3D printing bugs bitten me few months back..I was waiting for decrease in price of ABS 1.75mm filament but still it has 30US dollar/ Kg.. So before investing on 3D printer electronics i first ordered parts for my DIY filament extruder... Following are some details...

Few close up pictures:
1- Nozzle hole diameter = 1.6mm, I think it will give me 1.7mm.
2- used Car wiper motor
3-One gear box laying around in backyard (1:60 ratio)
4- Auger bit was purchased from China at 12US dollar
5- Low cost Chinese PID temperature controller with K type thermocouple.
6- Some insulation etc.

Here is the dismantle version of the filament extruder. In the center you can see a bolted flange. The white gasket is thermal isolator between hotend and the augur bit cylinder.I tested the setup without the thermal isolator flange and it worked well, however, the heat traveled toward the auger bit and when i shutdown the unit it was difficult to restart the system as the melted ABS melted and jammed the bit.
I dismantled and provided a thermal barrier between the hotend and the auger bit.
I extruded the filament of size 1.75mm +-0.2mm. I just increased the hole diameter of the nozzle from 1.68mm to 1.7 mm and i shall soon check the end results ..
Here is the link of the video of 1st trial test extruding 1.7mm ABS at 200 Celsius...
https://www.dropbox.com/s/b8ultovzcw...20extruder.wmv