Shopsmith Forums

The motor reaches max RPM as shown in the attachment. Further increasing the speed acctually decreases it. Low end changes very little onece Disc Sand is reached.

Suggestions?

Assuming the speed control and control sheave are behaving, the problem is a sticking floating sheave. It is the weak sister that rarely gets sufficient oiling. It needs to be very free moving so as to maintain correct belt tension.

Thank you. Assuming that is the cause I will assume that this is the fix: I oiled it yesterday, when I discovered the problem. Now I suppose just running the motor and cycling through low and high several times will distribute the oil sufficiently to free it up.

Cycling through the speed range helped the low end which is now spot on. The high end has a peculiar quirk. High end increased from Q to S. When I reach the point where it doesn't increase (S) there is a "skip" or "jerk". Try slowly rotating your hand from left to right and then suddenly rotate it. That's what is happening then continuing cause a speed drop.

db5 wrote:Cycling through the speed range helped the low end which is now spot on. The high end has a peculiar quirk. High end increased from Q to S. When I reach the point where it doesn't increase (S) there is a "skip" or "jerk". Try slowly rotating your hand from left to right and then suddenly rotate it. That's what is happening then continuing cause a speed drop.

So apparently the floating sheave is no longer sticking at the low end. The sheave is positioned out from the motor on the shaft. Oil gets there more easily.

I think the reason the speed falls off is that the floating sheave is sticking(not closing the pulley) at high speed setting. The control sheave opening up(raising speed) not being followed by the floating sheave closing will result in low belt tension and belt slipping - hence the speed fall off.

You need to get the sheave freely moving. Set the speed to slow(motor pulley opened). Get some oil directly onto the motor shaft as close to the motor as you can get it. Do not be stingy with the oil. You can clean up any slung oil after all is well. No not easy to access, but that is life.

Raising to vertical over night may help the oil seep into the problem area.



"S" is where the anti-rattle spring has to traverse the ramp on the back on the speed indicator dial. Added resistance to speed increase should occur there. That is an intentional design 'feature'. The Greenies required depressing a stop release to go above "S". They have a stop rather than a ramp on the back of the dial.