Slow to gain speed

[jms]

Yes I think Nick cheated on that one!

Tomorrow, hold the idler sheave in your handwith the output shaft pointing towards the floor. Whack the control sheave end with a short 2x4. That should get it moving. May have to reverse a few times. You do have the copper colored hair pin clip removed! Located on the shaft deep inside the idler sheave center. Making sure we be referring to the same 'clip'.

Yes I do have the copper colored clip removed!!

I tried this morning, using the method you mention except using a rubber mallet -- still no movement in the sheave in either direction. I suppose I'm going to need some penetrating oil.

I'm wondering if the current idler shaft/bearing should be replaced or not. There is no measurable run-out or wobble in the bearing, however the bearing does slide maybe 1/32" side to side, i.e. directionally parallel to the shaft.

[dusty]

Just making sure. I believe you have said that you have all of these parts:

[JPG]

A 2x4 will have a greater(but still gentle) shock effect than a rubber mallet.

Actually a brass or copper mallet would be better.

[jms]

After complete headstock and drivetrain disassembly, cleaning, inspection, lubeing and reassembly, with all mechanical components proving quite serviceable, I still have the slow to start problem but I've narrowed it down a bit.

Basically if I shut the machine off in a speed above around the Dado speed on the speed dial, the unit will have a hard time getting up to RPM when I turn it back on. The position of the sheaves and drive belt are really the only varying factors here, and basically my motor doesn't seem to have enough "ooomf" to get up to speed when it has to work hard from a dead stop when starting from this position or a faster speed setting, i.e. when the floating sheave is at its narrowest point and the drive belt is at its largest size at the floating sheave, requiring more torque to start from a dead stop.

Simple workaround, always stop the unit with the speed setting in the saw/joint or lower. This solves the issue 100% of the time.

Permentant fix - I'm not familiar enough with the motor to know if there is a *replaceable* part (starting capacitor, etc) that I can change out that will mitigate the problem without replacing the entire motor.

[JPG]

I assume the motor turns freely with no belts attached(spins easily by hand).

If so we have essentially exhausted all the mechanical causes.

That leaves electrical causes.

Are you attempting to run the SS with an extension cord?


Is the receptacle far from the breaker panel?

Is it on a dedicated 20A circuit?

Are there other things plugged into that circuit?

Finally are all the terminals(power cord/switch) in good condition?

[dusty]

After complete headstock and drivetrain disassembly, cleaning, inspection, lubeing and reassembly, with all mechanical components proving quite serviceable, I still have the slow to start problem but I've narrowed it down a bit.

Basically if I shut the machine off in a speed above around the Dado speed on the speed dial, the unit will have a hard time getting up to RPM when I turn it back on. The position of the sheaves and drive belt are really the only varying factors here, and basically my motor doesn't seem to have enough "ooomf" to get up to speed when it has to work hard from a dead stop when starting from this position or a faster speed setting, i.e. when the floating sheave is at its narrowest point and the drive belt is at its largest size at the floating sheave, requiring more torque to start from a dead stop.

Simple workaround, always stop the unit with the speed setting in the saw/joint or lower. This solves the issue 100% of the time.

Permentant fix - I'm not familiar enough with the motor to know if there is a *replaceable* part (starting capacitor, etc) that I can change out that will mitigate the problem without replacing the entire motor.

I assume that you have had the motor out on the bench and that it comes to speed properly with each and every restart. If you have not done this, I suggest that you do. A no-load test doesn't reveal everything that could be wrong but it is always my "first step" in isolating motor problems.

As for your start/stop speed control solution, if you are going to do this, go all the way to low speed before you turn off.

I, however, believe that to be only a bandaid to cover the real issue. It seems to me that there has to be something causing the motor to start up differently even "from time to time". This should be a very repetitious process.

I do experience slow startups whenever it is cold and the machine has set idle for some time. I theorize that this is due to stiff belts. Once I run the machine up two or three times, that symptom seems to go away. I use my Mark V on a dedicated 120v/15amp circuit and I do not use an extension cord. I have, however, lengthened the power cord on my Mark V to about 14' using 14ga cord. I believe a standard Shopsmith power cord is 14ga. My handy pocket guide to wiring says I should be able to go up to 30' in length, under these conditions, without experiencing significant voltage drop.

[JPG]

Does your 'pocket guide' allow for extreme(normal) startup current?