An elegantly designed beautifully manufactured tool, made for use. Not at all its equal for serious bowl turners, but 'faceplate chucks' can be useful. Nothing but short bolts bolted thru a faceplate.
Most turners just grind points on the tips of the bolts, but I find that grinding a tiny single bevel edge gives a better grip. I have a dedicated heavy 2 in. drive plate, but temporarily adding 2 or more bolts to an ordinary faceplate doesn't destroy its original use. Also the bolts need not be on the same radius so they can grip & drive on different sections of the blank.
Sears used to sell a heavy drive plate with loosely insertable single bevel pins that kept falling out til I lost them. :)
Turn to Safety, Arch Fortiter
I don't know about you, but I would be extremely reluctant to put a 200 pound blank on a chuck like that. A between centers spur drive is far less likely to fail and the two point support (drive and tail) really helps keep the wood from flying around. In fact, I can't see where I would use a pin chuck - by the time I'm ready for a chuck, I can just use a standard chuck with jaws - what am I missing here?
Not answering for George, but I use a nova chuck with pin jaws. These are 1 inch long and 1 inch diameter closed. Instead of using a faceplate for initial roughing the outside, I drill a 1 1/8 hole and slip it on those jaws, using tailstock support. Works real fast and when it is balanced and shaped, just back away the tailstock and turn the dovetail recess. I imagine his 1 inch pin chuck would work just as well.
I do have a real pin chuck, but it is only 3/8 inch and I use it for bottle stoppers and such.
Pretty much everything, it would appear. Imagine your four frail jaws which penetate perhaps a quarter inch replaced by a robust 2" long 1" thick steel extension of your spindle and you'll get some idea of the capabilities.
Anyone who doesn't use a tailstock until working the place where it beds, regardless the method is not being as safe as they can be, so once again, the pin chuck and tailstock are certainly MUCH more resistant to lateral stress than something which has to seat itself into wood which is perhaps damp, at shallow depth, and perhaps even along the grain when you whack the toolrest with that knot you didn't see and dismount the whole. Matter of fact, the spurs along the grain are essentially worthless, which is why the two-fanged varieties which can go across the grain, taking the stress on endgrain are so commonly used.
So bore a 1" hole into your blank, regardless the surface, tap it up on the chuck and engage the tailstock. Never a chance of a dismount.
Hi George
You must have one of those dinky jaws then, Have a look at the Oneway spigot jaws, they go at least one inch deep in there, and hold al the way around, not like that little piece of nail in your pinchuck, that's chewing the wood on one side, and might have no hold at all in that soft wet wood, you where talking about.
Just to make it easy, here's a l> Pretty much everything, it would appear. Imagine your four frail jaws which
My major problem with using a pin chuck is the same as for using a faceplate -- once you have drilled the hole you have decided where the center of the piece is going to be and also the orientation. As things develop, defects are exposed, or pattern manifests itself, you are a helpless bystander -- it is very difficult to change anything.
When starting between centers it is easy to reorient the wood when you find you have not made the best choice. You can marvel at the beautiful orientation in the pieces done by people like John Jordan but you cannot duplicate it. He doesn't have x-ray vision, he starts between centers and adjusts as he goes.
Bill
George wrote:
Well, of course the turner's eye can fail him occasionally, even if reading the wood is a part of the art of turning. Sometimes you cut too far and delve into a bark pocket or just have plain bad luck.
Fortunately there's an easy answer. Plug the old hole, drill a new one in the desired orientation and begin turning as you did before. The hole is, after all, something that will disappear when you're done hollowing, so neatness doesn't count.
Those who are not institututionally biased will, of course recognize that the roll pin is just that, a pin designed to resist the roll of the piece. With soft wet woods I hedge my bets by starting the piece in motion to reduce the starting shock. You know, the same starting shock that chews the spurs out of the same soft wet wood, or chews the tenon up even worse by gnawing them with toothed pieces of metal. If you have soft start, probably don't need to bother, but it's a easy thing to do anyway. I can have the piece turned, the mortise cut, embellished and sanded, even have the piece hollowed around the pin chuck pillar and decide to go back and reshape the bottom. I just mount the pin chuck in the same _undamaged_ and perfectly centered hole and begin turning the outside again.
Why destroy your centering, mounting and recentering capability when you don't need to? Or give up a center mark if you're turning between 'em?
"George" wrote: (clip) Fortunately there's an easy answer. Plug the old hole, drill a new one in the desired orientation and begin turning as you did before. (clip) ^^^^^^^^^^^^^^^^^^^ If you want to make a small adjustment on a spur center, it's just a matter of backing off tailstock pressure and making an incremental adjustment. You have the opportunity to do this more than once, even, without much difficulty. Removing the wood from the lathe, turning a plug and redrilling is a lot more work, but more important: how do you establish the location for the new hole?
Also, if it is a lot of work to make the change, it is tempting to avoid doing it, especially making small incremental changes.
It is a nuisance trying to make very small moved on a spur drive, because it wants to keep going back into the same notches. I'd like to know how others deal with this.
Since we're talking about large pieces, I would like to suggest a method I find useful--place an automotive scissor jack under the wood to hold the weight before releasing the tailstock pressure. Then use the jack to raise the wood to the new center line. Lot easier than trying to support a heavy piece with one hand while making all the other moves.
Well, haven't done it a lot myself. Having taken wood apart by the cord over the years, I find I'm a pretty good judge of what's there. When I did, I drew a line where I wanted the new axis, shimmed it under the drillpress and bored the hole.
Haven't caught one in the chops, ever, since even when I used the spur center and its pathetic grip, I counterbored about a half inch to make sure it could slip, but not flop. Not even a face mask is gonna save you from "the big one."
"George" wrote: (clip) when I used the spur center and its pathetic grip, I counterbored about a half inch to make sure it could slip, but not flop. (clip) ^^^^^^^^^^^^^^ Actually, that is a very good idea. In a way, you were evolving the spur center into a pin chuck.
Bill R., how about a new procuct: a pin chuck with a spur drive on the end, so the floating pin is eliminated?
"Leo Lichtman" wrote
Leo Try putting a shot of hot glue in the notches from the sour center before inserting to the new place. I am not sure if the heat from the glue swells the fibers or the glue itself is strong enough for the new hold but it seems to work the few times I have tried it.
God bless and safe turning Darrell Feltmate Truro, NS Canada
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