Set up for chuck expanding mode

[Tiger]

I've had variable results when using expansion mode on my chuck. What is the best setup when using expanding mode ie how deep do you make the recess of your bowl etc to get the best purchase? How critical is the angle of the recess, does it need to be dead on?

[rsser]

Tiger, this subject was covered exhaustively a month or two ago. Try a search.

[Tiger]

Tiger, this subject was covered exhaustively a month or two ago. Try a search.

Tried Chuck, expanding jaws, expansion mode and nothing has come up. Been back 3 months manually and have not found this exhaustive coverage.

[rsser]

Here ya go then:

http://www.woodworkforums.com/f8/aust-wood-review-article-bowl-mounting-114344/

[Tiger]

Thanks, Ern, that is indeed a good thread. I'd never have found it with the typical search criteria though, as I'd have used words like holding, contraction etc.

[mick61]

G`day Tiger I don`t like holding pieces in expansion mode they tend to fly around the workshop. Glue a sacrificial piece of pine to your blank and make a spigot with that .Much safer my two cents.
Mick:D

[rsser]

Mick, go back over the linked thread before you share your two cents.

Then if you reckon it's worth spending I'll send you my bank details ;-}

[cultana]

Mick, go back over the linked thread before you share your two cents.

Then if you reckon it's worth spending I'll send you my bank details ;-}

Thanks for that link. Interesting thread and the side track onto scrapers was useful.
One thing I did not quiet follow was how Ken mounted his piece. He mentions a small face plate. Does that mean face plate or face plate ring?
I was also a bit surprised when he mention mounting on ply not a piece of timber. I presume there was a reason for this difference.

I follow the intent of Ken's approach but I have reservations on it being functional with green timber that would start to dry out and split while the glue sets. Add the time delay during turning etc and one could end up with a useless piece.
I have lost pieces just in the turning phase due to this drying and splitting.

Mick:
One question, why bother to glue on a sacrificial piece and then stick that in the chuck when a face plate would be far safer and you don't have to bother trying to turn a spigot on it as well. All extra time for little gained ?

[rsser]

Re Ken's posts, I assumed he meant a sacrificial block and faceplate.

[oldiephred]

One question, why bother to glue on a sacrificial piece and then stick that in the chuck when a face plate would be far safer and you don't have to bother trying to turn a spigot on it as well. All extra time for little gained ?<!-- google_ad_section_end -->

IMHO: You can use hot melt glue, then no delay time (not much anyway)
Faceplate only = screw holes to deal with later.
Turn a spigot (tenon)= using good material that could be part of the finished product.

good luck

[rsser]

Why use a sacrificial block? Rare wood; tight design within the blank dimensions; small piece that can quickly be parted off.

I hate to try to speak for Ken but IIRC he mounts only at what will be the foot and does the inside and most of the outside from there. Happy to be corrected though.

[robo hippy]

For me, it was why use a face plate and screws, screw chuck, or waste block when you can use your drill press to make a recess in the top, turn the bottom, cut the recess, reverse, then turn and core the inside? The chuck never has to come off the lathe, just turn, turn, turn.

The advantage of dove tailed jaws is that it is a mechanical joint, just like the common dove tailed joints in flat work. The chuck is adjustable to work on the inside or outside of the joint, and the angle of the jaws gives an advantage to straight jaws. The ribbed jaws will hold better than straight smooth ones.

robo hippy

[RETIRED]

Why use a sacrificial block? Rare wood; tight design within the blank dimensions; small piece that can quickly be parted off.

I hate to try to speak for Ken but IIRC he mounts only at what will be the foot and does the inside and most of the outside from there. Happy to be corrected though.You are correct Ern.

Ken mounts the scrap to a face plate and virtually finishes the whole lot and then only has the foot to do, generally in a jam chuck.

[rsser]

Thanks .

The order of work with bowls that I was taught was to mount in the waste of what was to be the hollow, shape and finish the outside inc a foot to expand the chuck into for step 2, then in step 2 reverse chuck and hollow and finish the inside.

One key drawback with this method is that if you want to go thin, your gouge is pushing the bowl wall outwards generating all the probs with wall flex. Ideally, your gouge should be pushing twds the spindle.

So one way of dealing with this is to have left the outside shaped but unfinished; after hollowing and finishing, come back to finish cuts on the outside, and sand and finish.

[NeilS]

For me, it was why use a face plate and screws.... when you can use your drill press to make a recess in the top, turn the bottom, cut the recess, reverse, then turn and core the inside? The chuck never has to come off the lathe, just turn, turn, turn.



Used to drill recesses until faceplate rings became available. I find it just as quick to drill and power screw a faceplate ring as it is to drill a recess, and the chuck also remains on the lathe with a ring.

If you get into a rhythm with either method there is probably not much of a difference time-wise. Recess drilling can be done in batch mode, whereas most of us will only have a few faceplate rings, so these have to be done individually with each blank. I quite like this punctuation between blanks, a brief get to know you before I begin turning, but can see the logic/efficiency in batch processing.

I still drill recesses on natural edge bowls.

.....

[robo hippy]

I have never tried the face plate rings. I figured that my blanks weren't always truly flat, and that was probably a necessity for the rings. I do things by the batch (production), so not a lot of adjusting to do on the drill press.

Efficiency is intelligent laziness. Unknown author.

robo hippy

[NeilS]

I figured that my blanks weren't always truly flat, and that was probably a necessity for the rings.

Attach mine straight to a chainsawn face, so rarely dead flat and at times slightly stepped. Usually the rings just bridge any undulations which usually works and I keep some paddle-pop sticks handy and slip one or two under any very low spots, if required.

Anyway, I'm not arguing for one method over another, just putting the case for rings as a workable option. Clearly, after mounting many thousands of bowls via your method, Reed, the drilled recess is a very workable option for a production turner.

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