Motor “lags” or “forgets” where it’s at when I crank up the speed.

[Zipp08]

This is the problem I’m having :
When I fire up the ShopSmith, it runs good. As I slowly crank up the speed, about half way through the dial, the motor stops climbing RPMs. At this point I have to quickly crank back the dial slightly in a shocking motion in order for the RPMs to get back on track, then I have to “baby” the dial as I turn it to the right to increase the RPMS. From the half way point on the dial, to about 3/4 full speed, is when the motor will stop increasing RPMs forcing me to “baby” the dial and making me turn the dial “left and right left and right” in a chattering motion or in a extremely slow motion, in order for the RPMS to stay on track. So from the half way point, to about 3/4 of the dial, is where you have to be careful increasing the RPMS.

I am new to the ShopSmith mark v. Before I received the unit, it had been hardly used and stored away in a shed for over ten years. When I received the unit, I wrapped the entire machine in tarp, and stored it under a carport outside for 5 years(so this ShopSmith sat for like 15yrs with little to no use). From my point of view(I’m a noob) all the bearings and belts n whatnot are in great condition. I’ve had one person tell me maybe the motor needs to be rewound? Considering all the inner components are in good condition. Maybe a belt is loose?

[DLB]

I think the likely cause is the 'floating sheave' on the motor shaft is not responding well to speed change. There are several possible causes but start with lubrication of the sheave. The control sheave on the idler shaft should also be lubricated. Unless your machine is very old there will be small holes in these two sheaves for lubrication. There are numerous threads on lubrication, best not to repeat all that here.

If lubrication does not solve the problem, come back here for more suggestions.

- David