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+-- Thread: 20mm bore pulley? (/showthread.php?tid=7359430)
20mm bore pulley? - ®smpr_fi_mac® - 12-10-2020
I'm trying to put a HF dust collector motor into service powering my belt sander. But it has a 20mm shaft and I can't find anything in that size. Outer diameter doesn't matter to much; I can change the driven pulley to match, though I'd like one close to 2" diameter or so.
Can you guys help?
RE: 20mm bore pulley? - MstrCarpenter - 12-10-2020
I did a quick search, even Grainger was no go. If I were faced with your dilemma I would consider drilling out a 3/4" sheave to 20mm or filing the shaft down to 3/4". I don't happen to have a 20mm drill bit nor the inclination to order one. I do however have many files and a decent micrometer. Might have to file the keyway too, but the shafts are usually quite soft. I think taking off .037 with sandpaper is asking a lot, but I'd use it for the last .005 or so. Of course the files and paper would be used while the motor is running.
RE: 20mm bore pulley? - ®smpr_fi_mac® - 12-10-2020
I thought about drilling out the pulley I have now. I don't care to try sanding down the drive shaft.
I just remembered seeing folks on YouTube turn plywood pulleys on a lathe. I may just give that a try.
RE: 20mm bore pulley? - Timberwolf - 12-10-2020
(12-10-2020, 11:14 PM)®smpr_fi_mac® Wrote: I thought about drilling out the pulley I have now. I don't care to try sanding down the drive shaft.......................
I just remembered seeing folks on YouTube turn plywood pulleys on a lathe. I may just give that a try.
If the pulley has a keyway, you will probably have a problem drilling it...Best to have someone bore it to size on a metal lathe...I would not risk grinding down the motor shaft by hand..Chances are that you will not be able to keep the shaft from going out of round......Making a wood pulley is very doable.
RE: 20mm bore pulley? - EdL - 12-11-2020
Check the Misumi website, they have more shrit than anyone. Actually to much.
Being a Japan based company, their metric selection is unequalled.
Ed
RE: 20mm bore pulley? - Bill_de - 12-11-2020
(12-10-2020, 09:19 PM)®smpr_fi_mac® Wrote: I'm trying to put a HF dust collector motor into service powering my belt sander. But it has a 20mm shaft and I can't find anything in that size. Outer diameter doesn't matter to much; I can change the driven pulley to match, though I'd like one close to 2" diameter or so.
Can you guys help?
John Deere AM121832 V-Groove Drive Pulley - 4.75'' Dia. - 20mm Bore - Steel (phoenix-mfg.com)
???
Also available from Phoenix through Amazon.
How close are the tolerances on the bore? The difference between 20mm and 3/4in is .037402"
RE: 20mm bore pulley? - TDKPE - 12-11-2020
(12-10-2020, 09:19 PM)®smpr_fi_mac® Wrote: I'm trying to put a HF dust collector motor into service powering my belt sander. But it has a 20mm shaft and I can't find anything in that size. Outer diameter doesn't matter to much; I can change the driven pulley to match, though I'd like one close to 2" diameter or so.
Can you guys help?
Why, yes. Yes I can.
2.4" pitch diameter sheave with an A (1/2") belt. Single groove. Ignore the OD, as that has nothing to do with anything other than space constraints.
https://www.surpluscenter.com/Power-Transmission/Pulleys/Split-Taper-Bushed-Bore-Pulleys/3-15-OD-H-Bushing-Single-Groove-Pulley-1-BKH30.axd
20mm split-bore hub that fits that sheave.
https://www.surpluscenter.com/Power-Transmission/Pulleys/Split-Taper-Bushed-Bore-Pulley-Hubs/20mm-Metric-Keyed-H-Bushing-1-2915-20.axd
$15.55 is less than what you'd spend on a machine shop to bore out your existing sheave, but you may have to get a larger driven sheave to keep the ratio you're looking for.
RE: 20mm bore pulley? - ®smpr_fi_mac® - 12-11-2020
Oh, I didn't understand how that two piece system works. I'll check it out. Thanks!
RE: 20mm bore pulley? - TDKPE - 12-11-2020
(12-11-2020, 11:59 AM)®smpr_fi_mac® Wrote: Oh, I didn't understand how that two piece system works. I'll check it out. Thanks!
The sheave has two threaded holes that when bolts are tightened, the hub is pulled in and compressed on the shaft.
The hub has four holes - two are clearance holes for bolts into the sheave, and the other two are threaded extraction holes for driving the hub back out of the sheave.
It's a high-integrity connection between the shaft/hub/sheave. It also allows selection of an appropriate sheave without regard for the shaft size, as the hub selection takes care of that. As long as the hub and sheave (or sprocket) are the same type, which is "H" in this case.