I have a screw chuck (???) that someone gave me. It's basically a No. 2 Morse taper with a disc on it and a wood screw sticking out. There is a set screw in the edge of the disc. I used it to make some drawer pulls, but the screw was a little longer than I wanted. I tried loosening the screw and turning the wood screw, but the wood screw was jammed and would not turn. I think it loosened a little but that was it. The question is how does that screw work? Is it a machine screw on one end and a wood screw on the other? Is it just a smooth shaft with a wood screw?
I am not sure if the manufacturer used a hanger screw - machine thread one half and lag thread the other, or as you said smooth shaft with lag thread.
Whatever they used, it is likely the set screw on the side was harder than the lag and cut into the shaft causing a proud edge around the set screw head. This is why you can move it a little but it does not want to come out.
You may need to mount the screw part in a vise with a couple of scraps of wood to protect the thread, then gently drift the taper off the screw.
If it works as is and you want to make the screw shorter use a shim block to push the work piece out away from the shoulder thus using less of the screw.
That is what I did. I put a little shim of 1/4" (5MM??) plywood and turned it down to the base diameter of the pulls I am making. Worked well. Kept me away from the chuck and provided a "target" for the base diameter. Turning the pulls only took five minutes or less each.
At this point I was interested in what to do when the screw wears out.
>>>At this point I was interested in what to do when the screw wears out.
Do you mean this "disk" is machined on the shaft with the taper and the set screw holds the screw into the disk?
If it loosened a "little" think I'd try looking in the hole with a lighted magnifier while turning it and see if there was a clue. But if there is a burr or minor galling it might not matter whether it was threaded or not if you twisted to loosen, assuming you twisted in the right direction! If the burr is small twisting might knock it off. What I do for stubborn things is soak in PB Blaster overnight in case of rust then work back and forth. If that doesn't work, my next attack is with a torch.
Be sure to check for a second set screw...
---
Speaking of screw chucks, hands down best screw chuck I ever used is the Glaser. I like it far better than the wormwood screw often used with normal chucks. I use it on every bowl and platter. I have no idea if it is still available since when I checked a few years ago I couldn't find one.
I looked in the holes for the set screw and drawbar. The drawbar hole is about 3/4" deep and does not go all the way through. No chance of driving the screw t out with a punch. The shaft of the screw appears to have been smooth?not threaded, but the set screw has mangled it a bit. The chuck appears to be made out of a single piece of metal. No chance to unscrew the collar and drive the screw out. When the time comes, I will figure out how to pull it out of there.
That looks exactly like the original Glaser I have except mine is just plain black. I love the screw on these. I had heard these weren't being made/sold any more. I might need to accidentally buy on of these - I'd be in a panic if something happened to this one.
I'm pretty sure what Barry is talking about was sold by Sears (at least the one I have is from Sears). Probably only good for drawer pulls as it is not heavy duty. I have a 3" Screw Center Chuck from Craft Supplies but have never used it. I use the screw and chuck combination of my Nova chucks. I'll bet I start 90% of my pieces with the Nova screw and Nova chuck. This holds so well that I usually have to take the piece out of the chuck and loosen the screw with a pair of water pumps. A lot of folks say Oneway's screw for use in their chuck is the best but do not share that as the first time I tried it in one of my Oneway chucks it snapped in half so I have stuck with my Nova screw.
Mine is tiny compared to the Glacer ones in the picture. The screw in mine I about an 1/8" in diameter and 5/8" long. I drilled a hole just under an 1/8" for it. I am making small drawer pulls.
I like the idea of screwing a piece of wood onto it to get a grip. I gripped it with pliers padded with about five layer of paper to wiggle it. Did not want to smash the threads. I think I will eave it alone until I actually have to remove it. My only fear is I will break it off too close to the base to get a grip on it.
