Chucks: To Use or Not

[Ned Ladner]

Just got through watching a YouTube video entitled " The Limitations of Chucks" by Lyle Jamieson. He said that the tenon for a chuck should be at least 40% of the object diameter (4" tenon for 10" bowl) so it seems that chucks are only feasible for fairly small objects. He also stated that chucks should never be used for hollow forms.

In order of holding power he rated face plate with many screws #1, glue block a close #2 and chucks a very, very distant #3..... said he hasn't used chucks in 20 years due to this.

Thoughts and comments?

[Thom Sturgill]

I like a worm screw for outside work though I often start between centers instead. 5" jaws (expansion) are readily available for the SN2 and up to 7" for the Vicmark.

[Mike Cruz]

Not so sure you NEED 40%. I just recently roughed out a bunch of bowls ranging from 15-18" using a faceplate to start. Even did a 19" platter. I turned a tenon on the bottom of each blank and shaped the outside. Put it/them in a chuck and either cored or hollowed out the inside of the bowl. Largest tenon I made was about 4 1/2". None broke. None gave way. I was at what, 25-33% of the diameter?

[Scott Conners]

Many of the things I do, I couldn't do without a chuck. It's not the only solution, but definitely an important tool in my arsenal. Using a glue block or faceplate slows the process way down for some turnings. Also, a small tenon can rk fine in good wood if you use the tailstock as much as possible. I also have a low power lathe, so I'm not trying to take off 3/4" on a single pass.

[John Keeton]

Suffice it to say there are many highly skilled and experienced turners that would feel differently regarding the use of chucks and the necessity of a 40% tenon. For what it is worth, I agree with them.

[Dennis Ford]

I have done many pieces with a tenon less than 40% of diameter (I have also broken off a few tenons). I certainly would not expect anyone to stop using a chuck. I do believe that a faceplate is a better choice on some pieces and that making a decision on which to use requires experience and judgement more than it does "rules of thumb" like 40% of diameter.

[Reed Gray]

Well, I would spend a lot more time with turning my bowls if I did not use chucks. I never use a tenon unless I am turning end grain, or hollow forms. I use a forstner bit to drill a recess on the top of the bowl blank to mount it for turning the outside of the bowl, and turn a recess for mounting it so I can core and finish turn it. I haven't used a face plate in years. With a properly made recess or tenon, you can get a really secure grip, the key is the 'properly made' part. Angles of the tenon/recess should match the angles of the chuck jaws. Depth of tenon or recess, not more than 1/4 inch, as in deeper is not better, and you do not get a better hold if you bottom out in your chuck. Size for best grip is very close to the open/closed size of your chuck jaws. square shoulders. You can safely turn a 12 inch bowl with a 3 to 4 inch tenon. The rule of thumb I suggest is 25% minimum, and 33% is better. You can do it with a 2 inch tenon, but that is master class, and more 'care' is needed because any catch can send the piece flying. I turn and core 14 to 16 inch diameter bowls with my big Vicmark chuck in a 2 5/8 inch wide recess, no problems. I turn at higher speeds, and really hog the wood off. As I have said before, I worked my way up to this/professional driver on closed course, do not attempt! Well, you can work your way up to it, but this is not for every one, and you do not need to turn like I do to have fun, and be safe.

I do not use glue blocks. If I did, I would only use on dry wood, and with Titebond type glue, with flat, mating surfaces, and I would let it dry at least 24 hours. I would never trust hot melt glue, though some do. I would not trust thick or medium CA glue, though some do. If I was to try to glue a piece on end grain wise, I would turn a small tenon on the wood, and a matching recess on the waste block. I have found a good tenon holds just as well. Size here matters, bigger tenon that matches the chuck jaws closely holds fine, depending on the piece, meaning short distance. A 4 inch tenon will hold well out to 6 or maybe more inches, but beyond that, you will get vibration. If you use a face plate on end grain, and I never will, the screws/lag bolts are entering the grain in the same orientation that would be used if you were splitting the wood, which is the same reason why I would never use a recess on end grain. You can get away with it, if you pre drill holes, and angle/toe nail the screws in as many different directions as possible. Again, going at an angle through the grain rather than straight into it holds way better.

I don't like turning anything between drive centers, especially bowls, and not even spindles. Most of the time with spindles, I will turn a tenon and use my chuck, or grip the square piece with my chuck jaws. It just holds more securely.

As 'Pat's Fan' over on Woodnet forums says, "When sphincter tightening exceeds chuck tightening, you have a problem."

robo hippy

[Curt Fuller]

Ned, over time you harvest a lot of different ideas from different turners. Along with that you gain tons of knowledge from your own personal experiences. Lyle Jamieson is someone who truly knows what he's doing around a lathe. But as they say, there are many ways to skin a cat. I like to keep all the options open and try to stay away from the concept of 'always' and 'never'.

[Prashun Patel]

I am no pro, but I have made about 200 bowls with diameters Ben 10 and 12 inches. All tenons have been between 2 and 2.25 inches in diameter. Not one has snapped. A good many of one have been more than 6 inches deep and have weighed probably more than 25 lbs.

[Sean Hughto]

My comment is that's BS.

[neil mackay]

In order of holding power he rated face plate with many screws #1, glue block a close #2 and chucks a very, very distant #3..... said he hasn't used chucks in 20 years due to this.



This is a fairly contentious area for turners as it involves personal choice.
I can only speak from my own experience over 40 years. When I started chucks didn't exist and it was face plate stuff and I for one welcomed the day chucks came on the scene, It made my life so much easier .

But with anything it has its limitations and we have to know and understand these limitations and to generalize one way or another for and against anything can be dangerous.

I use pretty well all methods at different times and much depends on what I am turning and what the timber is ie I probably wouldn't swing a 16" Norfolk pine blank on a screw chuck.

But chucks for me have greatly changed the way I do things and I see no reason to eliminate them from our repertoire of tools. But then we are all given to personal choices and Lyle has his reasons of which are backed up by many years of experience.

What we have to do is take it on board and work out what works for each of us individually. In Australia we have some incredibly hard and tough timbers that lend well to the use of chucks. But not so good with screw chucks and glue blocks do require some sort of epoxy glue rather than the usual PVA etc and pretty much everything can be put on a faceplate.

So for me its horses for courses

[Eric Holmquist]

To chuck or not to chuck -- that is the question
Whether tis nobler in turning to suffer the faceplates and glue-blocks of old skool turners
Or to turn tenons against the advise of greybeards
And by opposing learn something new. To hollow, to core and more.
And by core to say we end the heartache, and the thousand natural shocks
that exotic wood has cost us...

Or perhaps some kid named Chuck shook down Lyle for lunch money in middle school and he never got over it.

[Dale Miner]

Or perhaps some kid named Chuck shook down Lyle for lunch money in middle school and he never got over it.


LOL

Liked the poem too...

[Dick Mahany]

To each their own............. Personally, I have turned a variety of items where I didn't use a chuck. But for so many things, I'd be lost with out them. They are just too versatile to be overlooked. I use mine extensively for turning lidded boxes, hollow forms, chucking square blanks in between the jaws, holding a home made velcro backed disc sander, driving friction chucks, holding jumbo jaws, and an occasional bowl or two and so much more. For me, they save a lot of time and I consider them indispensible. Sound like I like chucks ;) ?

[Richard Jones]

I turned some paperweights last weekend with just the vacuum chuck............probably 80% of the p/w was getting sucked.........

Do I get double word score?

Seriously, I use chucks daily. Roughed out 6 cherry bowls this afternoon, alternated between a 50mm and 100mm jaw, couldn't tell any difference, and I am very aggressive. I've only had a couple of tenons break over the years, and invariably the wood has been punky or cracked. No chuck, regardless of size, would have held it.

[Faust M. Ruggiero]

Since I start all my bowls between centers I don't have occasion to mount an unbalanced piece in a chuck. I usually move from centers to the chuck for hollowing a bowl. For a moment, let's not focus on Lyle's 40% rule. There are very good reasons to mount to a faceplate after truing the blank and aligning the grain between centers. First of all, it is still the most secure way we have to mount a bowl and will produce the least vibration. Secondly, you don't have to true the piece as you normally do when moving from centers to a chuck. Years ago. before vacuum chucks became commonplace, the screw holes had to be covered. There are lots of old bowls with plugs or felt hiding mounting holes. That's no longer an issue for vacuum owners or folks who use other means to finish the bottoms. I wouldn't want to do without chucks but I can understand Lyle's comment. I have had tenons break while coring a large blank. I now mount all blanks 16" and larger on a faceplate. Sure, it takes a couple minutes longer but I feel like it is time well spent.
faust

[Harry Robinette]

Most everyone has the idea to each his/her own. But on that note I have seen allot of changes in just the 13 years I've been turning. Chucks are being used as a catch all for turning everything. There's a time and place for all the different holding systems and allot of the new turners don't know anything about them. All you hear is,get a chuck first then you can turn anything. But it should be, you can turn anything and later you can get a chuck. If any of you get a chance read Doc Greens book about holding wood you'll be amazed.

[Steve Schlumpf]

To chuck or not to chuck -- that is the question


Dude.. Too funny! I appreciated the laugh!

All I have to say on the matter is that this is one person's opinion. Take this info and what you have learned from others and make your own decision as to what works best for you.

For me personally, everything I turn, I turn using a chuck... including hollow forms.

[BILL DONAHUE]

First, thanks for mentioning that Lyle Jamieson has Youtube videos. Looked at several and they're excellent. As for the chuck debate, he is quoting Dale Nish for the 40% rule and between Lyle and Dale they certainly have more experience than I'll ever have so I wouldn't be so quick to write off their advise. Nevertheless, we all march to our own tune and that's probably why so many woodturners get injured. The only time I had a problem with a chuck was with pretty green Norfolk Island pine which is soft and fibrous. Went to a faceplate and it held well. Have never had the guts to use a glue block on a hollowed form and probably won't in the future, no matter who recommends it.

[Michael Mills]

The best I can say is keep studying and exposing yourself to ideas. For example, I believe in Lyle’s video he starts with the tool rest parallel with the bed, Grumbine says to never do that..start perpendicular, Jordan says to start at 45. If done properly they all work as evidenced by their success.
If the youtube is like Lyles full video he goes into great detail about preparing for the glue-up and maintaining good transfer of power.
If you haven’t seen it, here is a very good video by Mike Peace on “holding” methods… about and hour and half.

www.youtube.com/watch?v=aUXil-5dEeo (http://www.youtube.com/watch?v=aUXil-5dEeo)

[Sid Matheny]

By the numbers 40% may be correct, but also by the numbers a bumble bee can't fly. :rolleyes:


Sid

[Peter Blair]

Eric, you are a riot! LOL

Best laugh I've had in days. I agree with others, that any time I hear "only" I immediately get my hackles up. I too have turned hundreds of bowls to 15" and have never had a tenon break off. I guess it depends on how you approach the cut. Lyle is a very well respected and excellent turner but his philosophy doesn't alway meet with what others are doing.

I do question his glue block theory as apparently he turns to finish, green. I myself have always had trouble getting glue to adhere properly to wet wood. . . .

[Mark Hubl]

Chucks have been a giant leap forward. Heck when I had my first turning lesson we turned between centers, and greased the tail end. Are chucks great for everything, heck no. Just another arrow in the quiver. I find myself using more glue blocks lately with chucks and face plates. If I did lots of big stuff or deep stuff I would think I would use chucks less. Lyle does a lot of big deep stuff so I can see why the other methods of holding/driving are more appropriate for him. Lots of ways to do it, having options is good, knowing when to use them makes the work easier and safer.

[robert baccus]

Like you guys I really dislike the words never/always. There are many ways to grab wood and all have their place. I turn a lot of green wood and really distrust tenons on heavy green pieces. They are fine on dry wood of reasonable sizes and balance. Never say never to glueblocks--I turn many vases of green wood in the 50 to 100#+ sizes and use thick CA on a strong GB mounted on a single screw in a Nove 2 chuck. The stuff holds great on wet wood--took me years to go that heavy on a single screw though. These pieces are 10 to 14" long and hollowed which really tries a mounting system. Easiest for me--mount the blank on a faceplate--rough out and mount a glueblock using the tailstock and square the GB--reverse onto a screw until ready to sign. I was turning before they brought out the first chuck---a nova which i promply bought. I guess i use several together methods on the heavy long wood. Chucks are great used properly.

[Montgomery Scott]

His opinion is not only wrong, but potentially dangerous. A chuck has the greatest holding strength when the tenon or recess diameter is the same as that of the chuck when the jaws are fully closed. The more the jaws are opened the less contact area there is; with a tenon you have four points of contact on the inside of the jaws and for a recess you only have four points of contact. This presents very little resistance to fiber shear out.

[Pat Scott]

I'm in the 35% to 40% diameter tenon camp. The bigger the better, especially when coring. I wouldn't dream of turning a 12" or larger bowl on a 2" tenon. I see You Tube videos of people doing this and just cringe. This is why I have different chucks with different size jaws (my largest jaws are 7"). With a larger tenon you have more support and less chance of vibration.