Vacuum Chuck Question
I'm making progress on setting up my vacuum chuck but have a question.
But first, let me show you what I've done so far. I have a *very* small shop so I built a shelf close to the ceiling and put my vacuum pump system up there to get it out of the way. Then I made a manifold so that I can use the vacuum pump for veneering or chucking. Finally, I include a picture of my spinner on the lathe. This was a challenge because the Jet handwheel does not have a hole in it, but I was able to drill a hole through it and attached the plastic wheel to the original handwheel. BTW, this is a "Joe Woodworker" spinner system.
But now my question.
I'm now ready to make the "chuck" portion of the vacuum chucking system. I can easily make a flat chuck but centering the bowl on a flat chuck is a problem and you can't do that with natural edge bowls. I've seen pictures of chucks that fit inside the bowl and these seem like a very good idea - they work for nautural edge bowls and they can provide some centering action if the chuck fits against the sides of the bowl towards the bottom of the bowl.
But this is where my question comes in. When I turn a bowl, I don't make it a standard size - I make it to fit the blank I have. If the bowl has vertical sides (not tapered), it seems that only one size chuck would fit it, something like a jam chuck. But I don't want to have a dozen or more vacuum chucks sitting on a shelf.
What do you do about this? Do you use the next smaller vacuum chuck that you have and center it on the bottom of the bowl? Or do you have some way of fitting an existing vacuum chuck to a bowl, like putting more rubber tape around it? Or is there some other solution?
Or do I just not understand how vacuum chucks work?
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