I removed the drive pulley from my Power Pro motor while I was investigating a scraping noise on startup. After I got it off I realized there was a top and a bottom, but I don't know which is which. The ventilation hole openings are larger on one side than the other (1/2" vs. 5/8"). Also, the side with the smaller openings has a chamfer on the edge of the hole the motor shaft goes through. Looking at a stock photo I found on-line it looks the small opening side with the chamfer is supposed to be on the outside.
Can anyone confirm the correct orientation?
I thought the size difference might be designed to induce an air flow through the holes when spinning, but testing with a strip of paper while running showed both orientations tended to pull the paper into the holes, so not sure why they are different. Any ideas?
PowerPro closeup.jpg (46.94 KiB) Viewed 1157 times
Large opening.jpg (149.47 KiB) Viewed 1157 times
Small opening with chamfer.jpg (173.62 KiB) Viewed 1157 times
1985 Mark V upgraded to 520 PowerPro. Shopsmith cast iron table bandsaw, jointer, belt sander, and 60's vintage 610 jigsaw SPT's. Makita 2040 15" planer, JessEm Mast-R-Lift II router table.
In the SS cutaway picture I don't see the snap ring outside the pulley, which mine has. My motor has the 5/8" holes on the outside. I'm pretty sure this is correct, as the chamfer and snap ring seem like an unlikely combination.
Now I'm really curious if the earlier ones did not have a snap ring and it was added at some point. I have always felt that the pulley position on mine wasn't ideal and the belts did not run true even with the pulley maxed out against the snap ring. I modified my motor mounts so that I could adjust the motor and pulley position and the belt could run true.
Thanks David. That was my initial guess until I saw the stock photo since the chamfer on the inside surface would make it easier to slide the pulley on the shaft. I noticed the missing snap ring as well in the stock photo (my motor has a snap ring above and below the pulley with room to adjust the pulley position up and down. I’m wondering if the opening size difference is just the result of using a snubbed nose conical milling bit to cut the holes rather than some engineering feature.
- Steve
1985 Mark V upgraded to 520 PowerPro. Shopsmith cast iron table bandsaw, jointer, belt sander, and 60's vintage 610 jigsaw SPT's. Makita 2040 15" planer, JessEm Mast-R-Lift II router table.
I think the tapered holes has to do with mold release(assuming it ia a cast part).
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Goldie(Bought New SN 377425)/4" jointer/6" beltsander/12" planer/stripsander/bandsaw/powerstation /Scroll saw/Jig saw /Craftsman 10" ras/Craftsman 6" thicknessplaner/ Dayton10"tablesaw(restoredfromneighborstrashpile)/ Mark VII restoration in 'progress'/ 10E[/size](SN E3779) restoration in progress, a 510 on the back burner and a growing pile of items to be eventually returned to useful life. - aka Red Grange
JPG wrote: ↑Thu Oct 12, 2023 3:58 pm
I think the tapered holes has to do with mold release(assuming it is a cast part).
and question answered:
DLB wrote: ↑Thu Oct 12, 2023 1:13 pm
My motor has the 5/8" holes on the outside. I'm pretty sure this is correct, as the chamfer and snap ring seem like an unlikely combination.
Thanks guys!
- Steve
1985 Mark V upgraded to 520 PowerPro. Shopsmith cast iron table bandsaw, jointer, belt sander, and 60's vintage 610 jigsaw SPT's. Makita 2040 15" planer, JessEm Mast-R-Lift II router table.
