Hi ya’ll I’m new here. Heard somewhere that some of the post drill gurus live here, so I’m hoping you can help me. I recently came into a Champion Forge post drill, I think it’s a No. 110. It came with a 100 year old Westinghouse ac motor. It didn’t come with a chuck at all, and I’d like to put a Jacobs chuck on it. The real problem is that the spindle ends in a 1/2 “ threaded shaft with a crazy fine thread. It’s not 1/2-20, it might be 28 tpi. I didn’t know there was such a thing. Anyway I don’t know what to do with it, I haven’t seen a Jacobs chuck with more than a 20 tpi thread. I’m going to try attach pics. Any help will be appreciated.