Old band saw help

[Amrjon]

Hi, I have this nice little old Aussie made bandsaw. I'm going to clean it up, but I have a problem with the bottom wheel freewheeling on the drive shaft.

There is a key on the driven side where the pulley mounts, but on this side there is no key or other method I can see to make the secure the wheel to the shaft without slipping.

There's a thread and nut on one side and a bush on the other.

What am I missing?

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[OccupantRJ]

If you tighten the nut up, does it stop the shaft from turning? Very unusual, but if there is not a key or setscrew in the assembly, it looks like a compression attachment which would be very unusual and poor engineering. There would have to be a shoulder at the bushing area of the shaft for the hub of the wheel to tighten against if this is the case.

If this is really the case I would assemble everything, check for freedom of rotation, then drill all the way through the hub and shaft for about a 3/16" roll pin to insure positive drive and to allow easy disassembly later if needed. The hole can be at a slight angle if needed to allow easier drilling. If so, I would mark the shaft and wheel as to how they line up with each other.

I looked again at the pics and the shaft does appear to have a step or shoulder on it, so it may very well be a compression type attachment.

 

[Amrjon]

You might have solved it in one. I just took a look and there is a shoulder on the shaft but it's not protruding past the bush so I didn't see it. If I back off the pulley on the other side that should let the shoulder should clear the bush.
I'll give it a try tomorrow and let you know.
Thanks.


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[Amrjon]

Sorted. Thanks occupant.
I knew I was missing something, just didn't know what it was.
I just had to let the shaft move through a fraction and the wheel hub now clamps up to the shoulder.
Still not a great design as you point out, but hopefully good enough for job.
Cheers.



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[Doug Arthurs]

I would consider milling a keyway in the shaft and hub for a more positve drill.

 

[OccupantRJ]

A cheap home brew method of making a key on a shaft/hub assembly where the shaft is flush with the hub is to drill and tap right on the parting line between the two. A setscrew can then be used to act both as a key and as a axial locator.

 

[Amrjon]

Thanks, I'll look into doing something if there is any sign of slipping.


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[crguy]

A cheap home brew method of making a key on a shaft/hub assembly where the shaft is flush with the hub is to drill and tap right on the parting line between the two. A setscrew can then be used to act both as a key and as a axial locator.

A good idea, and something that can be accomplished with basic tools.

 

[OccupantRJ]

I came up with this method to repair motorcycle shifter shafts after the owners would let the pinch bolt get loose (usually kids) and the shift lever would gnaw the splines off the shaft. Most people would rather do that than tear down to replace things, as it cures the problem without being invasive. If the occasion arose to replace the shaft, it was still easily done by removing the setscrew.