[trose]

what about a screw feed?

[jacquesm]

I've tried that but it kept damaging the pieces. Is there a way to 'tame' a screw feed so that it doesn't eat up pieces that are sloped between the tube and the screw?

[javajosh]

A coat of teflon could be sufficient for the taming of the screw.

[londons_explore]

Make the outer edge of the screw have door brushes[1]?

[1]: http://www.formseal.co.uk/

[jacquesm]

That is an excellent idea. And then elongate the screwthread spacing as it gets nearer to the drop off point to separate the pieces further.