# Chucking



## jmurray (Jun 5, 2015)

Quick question. When you guys turn green bowls what kind of tenon do you use most?

I'm asking because I'm having trouble getting them back on the Chuck centered or straight? I have been doing a recessed tenon, should I switch? Are the moving that much when they dry that my recess is no longer centered?

Im using a little nova 3jaw


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## Jerry B (Jun 5, 2015)

if you remove from chuck to dry, yes most woods will move enough that it won't reseat
for double turning, best to use a tenon instead of a recess, make the tenon larger than normal, and true-up the tenon once you're ready to re-chuck & re-turn after drying
If you're turning to final thickness and then let dry, using a recess will work just fine (my preferred method)

depending on the species you're working with, will determine how much it moves when drying .....

Reactions: Agree 1


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## Nature Man (Jun 5, 2015)

Concur with tenon preference. I discovered this week that it is a good idea to make the tenon length to fit the chuck, if possible. I pulled out a couple of bowls I had rough turned a couple years ago with stubby tenons, and they both snapped off when I was trying to true up and finish the interiors! Both were honey locust, so don't know if that was also a factor as well. Chuck

Reactions: Like 1 | Useful 1


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## David Hill (Jun 5, 2015)

Can I complicate your thought process?
Once I get my blank round I use my square carbide to cut a 1/2 inch or so groove where I want my tenon to be. It can be either a "regular" or recessed--just depends on what I envision for the piece.
I use Barracuda (PSI) chucks that are good for both.

Reactions: Useful 1


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## DKMD (Jun 5, 2015)

I use a tenon for roughing rather than a recess, and I make sure to dimple the bottom with the live center. After it's dry, I jamb it against the chuck using the dimple. Then, I true up the tenon and the area near the tenon before flipping it around into the chuck.

Reactions: Agree 7 | Useful 2


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## Mike Mills (Jun 5, 2015)

I assume you are using a Nova G3 chuck ...
The following is what I do.

Whether I start with drive center, screw chuck, faceplate, or pin chuck I do as David K suggest and leave the dimple from the tailstock.
It doesn't matter if you are mounting with a tenon or a recess. If mounting with a recess you only have to remove enough material for the jaws to fit in, the center doesn't matter so the dimple stays. This dimple is the last thing removed after the final turning and finishing except for the bottom.

I typically go with a recess. If you are using the 50mm jaws and work through the "pi r squared" (giving an inch of wood surrounding the recess and Nova suggest) you will find there is 3 times the amount of wood to break away with a recess compared to a tenon.
This lessens as the base diameter increases.

I agree, when starting green make the tenon larger than normal to allow for warping. I used to make them about 3/8" larger. I now step down my jaws to allow a better fit at each mounting. For example I may turn green with the 70mm and finish with the 50mm or turn green with the 100mm and finish with the 70mm.
I find it just as easy to re-true a recess as to re-true a tenon. I always cut recesses at the absolute minimum diameter possible.

Reactions: Useful 1


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## NYWoodturner (Jun 6, 2015)

I use the exact same process as Doc outlined. I use it 99% of the time.


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## jmurray (Jun 6, 2015)

Thanks guys I'm back on track now


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## DKMD (Jun 7, 2015)

Mike Mills said:


> I assume you are using a Nova G3 chuck ...
> The following is what I do.
> 
> Whether I start with drive center, screw chuck, faceplate, or pin chuck I do as David K suggest and leave the dimple from the tailstock.
> ...



I'm curious about your method for recutting the recess... I always felt like the live center was in the way, so I'm interested to hear how you do it. It may be the chunky tail stock assembly on the PM lathe versus other makes and models comes in to play.

Reactions: Creative 1


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## DKMD (Jun 7, 2015)

Here are a couple of shots of what I'm talking about using the dimple.

Reactions: Like 2 | Useful 1


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## jmurray (Jun 7, 2015)

Thanks. That's the ticket.


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## Mike Mills (Jun 7, 2015)

With the Nova live center they have an extended point IF it is necessary that extends out about 1.5 inches. I did measure the diameter of the live center and it is 1.75". For a recess it can be a little tight for working area with the 50mm jaws but is no problem with the 70mm. I normally start with a secure mount (woodworm, faceplate, or pin jaws) instead of a drive center.

In your pic it appears it is mounted with a faceplate (?) so the tailstock can be removed to form the tenon or recess. You can always bring the tailstock back up to re-dimple. If a person forgets to re-dimple you can use your little center finder for the faceplate in the chuck to mark the center (pic -yes I know I took the pic with the finder inserted from the wrong side).

I also have a dovetail tool made from an old bench chisel. End is ground at 45* with my required 15* dovetail on each side. For a recess, the shaft of the tool is presented 45* to the tool rest and pressed in the face. For a tenon it is presented parallel with the bed. A slight push or pull perpendicular to the ways will make the dovetail.

You can use a 1/2 carbide cutter or other tools described to cut the width of the recess then trim up the dovetail with a small skew.

Reactions: Like 1


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## DKMD (Jun 10, 2015)

Mike Mills said:


> ...
> In your pic it appears it is mounted with a faceplate (?) so the tailstock can be removed to form the tenon or recess...



Thanks, Mike. That little scraper tool looks handy.

The blank in the picture is actually a dry bowl roughout that jammed against the chuck, so the tail stock is necessary for cleaning up the tenon. That's the situation where I've struggled with trying to clean up a recess that has warped on a roughout... That little tool you showed seems like it would help!


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