Indeed, and virtually guaranteed to be off when using styrene. My main parting routine consists of taking out the work piece, switching to a parting tool, setting it to a known distance ("zero"), position the to-be-parted piece against the tool, fix, set the right position & part. This does work with the 3-jaw chuck but not perfectly. Styrene is very soft, while parting the piece is typically pushed a bit away from the parting tool and the rear surface is not always flat anyway. I used the collet set for the Proxxon as well but for some reason it doesn't work as well as I'd like. The newer collet set uses the ER type, the version I have does not... perhaps I should try the new version, e.g.,wefalck wrote:For model work I almost exclusively use collets. They are so more convenient and a lot safer than messing around with a 3-jaw-chuck. Also, if you have to re-chuck a part, chances are much better that it runs true in a collet - in an 3-jaw-chuck it almost certainly will not.
http://www.hobbiesguinea.es/en/proxxon- ... 250-e.html
The main advantage other than improved holding is not risking the chuck hitting your hands or other tools. I always apply a file rotating the lathe in the opposite direction; if you go with the turning direction you may catapult the file in your eye when it hits the jaws (which would be bad, because files corrode easily). This risk would be reduced (but not gone) with the smooth collet chuck.
So you'd have to use the single-slotted collet that typically has three slots?wefalck wrote:One should also add that they double-slotted, like ES-collets, which are really meant for tool-holding, not for work-holding.



















