tim0625 Posted March 25, 2012 Report Share Posted March 25, 2012 We're dealing with an old Craftsman contractor table saw...1 1/2 or 1 3/4 HP; 110v. I've done a little work on it today resetting the blade tilt stops and oiling the adjustment screws with 3 in 1 oil. In the process, I ALSO oiled the arbor shaft bearing. When I fired the saw up, the beast was unleashed!!! It had more RPMs than I've ever heard from a saw...any saw....I understand maybe the bearings were old and dry and probably worn out though the shaft does not have any play at all. This saw was in a shop fire years ago and got hot, but not too bad but maybe hot enough to compromise the sealed, arbor shaft bearings a bit. Maybe the oil could penetrate the formerly sealed bearings some and loosened things up a bit and now, it's spinning more freely than in years but guys, I've been around table saws all of my 52 years and I'm talking about crazy RPMs. I also smell the belt slipping a bit on start up. So I carefully approach the spinning beast with my hardhat on that has the drop down face shield and carefully cross cut a 5/4 x 3 with my miter and it... cut... like... butta.....UNTIL... half way through the cut, the thin kerf blade began to wave back and forth like a belly dancer's belly. I removed the blade and rechecked the mounting and it's all good. Checked the stopped blade - it's flat. Remounted the blade, cut another crosscut and it still waves at me. It's like the 110v motor was suddenly plugged into 220v. But that's not the case, I checked the outlet with other tools that ran fine. I'm really at a loss to explain and at this point, scared to use it. Could the motor be doing something squirrely and shorted out somewhere and increased the RPMs? Thanks Tim Quote Link to comment Share on other sites More sharing options...
tim0625 Posted March 25, 2012 Author Report Share Posted March 25, 2012 What did he say???? I got ya hhh. Thanks Nope...weren't gonna use it until the Houla dancing stopped. I was thinking that thang could become a 40 toothed " No says I..... I solved the problem....now I'm interested if someone can come up with the answer. I leave the post up because I think it could happen to most any tablesaw so we'll all learn together. Quote Link to comment Share on other sites More sharing options...
fransikaner Posted March 25, 2012 Report Share Posted March 25, 2012 Sounds like your flux capacitor prematurely discharged?????... Quote Link to comment Share on other sites More sharing options...
DennisL Posted March 26, 2012 Report Share Posted March 26, 2012 Sounds like your flux capacitor prematurely discharged?????... Did you use more than 1.21 Gigawatts!? Also, stainless steel body? Quote Link to comment Share on other sites More sharing options...
Jfitz Posted March 27, 2012 Report Share Posted March 27, 2012 I solved the problem....now I'm interested if someone can come up with the answer. I leave the post up because I think it could happen to most any tablesaw so we'll all learn together. Did you mix up the pulleys when you put it back together? Quote Link to comment Share on other sites More sharing options...
tim0625 Posted March 27, 2012 Author Report Share Posted March 27, 2012 HHH had some good ideas...I didn't know that something like oil could (electrically) cause a motor to increase in RPMs. But alas....the problem was not electrical. It was mechanical and I did not dissemble the pulleys from the motor or arbor shaft. I think of Tim the Tool man Taylor....now HE may have been using gigawatts! The Answer is: I reinstalled the belt over the motor pulley and instead of putting the belt over the arbor shaft pulley, I missed the pulley and put the belt on the inside of the pulley over the arbor shaft itself. The arbor shaft is maybe 1 inch in diameter whereas the pulley is maybe 2 or 2.5 inches. It changed the ratio to the point that the blade was spinning very fast - I'm guessing maybe 6000 RPMs or more. When I would start the saw, the belt would slip on the shaft until the blade reached full speed so that's where the smell came from. I think that many contractor saws could have the same potential. I was like HHH - I was testing everything I could think of when in fact, my dad's wisdom is still true - "Son, always look for the simple things first. Most of the time, the problem will be something simple". Although, I still wonder what caused the blade to wave back and forth like a belly dancer's belly? I guess it could have disintegrated? Thanks for looking. Tim Quote Link to comment Share on other sites More sharing options...
TimV Posted March 27, 2012 Report Share Posted March 27, 2012 The Answer is: I reinstalled the belt over the motor pulley and instead of putting the belt over the arbor shaft pulley, Darnit! I didn't get a chance to respond. That was going to be my answer! And fyi, there is no way a motor can increase its speed electrically. If a motor has "poles fail", the connection scheme will not allow that and the motor will fail all together. Decreased friction will not speed the motor up faster than the design speed. The only way a motor can increase its speed is through pulleys (or shaft) like you found out or adding an inverter to increase the frequency (but that's another story all together). The blade probably wobbled because it was a thin kerf, less material and at a higher rpm, the teeth created more windage and the thinner plate couldn't resist the forces applied by the windage. Quote Link to comment Share on other sites More sharing options...
suiciedchild Posted March 28, 2012 Report Share Posted March 28, 2012 Blah Blah Blah, smarty words and stuff , Blah Blah Blah, more words. Quote Link to comment Share on other sites More sharing options...
tim0625 Posted March 30, 2012 Author Report Share Posted March 30, 2012 Smarty words....das funny....all I know is when that thin kerf blade began doing the syfy wave, I about left the shop! Ningy star! Quote Link to comment Share on other sites More sharing options...
TimV Posted March 30, 2012 Report Share Posted March 30, 2012 I remember buying a half dozen ninja stars when I was a kid. That was back in the mid-80's when the ninja thing was cool. Those stars were awesome, I threw them at every tree and piece of wood I could. I never sharpened them, but man, if I did....... Quote Link to comment Share on other sites More sharing options...
suiciedchild Posted April 2, 2012 Report Share Posted April 2, 2012 Ninja stars are awesome, I once watched a guy throw a table saw blade through a wall (he was a little upset) , it went into the next wall in the following room, where it hit a stud and stopped. I think I would have just carted my TS outside and put a "free" sign on it with a liability waiver if it started spinning and waveing like that. Quote Link to comment Share on other sites More sharing options...
QuebecSti Posted August 14, 2012 Report Share Posted August 14, 2012 And fyi, there is no way a motor can increase its speed electrically. If a motor has "poles fail", the connection scheme will not allow that and the motor will fail all together. Decreased friction will not speed the motor up faster than the design speed. Well that leaves me puzzled then.... This issue happened to me over the weekend. I didn't do anything to the saw. I was cutting and then it all started... It went from regular speed to extreme high RPM. I turned it off. Burnt smell... I left it alone to cool off a bit, turn it back on, same thing at power on. Turned off again, waited longer, turn on again, was fine...... and started again few minutes later. Didn't touch it since. I had a dado stack blade 1/4 inch... so no belly dance for me.... I suspect humidity.. is it possible? I might have to bring it in for repair... It's a direct drive ( no belt... ) thanks for your input and sorry to wake up an old topic... - Eric Quote Link to comment Share on other sites More sharing options...
tim0625 Posted August 17, 2012 Author Report Share Posted August 17, 2012 Better ask HHH or someone who understands motors. I connect the two wires. It either spins or waves a white flag. I discount the humidity theory just because I've never heard of it in 5 decades even with motors exposed to the elements. I think something's melted, fused, discharged, flux capacitor-ed....call Doc!! I'll bet he knows!! Quote Link to comment Share on other sites More sharing options...
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