Jump to content
I Forge Iron

Fixing A Cracked Bandsaw Wheel


Recommended Posts

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.

IMG_6604.thumb.jpeg.70accfc5f1e39ca7ea6f37700efffa09.jpeg

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.)

IMG_6605.thumb.jpeg.5c16bf08960fa6a05f8a805726b92cae.jpeg

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.

IMG_6606.thumb.jpeg.1475cd39a0ffbe3c673973a26f21642a.jpeg

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?

Link to comment
Share on other sites

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

Link to comment
Share on other sites

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!

Link to comment
Share on other sites

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. 

IMG_6607.thumb.jpeg.00d42c1d62b8b42b23670481d1767487.jpeg

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. 

IMG_6610.thumb.jpeg.488a441517ab5b4f8f74516d1f58570e.jpeg

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. 

IMG_6609.thumb.jpeg.325b2816b8d4a00ac1b04f74906e90b7.jpeg

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). 

Link to comment
Share on other sites

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.

Link to comment
Share on other sites

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

IMG_6612.thumb.jpeg.ef86d680df9c941c923bbe91e155d032.jpeg

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

IMG_6611.thumb.jpeg.482ecf540258359746018b10d6c7a403.jpeg

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.

IMG_6617.thumb.jpeg.08fc1010c93ce6d28a965f76da937222.jpeg

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.

IMG_6621.thumb.jpeg.9a4e693d5a7f811900fe7f3b3bfeae7f.jpeg

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

IMG_6622.thumb.jpeg.ea16fe2e8bcedc834156a9c2448f2d31.jpeg

Everything mounted back up. 

IMG_6623.thumb.jpeg.348533c81e5fe41ad0e0407b2f6d8d33.jpeg

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

IMG_6624.thumb.jpeg.e1f4e3b5e5e45b2353dc3cae8b300d91.jpeg

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. 

 

Link to comment
Share on other sites

  • 3 months later...

Hi,

        Great job there...

Good of you to keep the old machinery going.

This is my 1945 3 PH Wellsaw.

Looks rough, did not paint it, cause I needed it, however...

Did completely rebuild the Gear Box, including replacing a broke Gear.

Wellsaw, STILL completely supports this Saw with any parts you need!

 

 

Wellsaw 1945.jpg

Link to comment
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
×
×
  • Create New...