BOWL HELP

[triw51]

I started this splatted pecan bowl. Turned the outside and cut a tendon. When I turned it around I kept the tail stock up because it was heavy and still not quite balanced. As you can see in the pictures I hollowed around the center core. I had a catch and both the tendon and center core broke off and the bowl went flying.
I need to cut a new tendon the inside is not level on the bottom so I don't think a jam chuck would work. The jaws on the chuck I have open about 2 to 2.5 inches. Any suggestions?
Thanks in advance.

 

[scottsheapens]

Use a set of Cole Jaws with the tailstock up to recut a bottom tennon. Place the inside of the bowl toward the Cole Jaws.

 

[Wingdoctor]

If you have enough thickness in the bottom, I have used a large forester bit, 2" plus, to make a recess in the bottom exterior and to use the chuck in expansion mode to grasp the blank. A block of wood on the inside with the tailpiece center holding it in place plus the expanded chuck should give you enough grip to finish turning the bowl.

 

[Cwalker935]

Can you sand the bottom flat and glue on a waste block?

 

[bobleibo]

..

How about a donut chuck? These are not my pics, but I have a couple - big and small - and they work great for things like you are talking about. Very easy to make.

 

[jjjaworski]

Mount a disc on a faceplate- (mdf, wood ) large enough to cut a recess to hold the bowl at the top rim.

Once you true up the disc you can cut a shallow recess that will hold the rim of your bowl.
Glue some small scraps of wood to the disc that will capture the bowl using hotmelt glue, wood glue, CA . Something that pushes against the outside of the bowl to keep it against the face plate disc. You want to be able to remove the waste blocks and not harm the bowl exterior.

Use light cuts to do a minimal cleanup on the bowl bottom so you can glue a waste block for the new tenon. Your tailstock can supply the pressure for this.

Once you have the new tenon on it can be turned to fit your scroll chuck. Reverse the bowl and finish the inside.

The waste tenon can be then turned off.

 

[pfbarney]

Agree with JJJ.

I've ran into similar situations and used a piece of 3/4" ply wood mounted on a face plate. Used my parting tool to cut a groove into the face of the plywood so the bowl fit tightly and just used my live center to support it while I cleaned up the bottom. I saw Mike Mahoney use the same method in a demo last year and thought he was just showing off, but it actually comes in handy.

I like JJJ's idea of using some scrap blocks for additional support. You may even be able to screw something on to the plywood/MDF to capture the edges of the bowl.

 

[alankulwicki7]

Make yourself a donut chuck. That would work great in this situation but they also work wonders for finishing off the bottoms of bowls.

 

[Dan Masshardt]

Lot of good ideas here. There's also no reason a jamb chuck wouldn't work. Just make space in the chuck for the inside part or sand it flatter.

Make sure you use the tailstock is all and cut a new tenon.

 

[low_48]

You've got a pretty big crack in the rim with the look of an inclusion or something above it in the picture. BEWARE! Get it too thin and that whole segment might pop! Especially when the tenon blows completely off like that.

 

[SDB777]

I'd be more concerned as to why the jaws didn't hold....


Scott (better tenons are always better) B

 

[low_48]

I'd be more concerned as to why the jaws didn't hold....


Scott (better tenons are always better) B

Looks like the jaws held just fine. The wood failed.