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Wedge fastener on JA Fay saw shaft, methods for removal?

Wreckitwade

Plastic
Joined
Feb 16, 2023
I'm working on an 1800's JA Fay band saw, and trying to remove the original wooden drive wheel as this is being replaced with a coupling for my new motor drivetrain.

The wooden wheel is captive on the drive shaft, and the flange appears to be held in place with this small tapered key. I did some searching on PM as well as the internet at large. Without knowing what it is, I have had no luck finding mention of such a fastener.

What is it, and what is the preferred removal method?

I tried some light hammer taps to remove it, but to no avail.


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If I am understanding the pictures you posted, it looks like the fit of the hub on the shaft has a good bit of clearance. The end of the shaft looks like someone shortened it with a hacksaw, cutting from different angles. Normally a tapered key would have a head on it, referred to as a 'gibbed key'. This head provides a means of using a steel wedge to break the key loose. In the case of the OP's saw, the key has no head and is nearly flush with the hub. My suggestion, assuming there is some space between the other side of the hub and the bandsaw frame or shaft bearing, is to try driving the pulley hub towards the saw. This would be trying to move the hub in the "downhill" on the tapered key.

I had to measure the keyway in a flywheel hub that was missing a tapered key. Taper worked out to 1/4" to the foot, if I remember right. I milled a tapered key and made sure to include the 'gibbed head'. Tapered keys made to standards are square in cross-section, or at least have more depth to them than what is pictured.

The key in the pictures looks like something that was driven in hard & may not even be a tapered key made to standards. Someone in the past may have taken a piece of steel and got a taper on it (bench grinder ? angle grinder ? files ?) and driven it in with heavy hammer blows. They may have been making a wedge to take up the slop in the fit between the hub and the shaft. Unless I am missing something, it does not look like there is a keyway in the shaft. This would be in line with the idea that a steel wedge was driven in rather than a key. A flat steel wedge made out of any handy chunk of steel and ground to whatever angle and edge would enter the gap between the hub and the shaft is what appears to be there. If driven in hard with heavy hammer blows, there is a good chance the wedge plowed up a wad of metal on the shaft and hub, or galled. This is the likely case, and it is not coming out easily or any time soon without a LOT of persuasion.

Getting things apart is a lot more difficult than with a tapered key, since this appears to be something of a flat wedge. Drilling into the end of the key (or wedge) to try to break the bind is not something I'd try right off the bat. The wedge may be fairly long, and tapered or feathered down to a thin leading edge. One thought would be to cut the shaft off flush with the end of the wedge or grind out a 'pocket' in the shaft so the end of the wedge is not in contact with the shaft. Weld on a puller bar to the end of the wedge. A high strength repair electrode like MG 600 will weld to any type steel and has very high strength. Pricey, but worth it. I'd weld on a steel bar of the same cross section as the wedge, with a butt weld run in from the 12:00 position. Attach a heavy slide hammer (slap hammer) to the steel bar welded to the end of the wedge and try jarring the wedge loose. If that does not work, I would get hold of a "Porta Power" (hydraulic jacking system) with a hollow ram. Weld a threaded rod to the end of the steel bar welded to the wedge. Make a setup against the hub so the Porta Power ram can pull the wedge out. Take strain on the Porta Power and give the end of the threaded rod (attached to the wedge with the welded connection) a good hard shot with at least a 3 lb steel hammer. This method can usually free the hinges of Hell, and lets go with a bang like a 10 gauge shotgun. Been there, done it a few times with frozen coupling hubs and the like. Hollow ram porta powers and sledge hammers work wonders when properly applied.

of a l
 








 
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