Pin Chuck

Hi Alan

The dimensions are OK and you can use a pin chuck as long as you keep that tailstock in your way to keep the turning on that pin chuck. But why use a pin chuck ?? I'd rather use a woodworm screw, it gives you more flexibility in working without the tailstock in your way, is also very easy to install and use, have a look at one of my albums and see for your self.

Hi Alan,

Like Leo, I must admit that I prefer the screw chuck ... I have actually built a pin chuck with # your dimensions and tried to use it several times with "big logs" (at least big for my lathe : # 30 cm diam) :

-> after several times, the pin rolled and the log loosened (maybe the wood - cherry, cypress - was too soft or not dry enough for this kind of chuck). I even tried to accentuate the slot and change accordingly the pin size ... but, even if that became better, it "couldn't get now satisfaction" and the log began to chatter once again ...

Maybe some other users can explain why the pin chuck is able to work well ?

Have nice shavings :-)

JYS31

Mine's an inch in diameter, and the current one's 1.5 long. Older one was a bit longer. but it was a bi-directional type with smaller roll pin - more of a metalworker's design. The current

Hey guys, 'Scuse my ignorance. I'm not following this pin chuck thing. George, how does this thing grab the piece? Saw your picture and it just looks like a tiny pin penetrating the bottom for grip. That's not impressive.

I thought this "pin chuck" would be the equivalent of a a 2x4 with nails on the ends to grab a log to begin turning a foot or chuck grabbing surface. Then proceeding as normal. In a case where the screw chuck would penetrate too deeply. I guess I'm just lost on this one. Maybe need another cup of coffee to wake up:).

TomNie

The pin tries to roll up the ramp against the rotation, and succeeds in wedging the entire piece into the cylinder. In my experience, as I said, the only thing that defeats it is startup inertia on really soft wet woods. Can't say the new one has ever done it, though the old one would at times.

I was feeding the stove this morning and saw a lump I wanted to turn. Since I use the pin chuck by habit, I had it on the lathe before I realized that it would have been impossible with a screw, as would a turning I did a few days ago. I was attempting to get some swirl by centering up a knot to be turned out later.

Hi Wally

Wally how is it that you can drill a hole and put your blank on a pin, but you would not be able to screw it on that pin if it had thread on it, inquering minds like to know, also how is a unbalanced wet half-log or burl safely held on a 1" or 1.5" long smooth pin without a tailstock to keep it from sliding off, as your tool hits a harder spot or wing, the wood will be jerked back and then surge forward, back and fort, back and forth. There is a reason why 4 Jaw chucks and wood screws are popular, and it's not for their cost. Also the brought up nonsense of the woodworm screw rusting, it is BS, if it would rust under normal use, which it does NOT, it would not rust any more that a pin chuck, if this rust is a problem for some one, they are made in stainless steel version also. I use a Oneway woodworm in all kinds of wood, like red and white oak, black cherry, etc. It was for this rust claim that I put up the photo album to show the non existing rust. Also the album with the woodworm screw, it safely holds a large half-log blank without the need of tailstock support. However there are some that want to keep spreading misleading information.

Believe me Leo, it does work! I've used the pin chuck many times.

The pin chuck is usually 1 inch in dia. and about 3 to 4 inches long. I drill the hole in wood around 2 inches deep. The pin chuck should bottom out in the hole, which makes it secure and quite solid. With the tool rest perhaps 1/2 inch from the wood, the blank can't possible back off the pin chuck. However, the tailstock does make it more secure. Using a screw center (which I use a lot in other ways) on an uneven or round surface doesn't work well, especiall if the wood or even bark isn't solid

I don't understand your comments in the form of a reply on the wormwood screw and using a 4-jaw chuck. None of that was mentioned in my post.

Leo, I started turning 70 years ago and I've taught woodturning to many, many students and I don't spread misleading information.

Wally Dickerman

Hi Wally

You are saying that your toolrest is preventing the wood from coming of the chuck ?? I would not want to stand there if the wood grabs onto the toolrest, something is going to move real quickly, also if the wood is not solid the pin chuck would not hold either in my estimation, and bark should be removed in any case. Didn't you say "a tool that preceded the 4 -jaw scroll chuck that's so popular today" ??. The so called rust problem is in this thread and brought up before, not by you.

My first chuck as well. "Masterchuck" it was called. Henry Taylor was the manufacturer. Fussy sonofagun, with that secondary locking ring for gripping a tenon. I think that's what turned me off of tenons, fighting that beggar.

You have a 1" thick by 1.5 long solid metal (tenon) cylinder wedged into the (mortise) recess. If you really think that a 3/8 x 1" screw which has already begun to crush and cut fibers as it's inserted can come close in security against side loading, you are sadly mistaken. With all the surface in contact with the wood, it's often necessary to tap around the edge of the piece with a mallet to get it off, even when the pin has already been disengaged.

For those who are curious as to how well it works,

Leo, it seems to me that you are arguing about something that you obviously know nothing about. The pin chuck has been around and successfully used for many, many years. They are even sold now in 3/8 inch size for turning bottle stoppers. I've been using mine since the early 80's The pin chuck is a much solider, safer tool to use on a soft, wet piece of wood than any grub screw.

Axminster manufactures a pin chuck designed to be used in their scroll chuck.

I seldom use a tailstock when using a pin chuck. I've done it dozens of times and have never had a problem.

I don't know how long you've been turning, but the 4-jaw scoll chuck came on the market somewhere around 1990. I have one of the early Nova chucks. The "6 in One" tool was sold in the 70's and 80's. It is actually a collet chuck with attachments including a pin chuck. I still have mine but it gathers dust.

Wally Dickerman

Hi Wally

Yes Pole lathes, hook tools, spike chucks and pin chucks have been used for a long time, Some are still used, maybe all, that still does not tell me that a woodworm can not be use where a pin chuck is used, and you are of course entitled to your opinion that a pin chuck is a much safer chuck in a soft wet piece of wood, I just don't deal your opinion. It has it's place, like in bottle stop turning or butt vases, or in conjunction with a tailstock for larger pieces.

Have fun and take care Leo Van Der Loo

I appreciate everyone's input and have a further question. In the photo George posted earlier (closeup of the pin chuck) the recess appears to be hollowed, ie not simply a milled flat section as you may find on a shaft to accept a grub screw from whatever slides onto the shaft.

I was considering having the recess flat bottomed for ease of manufacture, though I expect avoiding the pin rolling off may present a challenge. Any reason, other than ease of assembly that supports a need for a hollowed recess?

Thanks, Alan

Leo.. If I can't use the chuck screw, and can drill a 1 or 1 1/2" hole, I'd just as soon use that hole as a recess for the spigot jaws... YMWV

Mac

Leo and Mac--One thing to remember in deciding which type of support to use is: the two methods hold the wood in somewhat different ways. A screw chuck draws the wood toward the spindle, until it presses firmly against the jaws. This holds the wood squareto the lathe axis. A pin chuck generally goes deeper than a screw chuck, and has a larger diameter, so it provides more alignment merely by the fit of the pin to the hole.

The wood may realign itself as it draws up on a screw chuck and meets the jaws, so the axis is actually determined by the outside shape of the piece. On a pin chuck, the alignment is pretty much determined by the hole axis.

Second, it you want to do any cutting on the side facing the headstock, the screw chuck has better control of the wood, not allowing it to drift off its support (assuming the tailstock has been removed.)

Leo,

You are correct they do hold the timber in different ways and that is exactly why I want a pin chuck as well. I appreciate that there are merits to both systems and didn't intend to start a debate on which IS best. Like many things, usually there are situations that lend themselves to each...or both. My interest in a pin chuck is for something like half sawn logs. I don't want to have to square up a face so the screw can pull the wood hard against a support, like the chuck jaws or faceplate.

From the way you describe the pin chuck, it seems you feel the timber can drift off. Remember, it is more than just a large cylinder of metal poking into a hole; the actual pin is a small but vital component to it. The pin rolls to the side to increase grip on the wood but is held within a recess so it cannot just slide off the end of the spigot/tenon...whatever you want to describe the main part of the chuck as. See George's closeup photo. That said, every system will have limitations as to what it is wise to try; screws included.

Again, appreciate the comments.

Safe Turning, Alan

Yep, it's much more "proof" against rollout than a simple flat. Used the simple one until last year, and this one, which appears to have been milled in at an oblique angle to cradle the pin. Allows a larger diameter pin, though I'm not sure that's important. Disadvantage - not bi-directional. With no reversing switch or desire to install one, not a problem to me.

Of course, if you want to cut opposite the tail, you can use the tail to make it proof against slipping, so what's yer point? I use it when I have an out-of parallel situation between large and small surface, reducing the large surface for better balance.

There are a lot of people who don't understand the concept of adding support at right angles to the axis of rotation to make a hold more secure against racking. Which is why, of course, we put a bearing shoulder or a smooth bottom to snug against when using a tenon or a mortise with our chuck, or shoulder a tenon in flat work.

Those who like the screw can make things better by cutting overlapping holes using their drill press, depth stop and a Forstner bit to create a flat for the boss of the screw or the jaws of their chuck to bear against prior to boring the center hole. Depends on the design of the screw and the size of the piece which you choose.

Mac, you can use jaws in some cases, as you know. I use my pin jaws on small work all the time, but you cannot use them or a screw chuck effectively on very soft or spalted wood, or in cases where you're working with a knot or other bark "feature" in the center. The pin chuck is not as particular, because it brings a lot of surface into contact with the wood. Spreading the inevitable force over a broader contact area gives obvious advantage when the area itself is soft or frangible. There should be few others who would disagree that broader contact area is a benefit. I have to assume those who don't have never added a washer to a bolt.