V-belt replacement

[garys]

Assuming you have the correct length and width belt, then setting the high speed according to the book with the belt 1/8" should set the sheaves to the correct position.

[dusty]

Something to ponder:

Belt Check for Forum.xlsx

(18.99 KiB) Downloaded 1637 times

This chart results from some real world measurements combined with some spreadsheet expansion of that data collected.

[JPG]

Nominal belt length is NOT the od, but something between the od and the belt id. It is the 'effective' length when running over a pulley. I goofed when I said 25.5. I do not know where that first 5 came from(s/b 6).

Yes the reeves drive will accommodate a narrower belt(like when it wears), but the resultant speed range will be altered. i.e. for a given setting of the control sheave, a narrow(worn) belt will ride lower in the idler pulley. The motor pulley will also be responding to the narrower belt by allowing the floating sheave to be closed more. This will result in the belt riding higher in the motor pulley. The resultant speed will be an increase over that attained with the wider(new) belt.

[dusty]

Yup. I agree with all of that. That simply means that when you turn on the Shopsmith and set it to saw speed (as an example) you don't really know what the speed is. It is somewhere in the general vicinity of the recommended speed.

This is true whether you have a brand new belt or one that is somewhat worn and frayed.

Further more, for discussion here or for work in the shop, the "measured" od of the drive belt is as good as any other number you might use for calculations. "Effective" length is to be measured at that location where the support fibers are located. Since that can not be determined without manufacturing specs for 'that specific belt' I use the od.

My belts all measure 26 3/4".

[roneg]

Um..Iz just wondering what might cause a thing like this to happen.

[dusty]

Assuming you have the correct length and width belt, then setting the high speed according to the book with the belt 1/8" should set the sheaves to the correct position.

I agree BUT why do we all seem to believe that the belt should ride 1/8" below the rim of the sheave? Are there consequences if it rides closer to the rim? Like say the belt and the rim are at the same level?

To avoid confusion...let us assume that we have the proper belt installed and it is in excellent condition (brand new from Shopsmith).

[roneg]

Got some time to go down to the shop and remove the belt. Couple of things I noticed;
First... there is no access from the logo (no hole) on my SS. It is as old as me! So removing the "pork chop"(86) from the control sheave (110) ..tricky. Good thing I was in a wood shop..plenty of various sizes long sticks.

Second... both the idler sheave(109) and floating sheave(117) seem stuck to their respective shafts.

[JPG]

The idler sheave(109) is NOT supposed to slide on the idler shaft(105).

The floating sheave(117) is under a strong spring(116) tension. However it can be moved by hand. That said if it IS stuck it likely is causing your problem.

The control sheave(110) needs to be positioned at the 'fast' position(closest to the quadrant(86 aka porkchop) in order to remove the clip(attached to the control sheave).

No access hole, therefore you have an "A" headstock. You may also have movable sheaves WITHOUT an oil hole and it likely has not been adequately lubricated(oiled) these past 60+ years.

So your immediate task is to get it lubricated so the movable sheaves do so easily. Then that belt MAY track correctly. I dare say the floating sheave is starved for oil.

Be careful using the online exploded view on line. Your greenie has several differences. I strongly suggest you download a greenie manual from Everitt's google drive.

[roneg]

Thanks JPG,
Not real familiar with the innards of these "marvels of modern man" yet!
What you recomend for lubrication of the sheaves?

[JPG]

Thanks JPG,
Not real familiar with the innards of these "marvels of modern man" yet!
What you recomend for lubrication of the sheaves?

#10 MACHINE oil. 3 in 1, sewing machine oil, turbine oil, Recommend any with a 'zoom' spout extension. If yours does not have the oil holes, apply it to the shaft directly where he sheave slides. Likely you will need to get in between the sheaves.