David DeCristoforo
05-20-2011, 5:13 PM
Every now and then a tool achieves an almost legendary status. Among turners, the Glaser screw chuck is one of those tools. Introduced in the early 1980's the Glaser chuck quickly became the "go to" screw center holding system. The heart of this chuck was the unique thread that would maintain a tenacious grip on a piece of wood, even in end grain. The chuck disappeared for a time and then remerged in an updated form, disappeared again and has now resurfaced once more in an even better form.
I have one of the original chucks and it is in almost constant use. But I am forever swapping pieces on and off of it. So when the new version became available again, I could not resist the temptation to get another one. It's hard to imagine improving on the original chuck but the updated version does just that. The screw itself is still machined steel and still has the same unique thread that raised it above it's competition. The "old" version of the chuck had a steel body whereas the new one is anodized aluminum. That in itself is not an "improvement" and in fact, I prefer the heft of the steel body. What is an improvement is the incorporation of a removable and reversible collar that threads onto the top of the chuck. This collar serves as a backing plate to provide additional support for larger diameter pieces. Here's some comparison shots of both:
195273195270195271
Glaser also is offering a larger backing plate as an accessory. I don't know what the "maximum" size piece this chuck could safely hold is but it is amazing how well it does hold and a small bowl would not be out of the question. As an experiment, I chucked up a 4" piece of "scrap" wood and turned a "bowl" shape out of it. Then I hollowed it out, being none too gentle but the screw held fast even in the end grain. The pic below is "start to finish":
195272
The screw requires only a 1/4" hole, 3/4" deep to hold the stock. You do have to remember that that steel screw is there and not cut too close to it. You also have to leave a bit more material at the bottom if you need to part off the workpiece.
I have one of the original chucks and it is in almost constant use. But I am forever swapping pieces on and off of it. So when the new version became available again, I could not resist the temptation to get another one. It's hard to imagine improving on the original chuck but the updated version does just that. The screw itself is still machined steel and still has the same unique thread that raised it above it's competition. The "old" version of the chuck had a steel body whereas the new one is anodized aluminum. That in itself is not an "improvement" and in fact, I prefer the heft of the steel body. What is an improvement is the incorporation of a removable and reversible collar that threads onto the top of the chuck. This collar serves as a backing plate to provide additional support for larger diameter pieces. Here's some comparison shots of both:
195273195270195271
Glaser also is offering a larger backing plate as an accessory. I don't know what the "maximum" size piece this chuck could safely hold is but it is amazing how well it does hold and a small bowl would not be out of the question. As an experiment, I chucked up a 4" piece of "scrap" wood and turned a "bowl" shape out of it. Then I hollowed it out, being none too gentle but the screw held fast even in the end grain. The pic below is "start to finish":
195272
The screw requires only a 1/4" hole, 3/4" deep to hold the stock. You do have to remember that that steel screw is there and not cut too close to it. You also have to leave a bit more material at the bottom if you need to part off the workpiece.