UPDATE: 08-Nov-2016 Models rotated to align with buildplate. Scorchworks G-Code Ripper (Marlin Firmware-Frendly Version) added.

I designed this for use with my Mostly Printed CNC, which is an awesome design by Allted featured on Thingiverse http://www.thingiverse.com/thing:724999 and http://www.vicious1.com/. This 4th axis works well with laser and light cuts on wood with a router. Assembly views show how everything is put together. You can use my collet design or just attach a 3-jaw chuck like bobwombles design here on Thingiverse http://www.thingiverse.com/thing:624625. I've modified Scorchwork's awesome G-code ripper software to wrap rotary toolpaths on Marlin firmware based CNCs. I'll be posting the software on the Vicious 1 website soon. ROTATE MODELS TO SIT FLAT ON PRINT BED BEFORE PRINTING-I FORGOT TO DO THIS AND TOO LAZY NOW...

https://youtu.be/ihawzSSQpxg
https://youtu.be/ZUUMavkeaf8

Print settings and BOM shown below:

Prices based on PLA $22/KG
Collets - 15% infill - no support
3 inch - 39.85grams $0.88
2.5 inch 58.29grams $1.28
2 inch 75.82 grams $1.67
1.5inch 91.17grams $2.01
1 inch 103.94grams $2.29

Collet Body - 20% infill - no support
91.9 grams $2.02

Collet Nut-- 20% infill - no support
54.65grams $1.20

Headstock-25% infll- Use support for 90 degree overhang(stepper housing)
152.47 grams $3.35

Tailstock-25% infll-90 deg support buildplate only
124.3grams $2.73

Headstock BOM
(1) Nema17 stepper 84oz.in. recommended $13
(1) 4 pin xlr connector(optional) $2.50
(2) KFL000 10mm pillowblock bearings $3.60 / pair
(1) 25XL037 10mm bore aluminum timing belt pulley $6.33
(1) 5mm bore XL 10 tooth timing belt pulley $2.00
(1) 80XL037 80XL 40 tooth timing belt $4.00
(1) M10 x 1.25 x 100mm hex bolt $3.64
(1) M10 nut $0.50
(1) M10 washer $0.50
(4) M8 x 1.25 x 20mm hex bolt $0.50/ea
(4) M8 nuts $0.30 /ea
(4) M3 x 8-10mm socket head screws $0.12/ea

Tailstock BOM
(2) KFL000 10mm pillowblock bearings $3.60 / pair
(4) M8 x 1.25 x 20mm hex bolt $0.50/ea
(4) M8 nuts $0.30 /ea
(1) M10 nut $0.50
(1) M10 washer $0.50
(1) M10 x 1.25 x 90mm hex bolt $3.20