Hello,
I have a four jaw skinner chuck #4006-56 that came with the lathe I purchased. (South Bend 9a.) The chuck wasn't installed when I bought it. My issue is that the chuck won't thread onto the spindle. I've measured the threads and it appears to be 1 1/2 8 like the spindle, but for some reason will only thread on for about 3/4 of a turn. The threads are clean and clear of any chips or burs. I'm trying to figure out why it won't fit. I've removed the back plate from the chuck and have tried screwing it onto the spindle from both sides. Same issue. 3/4 turn and stops. The threads on the chuck have a somewhat flat spot on the crest. Could the chuck threads possibly be acme? Did any of these chucks come that way? I'm fairly confident they are not metric. Couldn't get my metric thread gauges to match up. I'm attaching a few pictures of the chuck. Any thoughts on what I'm dealing with here?
I have a four jaw skinner chuck #4006-56 that came with the lathe I purchased. (South Bend 9a.) The chuck wasn't installed when I bought it. My issue is that the chuck won't thread onto the spindle. I've measured the threads and it appears to be 1 1/2 8 like the spindle, but for some reason will only thread on for about 3/4 of a turn. The threads are clean and clear of any chips or burs. I'm trying to figure out why it won't fit. I've removed the back plate from the chuck and have tried screwing it onto the spindle from both sides. Same issue. 3/4 turn and stops. The threads on the chuck have a somewhat flat spot on the crest. Could the chuck threads possibly be acme? Did any of these chucks come that way? I'm fairly confident they are not metric. Couldn't get my metric thread gauges to match up. I'm attaching a few pictures of the chuck. Any thoughts on what I'm dealing with here?