Fully Parametric Screwdriver

NOTE: Development on Thingiverse has stopped. I will be continuing my development on Youmagine.

https://www.youmagine.com/designs/fully-parametric-screwdriver

The reason i am stopping development is Makerbot (the owner of thingiverse) has begun applying for patents for works done by the opensource printing community. This is theft of intellectual properties. I will leave this file up, but all future developments will be done elsewhere.
A screwdriver where you can simply adjust the bit size, body length, bit length, etc. It is intended to be printed, once i get a printer i will test it and post pics. Note: i double declared a variable, i have now removed it and uploaded the new file. It is my first scad models i would appreciate tips.