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Fixing A Cracked Bandsaw Wheel

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My old Craftsman horizontal bandsaw stopped working a little while back, and I finally got around to figuring out why. In short, the motor was spinning, but the saw wasn’t.

It seems that the central hub of the drive wheel has cracked where it joins the main disc, throwing the wheel out of alignment so that its gear teeth can’t engage the bevel gear on the main drive shaft.


A little gentle tapping put the hub back in its proper alignment, but I doubt it will function under load. (NB: The paint was pretty flaky, so I scraped it off to get a better view.)


The crack is pretty tight, and I suspect it would respond well to feeding cyanoacrylate glue into it. Still, I’d prefer a more mechanical solution that wouldn’t rely on adhesives. The wheel is some kind of non-ferrous alloy (maybe zinc?), so brazing is out of the question.


I’m thinking of bolting on a round plate with a tapered central hole gripping the hub tightly, or maybe a pair, one on each side. 

Thoughts? Recommendations?

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I think the round plates bolted on either side would work. I would also add some JB Weld to help stabilize the  hub might make a stronger bond. Might try looking at ereplacementparts dot com.they have come through with some obsolete hard to find parts for my old pieces of machinery.


I can't control the wind, all I can do is adjust my sails. ~ Semper Paratus

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9 minutes ago, Irondragon ForgeClay Works said:

ereplacementparts dot com

Their website lists that particular part as “Obsolete — Not Available”. Even if it weren’t, the price is about $390, which is more than I paid for the saw in the first place!

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I have seen some of those that were cast aluminum, if that is what yours is made from it can be welded which would be my first choice for a repair.


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A thought occurs to me: the central hub does not transfer any force to the wheel: it has a bronze bushing that allows it to spin on its mounting pin, and the gear teeth that transfer power from the drive train are all around the wheel’s circumference. 


This means that whatever repair I do does not need to resist rotation in the plane of the wheel, but merely to keep the central hub perpendicular to that plane. 


That being the case, I’m rethinking how best to impart extra rigidity to the hub. One idea that occurs to me is to get a couple of floor flanges from the hardware store, fill them with JB Weld, and put one on either side of the wheel around the central hub. 


Given that this is a fairly light-duty machine that gets occasional use in a part-time/semiprofessional-at-best shop, I think this should be sufficient (and a good bit simpler). 

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There are lots of low temp solders that love zinc / pot metal. Clean the break with an aggressive solvent and perhaps a mild acid / neutralized, to remove any corrosion then flux and solder the break. Check with the local welding supply for the most appropriate solder and PPE requirements. 

This is a pretty straight forward thing. 

Personally I'd go a long LONG way to avoid JB welding machine tool parts, even though JB Weld is much improved since my disappointing experiences using it. Still.

Frosty The Lucky.

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Well, here’s how things progressed. A 1-1/4” floor flange fit nicely over the center hub. 


But was too tall for the center hub on the other side. 


I therefore went with just the one flange. After improvising a gauge to make sure that the wheel was properly aligned (or as close as I was going to get with a die-cast part), I glued the crack with cyanoacrylate. This stabilized it for the next operations.


The wheel was drilled and tapped to take some 1/4 x 20 screws I had knocking around. Then I glued down the flange, filled the space between it and the center hub, and extended it upwards a bit, all with JB Weld.


Some nylon lock nuts on the back, and we’re good to go. 


Everything mounted back up. 


And successfully sliced though some 7/8” x 1-1/4” O-1. 


All in all, I’m quite happy with how this turned out. I might still add another flange to the back (with the threaded section trimmed down a bit), but that can wait. 


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Except it’s the patient who’s doing the cutting!

 Seriously, the saw is cutting better than it has in a long time. I’m quite happy. 

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