Power surging

[JPG]

I don't know how that happened and I didn't know it happened to I came back to read Dusty's comment. I have deleted my duplicate.

Ya clicked on submit, then either became distracted and weren't sure you had clicked it, or it took so long to respond you weren't sure you had clicked it, or it took so long you forgot you clicked it.

Not an uncommon occurrence for me! I usually notice it right away though!:D

Blame it on 'I Been Moved!'

[SDSSmith]

I have had machines that the speed has "hunted" or surged on start up with the speed dial set up in the "Saw" range. The hunting/surging stopped as I dialed the speed dial down. That would seem to be a voltage problem to me. The flickering lights at the same time seem to support the voltage concern.

[JPG]

I have had machines that the speed has "hunted" or surged on start up with the speed dial set up in the "Saw" range. The hunting/surging stopped as I dialed the speed dial down. That would seem to be a voltage problem to me. The flickering lights at the same time seem to support the voltage concern.

You forced the belt towards the center of the motor pulley when 'lowering' the speed setting.

If the floating sheave on the motor pulley was sticking at a higher speed setting and the control sheave is set 'higher', then the belt would be 'loose' and as such would tend to jump in and out on the pulleys(both the idler and the motor pulleys). This would cause speed varying and a torque load 'jumping'(increase when the belt 'caught'). It would also cause 'stalling'(belt slipping). The output shaft would be stalling, but the motor speed would not.

[SDSSmith]

You forced the belt towards the center of the motor pulley when 'lowering' the speed setting.

If the floating sheave on the motor pulley was sticking at a higher speed setting and the control sheave is set 'higher', then the belt would be 'loose' and as such would tend to jump in and out on the pulleys(both the idler and the motor pulleys). This would cause speed varying and a torque load 'jumping'(increase when the belt 'caught'). It would also cause 'stalling'(belt slipping). The output shaft would be stalling, but the motor speed would not.

This was not the case, the sheave was not and is not sticking. I reduced the torque requirement/voltage requirement when I lowered the speed setting.

[JPG]

This was not the case, the sheave was not and is not sticking. I reduced the torque requirement/voltage requirement when I lowered the speed setting.

So what was causing it? Seems severe for electrical voltage fluctuations caused by changing current due to torque required under no work load conditions.

The 'flickering' lights does indicate an electrical load fluctuation. The question is, is that a cause or a symptom?

[mickyd]

Thanks for all the replies. As to the power surging, once running, the motor slows, then speeds back up. The change from high to low is over about 2 seconds. The belts were in place.

I am guilty of not having oiled regularly. I doubt that's it, though. When I removed the belts, the motor shaft rotates freely. When I run anything (1/4" pine strip) into the blade, it bogs down for a few seconds, then the breaker trips. I haven't run anything through the blade since putting in the dedicated line but the motor's acting the same as it had on the shared circuit.

I don't notice the lights flickering and my skill saw works fine.

I don't know how the motor was rebuilt. It came from someone who only works on Shopsmith. I ran into him on a different Shopsmith forum - I think in 2003.

The motor is marked 115V single phase 60 hz 3450 RPM.

I appreciate the help.

For the record........Flckering lights have come into a couple posts after hnderson indicated that wasn't observed.

[JPG]

For the record........Flckering lights have come into a couple posts after hnderson indicated that wasn't observed.

I was referring to Rob's lights!]change [/B]through a thread!

[mickyd]

I was referring to Rob's lights!]change [/B]through a thread!

Hey I have trouble focusing when there is NO CHANGE!!:D