Expanding mandrel choices

I'd like to pickup some expanding mandrels that are on sale.
Enco has 2 different styles, one goes off sale this month
and the other one goes on sale next month.
Which would be better, the 2 piece one which looks like a
press fit, or the one that uses a screw to tighten.
I don't have an immediate need, other than a case
of toolitis.
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I got lucky on a set of KO Lee expanding mandrels some time ago. They're like the 2-piece ones. Thing is, those go between centers, so you can remove the part on its mandrel and replace it exactly. I also suspect they're more precise.
Reply to
Grant Erwin
I'm only seeing your messages as quoted by others. This suggests that either you have the date mis-set (perhaps in the future) on your computer, or you are posting through a blocked site, such as "alt.net". If the latter, you are stuck, as there are too many kooks posting from there for me to open that one back up again.
Anyway ...
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They are -- especially for longer bores. The screw-adjust type is captive at one end, so the parts are bound to tilt a bit as you adjust the screw, so they will grip harder at one end than the other. The two-piece ones slide a tapered ID along a tapered mandrel, so the OD remains parallel from end to end as the size is changed.
Also -- the screw-adjust ones appear to be designed to be turned on the lathe to just under fit, and then adjusted to grip from the inside. This would make the fit a bit better, as long as you didn't have to move the ID very much, but that means that it is better for use on a project involving many pieces, as each time you use it for something else, you will wind up machining a bit more off of it to make it fit. The two-piece ones have a wide adjustment range, and both parts are hardened, so you really *can't* machine them to fit -- but you don't need to, either.
Enjoy, DoN.
Reply to
DoN. Nichols
Bummer, I always value your input. I've been posting through my ISP instead of google. Clock is set correctly.
I think I'll go with the 2 piece ones. They sound like they would center better and be easier to use. I assume they could be used on shorter parts also.
Thank you Grant & DoN Wayne
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