Don Kinzer
Cast Iron
- Joined
- Mar 18, 2002
- Location
- Portland, OR USA
I posted some time back asking how to remove the X-axis handwheel on my K&T 2CHL. I was assured that if I just removed the pins it should just slip off. Well, removing the pins wasn't so simple. One had enough of a hole in the end that I forced a sheet metal screw into it and pulled it out with pliers. The other one, I had to drill a hole in to do the same - fortunately, it didn't spin during drilling (which should have been a hint of things yet to be discovered).
To my dismay, the handwheel refused to budge after removing the pins. I finally rigged up a 2-jaw puller and, using a spacer over the clutch release rod, I was able to remove the handwheel. However, it came off leaving the handwheel bushing on the shaft.
I tried a couple different setups trying to pull the bushing off the table screw using pins projecting into the bushing holes. Even though I exerted substantial force the bushing wouldn't budge.
Finally, I decided to surgically remove the bushing by drilling a series of holes along each side and then using a very thin abrasive wheel to split the bushing. After finally getting it off, the reason for the intransigence became clear: over time the pins had rolled up a ridge on the inboard side of the retaining slot which projected into the I.D. of the bushing. The photos below illustrate the problem. The nominal diameter of the table screw where the bushing sits is 0.875" and the diameter of the ridge measured about 0.950".
In the photo of the bushing you can see the groove carved into the bushing by the ridge. You can also see the deformation of the hole on the left side caused by the pins when I was trying to pull the bushing off.
My plan is to remove the ridge using a grinder to remove most of it and then using a file and emery cloth to remove the rest. Then, I'll make a new bushing and new pins and I'll be good to go.
To my dismay, the handwheel refused to budge after removing the pins. I finally rigged up a 2-jaw puller and, using a spacer over the clutch release rod, I was able to remove the handwheel. However, it came off leaving the handwheel bushing on the shaft.
I tried a couple different setups trying to pull the bushing off the table screw using pins projecting into the bushing holes. Even though I exerted substantial force the bushing wouldn't budge.
Finally, I decided to surgically remove the bushing by drilling a series of holes along each side and then using a very thin abrasive wheel to split the bushing. After finally getting it off, the reason for the intransigence became clear: over time the pins had rolled up a ridge on the inboard side of the retaining slot which projected into the I.D. of the bushing. The photos below illustrate the problem. The nominal diameter of the table screw where the bushing sits is 0.875" and the diameter of the ridge measured about 0.950".
In the photo of the bushing you can see the groove carved into the bushing by the ridge. You can also see the deformation of the hole on the left side caused by the pins when I was trying to pull the bushing off.
My plan is to remove the ridge using a grinder to remove most of it and then using a file and emery cloth to remove the rest. Then, I'll make a new bushing and new pins and I'll be good to go.
