I found a 1940s craftsman(atlas) drill press a few years ago and rebuilt it. I removed the bearings, pressure washed the castings, etc.
in the process of removing the bearings from the quill I used a brass hammer while holding the parts in my hand as they were a bit tight. Upon reassembly I discovered that the steel is extremely soft and I had mushroomed the end of the taper where the chuck attaches. I put it back together, turned the drill on the highest speed, and used a fine file to remove the mushroomed tip from the taper. The chuck went back on and all was fine for a couple years.
The chuck came off while drilling a few months ago and now it refuses to stay on. The taper on the shaft is visibly not smooth and shiny and needs to be restored. I’ve gotten it as good as I can with fine Emory cloth and a hard backer. I don’t have a lathe to attempt to get a perfect angle on it.
There are two styles of chucks used in these machines, the early style which I have attaches with a taper only. Ie. You can’t put any side load on the chuck or it will come loose. The later style have a threaded collar that holds the chuck onto the taper so you can have side loads on the chuck. See picture below, my chuck is like the far left one. Other picture is actually my chuck.
There are used quill shafts and chucks with the collar attachment on eBay, but I’m fearful of the condition such an old part might be in. (Ie. Warped shaft or abused chuck making it not run true).
What would you do? I’m leaning towards gambling on a used chuck with the flange because if the chuck is trash I can put the insides of my chuck into the new chuck body that has the flange.