3 Jaw Lathe Chuck

UPDATE
Durwin Pye has sorted out the Scad file so it is now brilliant, Thanks,
I have added it to the list of files -not for the faint of heart-

After printing some other designs and finding they did not work for me, I decided to have a go myself, So here it is, Please beware, I have made allowances for my own printer so I take no resonsibility if it doesnt work for you.
Also, to state the obvious, this is a plastic chuck, it has its limits!.
101mm diameter, 59mm thick plus 25mm jaw height.
With thanks to;
-Parametric Involute Bevel and Spur Gears by GregFrost
http://www.thingiverse.com/thing:3575
-Customizable Spiral Generator by walter
http://www.thingiverse.com/thing:58406
for the hard work
UPDATE
I have printed and tested (sort of) different jaw materials And added photos
ABS,......................Best grip
Flexi at 85% infill ..2nd -being flexible they grab well
PLA ......................3rd, ok but tend to over tighten, which could break the scroll
NYLON..................3rd equal

Thanks to MrArrow1961 for the reverse jaws thingiverse.com/thing:624814

Check out this awesome assembly video https://vimeo.com/137431844
by yuri9999! http://www.thingiverse.com/make:155862

I have not included the Scad file at the moment, as it is a real mess,
if I can tidy it up I will post at a latter date-DONE
Thanks to Durwin Pye for cleaning the scad.