Step jaws?

[Dan Masshardt]

I only have standard 2" jaws and am turning wanting to turn bowls in the 10-12@ range and need bigger jaws.

I'm thinking of ordering the step jaws rather than 4" jaws for my next purchase.

Does this seem misguided?

[Roger Chandler]

I only have standard 2" jaws and am turning wanting to turn bowls in the 10-12@ range and need bigger jaws.

I'm thinking of ordering the step jaws rather than 4" jaws for my next purchase.

Does this seem misguided?

I have step jaws on one of my 7 chucks.........for bowl turning, I would much rather have bowl jaws, as the extra material used to make up the step jaws at times get in the way of making cuts close to the bottom tenon.........unless you use the outside or biggest step. Still, the other steps on the inside will prevent getting much length on a tenon, and that is the biggest reason I like bowl jaws or especially like the power grip jaws for bigger bowls............with the Nova chucks. The biggest place I use step jaws is for holding a square piece of stock to start out.............bowl jaws are a better choice for bowls or the powergrip jaws.

[Michelle Rich]

yes. misguided, in my opinion

[Dan Masshardt]

What is the right size jaws for 10-11" bowls?

4" jaws is what I'm thinking?

[Steve Schlumpf]

Dan - I use my 2" jaws for large bowls and hollow forms all the time and prefer them to the 4" jaws. Course, that is my personal preference and if you want a larger foot area, then the 4" would probably work just fine for you. I have step jaws but only use them to hold small items. Like Roger mentioned, the steps tend to get in the way most of the time.

[Thom Sturgill]

If your choice is between 4" jaws and step jaws I'd say get the step jaws. I have the 4" jaws and bowl jaws, but not the step jaws. I'm not too sure how handy the inner steps would be unless you have the wood to eliminate whatever is in the chuck from the design, or you are gripping a tenon on an otherwise finished box. In that case it would not matter that you cannot cut near the step that is holding the piece. So they should provide SOME additional flexibility over the straight 4" jaws in that they would save some jaws changes. I have been thinking about buying a set as I do turn a number of boxes and goblets.

I'm in the 'recess' camp for the most part, at least for largish items, unless I feel the need for a faceplate.

Unless you are using the power jaws or bowl jaws I do not think a tenon gives as good a grip and it is NOT necessary to grip so tight that you split the wood (or crush a tenon and I've been there, done that). Nova bowl jaws are only 2" inside but 3" outside so a wide base for the tenon or recess, plus deep serrated jaws. Power jaws are deeper, but not as thick. I'm not sure about the diameter.

[Dan Masshardt]

Hmm. So maybe I'll just stick with my standard jaws for now. I haven't had a problem so far.

I've used both tenons and recesses.

[Dan Masshardt]

Why would the 4" jaws not be called bowl jaws?

I'm talking about dovetail jaws the same as the 2" ones just bigger.

[Hayes Rutherford]

Step jaws work well when you are turning lots of footed bowls with the intention of turning the base to completion before turning the inside. There is usually a step that that does very little damage to the foot regardless of its size, and the profile of this type bowl is close but doesn't contact the larger steps. Popularized largely by the efforts of Richard Raffan and Vicmark, for some good reasons.

[John Keeton]

I use Nova 2" jaws for 95% of my work and wouldn't hesitate to turn a 12" bowl with them. On the other hand, I am not an overly aggressive turner. Having seen Reed Gray's biceps in person, my guess is that he probably prefers larger jaws!

[Thom Sturgill]

Why would the 4" jaws not be called bowl jaws?

I'm talking about dovetail jaws the same as the 2" ones just bigger.

I think Nova markets them differently because they needed a name specific to the design and already used 'power jaws'. Most of the larger diameter jaws are used for plates and platters, though some turners do use the large jaws for bowls. The 2" jaws were labeled as '50mm jaws' and the similar larger just by diameter also. Only specialized jaws seem to have a more descriptive name.


As an aside, I saw a demo where Ashley Harwood started between centers, trued the tailstock end and turned a recess on what would be the bowl top. this let her orient the wood for best grain pattern. She then reversed into 4" jaws to turn a tenon on the base and shape the outside. This gave her full access for her push cuts without having the tailstock in the way. Then she reversed again into a chuck gripping the tenon to hollow the bowl.

[Michael Mills]

I have the Powergrips and they are nice jaws but maybe a over kill for 10" -12" diameter unless it is hollowform.
One set not brought up, and they are probably my favorites, are the 70mm jaws. They are a lot less expensive also. This link shows the current jaws. Note there is a 75mm jaw set also but the spigot size is almost identical to the 50mm set so you don't gain a lot IMHO with that set.
http://www.teknatool.com/products/chucks/10912_Nova%20Chuck%208pp_web.pdf

[Bill Boehme]

I don't know anything about Nova chucks and jaw sizes, but for my Oneway Talon chucks, I use the #2 jaws for almost everything. For heavy hollowforms I use my Stronghold chuck with either #3 or #4 jaws. For really large stuff over 20 inches in diameter, I use either a faceplate or my Vicmarc 120 with 7 inch jaws.

[Reed Gray]

Tenon or recess size depends on bowl size. For a tenon, you want some where in the 1/4 the diameter, so for a 12 inch bowl, you want a tenon around 3 inch diameter. You can get away with less, but if you are coring you need some thing bigger. If, when you reverse, you use the tailstock to hold the bowl into the chuck while you remove most of the interior, that will relieve a lot of stress. A 2 1/2 inch tenon with jaws that close down to 2 inches should be okay on a 12 inch bowl, but I wouldn't go much bigger on a bowl with those. I use a recess. My big chuck has jaws that are 2 5/8 inch diameter. I can turn and core bowls up to 14 inch diameter with them no problem. Over 14 inch, it still works but I have to be more cautious. I do have dove tail jaws which does give a better grip.

As for step jaws, I have a set or two, and they sit dust covered in a drawer. In order to get the steps, they are high on the outside, and low on the inside, and actually get in the way. Having a set of 3 and 4 inch jaws works better. Of course, having a chuck for each set of jaws works too.

robo hippy

[Jeffrey J Smith]

Step jaws work well when you are turning lots of footed bowls with the intention of turning the base to completion before turning the inside. There is usually a step that that does very little damage to the foot regardless of its size, and the profile of this type bowl is close but doesn't contact the larger steps. Popularized largely by the efforts of Richard Raffan and Vicmark, for some good reasons.
I've got the Raffan step jaws, and the workflow that Hayes outlined is exactly where they really shine. Trouble is, I rarely complete the outside profile all the way to through the foot before reversing and hollowing, preferring to finish the bottom last with a vacuum chuck. As a consequence, they get very little use. A while back, Richard addressed this problem in his article on chucks in the AAW Journal and, after reading, I re-mounted the step jaws on a spare chuck and gave it yet another go. They are still gathering dust rather than generating shavings.

[Dan Masshardt]

Maybe one of the many of you who never use your step jaws should give me a good deal so I can try them for myself. :-)

Seriously, I really appreciate that so many people jump right in to offer advice on these questions.

You are all really knowledgable.

[robert baccus]

Easier still is to start a bowl on a single screw and turn the outside and bottom to suit your mounting method. I haven't used a jaw larger than 2" in many years. I do use screw on 1/8" thick dovetail rings a great deal. Best money I ever spent on turning toys. It allows mounting and dismounting a bowl or vase in seconds with one hand. Especially when finishing I spray on the lathe and with one finger in the vase mouth and wrench in the left hand the piece can be removed in seconds to clear the lathe. Single screws should be used in side grain and firm wood only.

[Harvey M. Taylor]

I agree with Reed and Mike Mahoney. He suggests 40%of the diameter. max