Cole/button jaws or ......

[Graham]

make my own. What do you use or do when reversing bowls etc ?

[Les Symonds]

Much depends on the size of the bowl and the type of edge that it has.
For natural edged bowls, which couldn't beheld in cole jaws (or anything similar) I have a big lump of wood mounted in my chuck, which I then skim the face off so that the inside of the bowl sits nicely on it, then I face it with a soft cloth, slip the bowl on and bring the tail-stock up to it. If I don't want the centre on the tailstock to mark the wood, I have a range of firm, rubber/plastic objects ( like tap washers and door-stops) that I use to press the bowl in place. Simple friction then provides the drive.
For clean-edged bowls I use cole jaws up to their maximum diameter, but above that I have two other types of reversers. One is very simple. It's a huge disc of plywood with excentric circles marked on it at 1cm intervals.  have a few different sets of 'buttons' made from scraps of wood, that I bolt onto the plywood at relevant diameters, to sit the bowl or platter into. This comfortably holds platters and large bowls up to about 28" diameter.
I also have a special, home made chuck that is based on two disks of plywood bolted together at the centre point. There's a series of curved grooves routed into them, one set swinging clockwise, the other anti clockwise. Buttons for holding bowls or platters are then bolted on, through the intersections of the two slots. You can see it, and other ideas, in this thread of Bryan's.
http://www.awgb.co.uk/awgbforum/index.php/topic,2243.0.html


Les

[bodrighywood]

I have a couple of wooden face plates in different sizes that are on spigots so can be held in the chuck. They both have big lumps of foam as in old mattresses stuck on them and so when I hold a bowl against them it doesn't matter if the rim isn't round, natural edge or warped.

Pete

[TWiG]

I use the between centres technique , usually with a rounded lump in the chuck and I place some router mat , between the 2 surfaces , helps grip and does not mark . I do something similar with hollow forms as well , then hand finish the little "nib" left .. carve off with chisel and then sand by hand or drill / disc combination  ..simples !...

[malcy]

I almost always use a donut chuck. I have a large 19mm thick MDF disc with a faceplate or faceplate ring mounted onto it and turned true. Another similar disc is attached using 4 M12 nuts and bolts fitted equally around the discs within and inch or so of the edge. This second disc has an opening turned out to fit the part to be reversed such that it grips the piece at a suitable point. (I have a few discs with different size openings). I also use a round mouse mat to  soften the grip onto the top edge of the piece. The piece is mounted with the opening over it loosely and then it is centred using the tailstock. Once centred the bolts are tightened to grip the piece. You can use a piece of cloth or foam between the opening in the disc and the piece so as not to mark it, but I have found MDF is usually soft enough not to make any effect. This method I have found to be the most secure of all. Just make sure that the heads of the bolts are on the side from which you will be turning, and that tool rests and hands/fingers are well away from them as you turn the base of the piece. Hope this helps. Malcolm.

[Graham]

I almost always use a donut chuck. I have a large 19mm thick MDF disc with a faceplate or faceplate ring mounted onto it and turned true. Another similar disc is attached using 4 M12 nuts and bolts fitted equally around the discs within and inch or so of the edge. This second disc has an opening turned out to fit the part to be reversed such that it grips the piece at a suitable point. (I have a few discs with different size openings). I also use a round mouse mat to  soften the grip onto the top edge of the piece. The piece is mounted with the opening over it loosely and then it is centred using the tailstock. Once centred the bolts are tightened to grip the piece. You can use a piece of cloth or foam between the opening in the disc and the piece so as not to mark it, but I have found MDF is usually soft enough not to make any effect. This method I have found to be the most secure of all. Just make sure that the heads of the bolts are on the side from which you will be turning, and that tool rests and hands/fingers are well away from them as you turn the base of the piece. Hope this helps. Malcolm.

I really like the sound of that and it sounds relatively easy to do........ does plywood turn easily ? I would have thought it would splinter all over the place.

[The Bowler Hatted Turner]

One of my favourite ways of turning the bottom off bowls is by using a jamb chuck. MDF works very well but be careful of the dust and to prevent it de-laminating I put a ring of screws around the outside as a precaution. I do use cole jaws and have in the past "extended" them, but very carefully. It is always worth remembering to mark the centre of the bottom of your bowls as an aid to remounting.