottles at reasonable cost.

Another thought is that keys do wear - they are intentionally soft metal, so they will shear to protect the motor. I usually replace the key if I think there may be a problem - they are inexpensive and readily available.

[crokett]

What I left out was looking the key over carefully to make sure it was not damaged. It was tight getting it back in, so I think it was the right size. I think it was just a loose set screw. My first thought was that I'd I'd blown the motor or something.

[woodturner]

I think it was just a loose set screw.

Sounds like the key is fine.

If you continue to have a problem with the set screw loosening, one "machinist's trick" is to use two set screws, each half the length of the original. Put the first one in, tighten it down securely, and then install the second one.

It's the same concept as installing two nuts on a bolt and tightening them against each other - tightening the set screws against each other makes them less likely to loosen.

Depending on the pulley, though, you may not have enough thread length in the pulley to do this.