Jam chucks are quick and easy to make and often better than mechanical chucks in many re-chucking situations. Here you see how to fit a box lid and small bowl over a jam chuck, and then fixing an enclosed bowl into a jam chuck.
As part of a project to make a bunch of turned storage jar lids for friends and family, I learned to use jam chucks routinely. Very easy and very useful. Thanks for the video. 👍
Very informative and a big help to me, Richard. I've always tried to avoid using jam chucks, but this explanation has shown that they're not as mysterious or daunting as I've found them to be.
Before the modern self-centring chucks came along I used a cup chuck, essentially a jam chuck, in production to make thousands of scoops. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-D3znG7-ksIw.html Once you get the hang of jam chucks you'll find them enormously useful.
Great video. A couple points: creation of a burnishing line also burnished your work, which isn't desirable. I check fit with the lathe off. You can drill a hole through the chuck, and use a dowel as a knock-out rod. An ill-fitting jam chuck is a great way to split your work. I recently added an internal support dowel to a jam chuck (3/4" dowel friction-fit and adjustable with a hammer) to provide bottom support when removing a tenon with tailstock support. If using the tailstock, as the bottom thins, the tailstock pressure may become enough to split the bottom (learned the hard way).
If you go gently, burnishing the work shouldn't be too much of a problem, and I've rarely found it so. Go too hard and you have a none-too-decorative charred ring or burn mark. I avoid using knock out bars or sticks on finished work, mostly because of the risk of going through the bottom of something.
Basically the same but with tailcentre support. There are three variations in the recent crossgrain cylinders video ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-IX8_MD1O6js.html. Or at 21:09 in the pencil pot video ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Q6pq2_cQAuE.html you see an endgrtain version.
Well, after a month of home renovations I finally have time to watch some videos again! Very informative as always, many thanks! Are there types of wood you would advise not to use as jam chucks? Or certain types are fine, just not on some types? Thanks once more for putting your knowledge and skill and experience out there.
I prefer using softer woods so there's a bit of give in the surface, however slight. And if the wood's been felled a few months, so not dry but not wringing wet and spraying sap, the damp enhances the grip of the chuck.
Occasionally I have a knock-out hole,but not always in the centre. On larger chucks for bowls a slot near the rim does less damage to the bowl when leverage is required.
Hi is there a way of making a wooden jam chuck for a pool cue i need to hold end of two piece to turn down for a new brass ferrel at tip end. I have made a steader from 3 bearing casters with rubber wheels any tips
I'd grip the very end of the ferrule end in pin jaws, refit the ferrule and be resigned to losing 15mm off the tip of the cue. And support the other end of the cue with the tailcentre. If it's a brass cylinder it'll fit over the conical centre. You shouldn't need a steady working close to the chuck.
