Is this normal?

[mekanik]

I seem to recall you can get 3 jaw chucks that have adjustment in the backplate, you put a short mandrel in the jaws and dial out the runout then lock it.

Regards
Mike

[m_c]

I seem to recall you can get 3 jaw chucks that have adjustment in the backplate, you put a short mandrel in the jaws and dial out the runout then lock it.

Regards
Mike

I don't think I've ever seen a scroll chuck with that kind of adjustment, but I have seen collet chucks with that kind of setup.

I should have said independent 4 jaw in my original post, but Magicniner has already clarified that.

You can improve accuracy by grinding/boring the jaws (remember you need to clamp them onto something near the correct size first, to preload them, and standard jaws are generally hardened to some extent), but as I mentioned, that accuracy is likely to vary over the scroll. Scrolls are rarely a precision component, and accuracy varies over the scroll.