fuck i can't wait to prove you wrong when i finish mine. granted i've spent hours solely in engineering it, and i have better engineering skills/resources then a lot of people on here (not trying to sound cocky)
heres a screencap of the head
(click for big)
it's clear polypropylene and steel in the plans, but i switched to black abs. granted, itl end up costing a hundo or so, but if i can diy it, i will, regardless of cost. as long as its not way over the actual product cost. thats just how i work. also i have access to a cnc and 3d printer for whatever i want.