screw chuck vs. face plate

[hydrojohn]

Still a novice at turning. I am looking at trying my hand a turning a large bowl from green wood (heavy) Diameter will be 12 inches and 4 inches thick. Is using a screw chuck an option or should I only be thinking face plate?

 

[dkulze]

I'm gonna chime in here as the proponent of choice number 3, John.

I actually do not use a faceplate or a screw chuck. Have actually only used a faceplate once and, in retrospect, will probably not use one again except under quite remarkable circumstances. I've found that mounting between centers, roughing, and cutting a tenon for my chuck is the way I vastly prefer to start. To me, it's been a safe and stable way to start.

Once I've roughed and cut the tenon (and often just cut the tenon, with minimum to no roughing), I mount the piece in the chuck and bring up the tailstock for support. From there, I can remove most of the material that's coming off then remove the tailstock and finish.

Actually, I do use my faceplate quite a bit. I have a piece of oak board mounted on it and an adhesive sanding disk on this, and use it as a circular sander.

My woodworm, which I also use quite often, is mounted in a block of padauk and is used to hold drilled out bottle stopper blanks for turning.

So that's my alternate way to go. Please don't take it as meaning that faceplates and screw chucks don't work well and aren't valuable tools. Just know that there are many ways to mount up big wood.

Good luck,
dietrich

 

[john lucas]

A screw chuck should work fine on a bowl of that size. Make your tenon so that it has a square shoulder. The wood should not bottom out on the face of the chuck but should sit firmly on the face of the top of the jaws. This shoulder as well as the grip from the jaws are what keep the bowl solid. If you don't have a shoulder that sits on the top of the jaws the vibrations from cutting can cause the wood to rock in the jaws and eventually come out.

 

[Griesbach]

I believe I'd be thinking of using a face plate attached to what will be the opening part of the bowl and forming the outside of the bowl, leaving a tenon for a scroll chuck at the base of the bowl. At this point you will have a reasonably balanced piece for the chuck to hold while you turn the inside. As this is a green piece you will have quite a bit of weight so a face plate is in order. Also remember that a screw chuck will not hold in end grain. Be sure to leave the thickness at least 10% of the diameter of the bowl so you will have enough material available for truing up after the wood dries and warps.

 

[n7bsn]

I believe I'd be thinking of using a face plate attached to what will be the opening part of the bowl and forming the outside of the bowl, leaving a tenon for a scroll chuck at the base of the bowl. At this point you will have a reasonably balanced piece for the chuck to hold while you turn the inside. .....

This is close to how I turn a bowl, except I bring the tail-stock up and support that way. Until I actually need to cut the tenon.

 

[Kefferpl]

If you start a bowl between centers you can set the grain pattern you want. This will give you the ability to balance the look of the bowl the way you want it. Then create a flat for the face plate - or start a tenon for a chuck. If you start with the blank on face plate or screw chuck - the center is what you picked while the blank is rough. You can loose more bowl diameter trying to get a grain match or look you want on the inside.

 

[John Nicholas]

My First Bowl

I turned my first bowl with my Turning Club Mentor, Ray. He had two peices of Honey Locust and 2 lathes. So we spent a Saturday turning.

I learned that you spend your time up front probably an hour before the blank went on the lathe. 1. Pick out your orientation, which side will be the top. 2. Pick the center that will give you maximium size. Circle templates help. Use a crayon or china marker or something and mark out your diameter. 3. Use a square and find the center on the foot side of the vase. Mark that also and the diameter with your crayon/china marker.

Since the blanks were flat, with the pith removed, we went with a worm screw mount in the chuck. Reasoning was that you had better support with the chuck jaws.

Then rough the circumfrence and shape the outside of the bowl and the spigot for the chuck.

My bowl came out at 5 inches, 1/4 less than planned. 3 inches high and a consistent 1/4 inch thickness.

I've watched Ray at club demos since and he uses other mountings depending on the challenge of the specific piece. BTW: Ray got a nice bowl too. Slightly larger, slightly thinner.

John

 

[Bill Grumbine]

Well, I like to go real fast, shavings flying, tool tip hot, blah blah blah. But even if I didn't, I still prefer a faceplate. Even a small catch on a blank held by a screw can make everything just a little bit smaller since it will probably need to be retrued. Grain selection for symmetry is not all that hard to accomplish if you pay attention to the log as you cut it.

Now for natural edged bowls, and most burls, I will start between centers. I have used my screw chuck about three times in the past five years, although I do use smaller screws for knobs and things like that.

Paul, we are practically neighbors! But you might already know that if you are who I think you are.

Bill

 

[Kefferpl]

Bill,
I've had the great good forture to meet you, However since I did. I haven't recive my journal on time. Just got mine last friday- had to call for replacement.

 

[Norm Smith]

I think that as time goes on you will find that there is a place in turning for a face plate, screw, or between centers. It will depend on the size and shape of the piece of wood and what you want to do with it. Keep an open mind and expierememt.
If you havent seen Bills DVD, I suggest that you get one. It is very informative.
Norm

 

[MichaelMouse]

Still a novice at turning. I am looking at trying my hand a turning a large bowl from green wood (heavy) Diameter will be 12 inches and 4 inches thick. Is using a screw chuck an option or should I only be thinking face plate?

A screw chuck is a faceplate with one screw. As such, it's a bit more vulnerable to tear-out at the threads, wobble when the jaws don't mate firmly, and unwinding if you don't have your tailstock in place. I take it as something for the up to 6" size.

In either case - plate or screw chuck, help yourself by fixing the piece in the proper orientation, opening side up, and use your drillpress, the depth stop, and a Forstner bit to level the section where the jaws will meet the surface, or the faceplate be bedded. Lot of safety and security in that simple procedure.

I've used a pin chuck for the last fifteen-twenty years, because one came along with my first "Masterchuck." It's incredibly safe and easy to use, as all you need is an appropriate depth 1" hole. It's also nice because you can cut a recess or a tenon on the other end, as you please. The rough will hang in position for either to be prepared.

What I would avoid is starting with the drive center, especially with wet wood. If your tailstock slips, you didn't catch the fact that the wood's a bit punky on the outside, or maybe you overcommit and get a catch, you can be chewing the blank. It is safer if you bore a 1/2 - 3/4 deep hole the size of your center, but if you're going to do that, you'd be halfway to a pin chuck!

Someone's already brought up the classic objection of not being able to move the bottom to change grain presentation. Might be a factor in some things, but in a bowl you already have a good idea what the piece can be - you have made it near circular so as not to beat your lathe to death - so any movement from there just gets you an out-of-balance smaller capacity piece. If you use a pin chuck you just glue in a 1" dowel, reorient, bore, and go. Think I've done it two or three times overall.

 

[underdog]

What's a "Pin Chuck"?

Is it the same thing as the "worm screw" that came with my Nova Midi Precision chuck?

 

[Bill Grumbine]

Bill,
I've had the great good forture to meet you, However since I did. I haven't recive my journal on time.

Guilt by association Paul! You are doomed!

 

[hockenbery]

1. I start all my students with screw in the scroll chuck with a disc 8" diameter 2-3 inches thick. This way they learn to use the gouge more efficiently and are forced to make a shallow open bowl which is the easies for newbies to turn.

2. I then tell them this may be the last time they ever use the screw and teach them roughing between centers. This is a quick mount and allows the freedom to quickly reposition the piece to align the grain or position a wood feature in or out of the rim.

3. That said, many production bowl turners use the screw chuck. The work with large symetical logs and the grain from the chainsaw cut is usually acceptable.

4. In my own work I almost always start between centers. A vote for option 3.

I'm gonna chime in here as the proponent of choice number 3, John.

I actually do not use a faceplate or a screw chuck. Have actually only used a faceplate once and, in retrospect, will probably not use one again except under quite remarkable circumstances. I've found that mounting between centers, roughing, and cutting a tenon for my chuck is the way I vastly prefer to start. To me, it's been a safe and stable way to start.

dietrich

 

[hockenbery]

What's a "Pin Chuck"?

Is it the same thing as the "worm screw" that came with my Nova Midi Precision chuck?

A pin chuck is a round bar with a flat on one side. A thin rod is put on the flat and inserted in a hole matching the pin diameter. twisting in either direction locks the piece on the pin when the little rod rolls along the flat and binds.

these have two down sides the first is keeping trackof the little rod and if you leave green wood on one too long the only way to get the pin out is to chisel it out. To some extent leaving green wood on a srew too long can require chisel removal too however the screw threads will usually back out with enough muscle.

happy Turning,
Al

 

[MichaelMouse]

A pin chuck is a round bar with a flat on one side. A thin rod is put on the flat and inserted in a hole matching the pin diameter. twisting in either direction locks the piece on the pin when the little rod rolls along the flat and binds.

Not all pin chucks are bi-directional. We can say that here, right? The one I got from BestWoodTools is uni-directional, and much more suitable for wood work than the other, common for metal. I have never experienced over-roll with this one, something that could happen on the old chuck with soft wet wood like aspen, and sufficient startup inertia. It's not in their slowly updated website or catalog, so you'll have to call and order one if you want it. ~$65 as I recall.

As to shortcomings, the answer to the first is to have enough roll pins on hand so that you never have to stop work to search. I magnetized mine, so it stays in pretty nicely. If it drops in the shavings bag, I "pan" for it by shaking, and find it on the bottom. Corrosion comes from carelessness, and can happen with any hold method you use. Don't leave wet wood on your chuck, pin or otherwise. You'll want a mallet dismounting, because the cylinder creates some vacuum.