I'm thinking of making a Straka chuck, and have read the posts on this forum as well as Alan Lacer's article - but I see a potential problem with its use. I have been reasonably successful using jam chucks for both natural and cut edged bowls, but it is a bit of a pain to get the centering just right. I can see the greater flexibility of the Straka chuck, and that one can make a more exact centering - but the donut prevents one from blending the outer surface of the bowl on the lathe. With a jam chuck I can shape the bottom then lightly shear scrape the outer surface to blend it with the upper part, then finish the whole outer surface with light sandpaper. That seems impossible with the Straka chuck.

It's possible that the accuracy of centering is so good with the Straka that the blending isn't necessary, and that the final sanding can be done off the lathe - but if one is just moving a problem to another part of the process I don't want to make the effort to make the Straka. I'm on a PSI 12" midi and make both small forms (particularly Ellsworth style "spirit forms") and bowls up to the practical limit for the 12" lathe of about 10". I mainly use green wood off the tree, but sometimes use kiln dried "plank wood". BTW, I don't reverse chuck my "spirit forms", I use a glue block and once it is hollowed I finish the bottom at the headstock end with a detail gouge. That leaves a small "flat" to be made so it will sit upright, and I do that with a small disk sander.

So I ask this fine forum to tell me why I should make a Straka chuck - I think you will have good answers and that I'll end up making one. I can see that it is a lot easier to re-center a natural edged bowl with the PVC extention, although I do the same with the jam chuck. The problem with the jam chuck that the point on the revolving tail center (and I use a cup tail center) chews up the wood as one readjusts it - making it very difficult to get an exact recenter. If the recentering with the Straka is so exact one doesn't need to blend the outer surface on the lathe then I'll make one.