Mk8 Spring loaded Drive Block Replicator 1 / Duplicator 4 / FlashForge / CTC

Adapted version of ivcs fillament drive block: http://www.thingiverse.com/thing:62510

Update: DriveBlockBase V9 allows printing of NinjaFlex and other flex filament and is tested on WanHao Duplicator 4 and CTC Dual with NinjaFlex. Please see attached pictures and read instructions for some tips how to configure your slicer right to not blame the drive block for mistakes you make.

Original idea was to modify it that it can handle bigger draw rolls, like used on Wanhao Duplicator 4, which has a 11mm cylindric gear-wheel with and a 12mm ball bearing draw roll with a grooved surface and a shaft diameter of 3mm.
I read a lot of broken ball bearing shafts and because 3mm is a very weak shaft diameter if you use a strong spring I decided to add a M3 pan head screw as shaft instead. In addition all spring loaded drive blocks I know have overhanging ejection units on the outer sides. I think this might disturb some ideas to use the extra head room we have in the printer especially to the left to install a bigger heated build plate. On top of the extruders here we have some space left, which I decided to use for the ejection buttons.

I had several stages of development of this unit but I run my current version since 6 months now, without any issues and decided to release it now as stable.

Of course this mod should also work with the Original Replicator and 623ZZ ball bearings ivc recommends.

See instructions tab for information how to print and what extra parts you need.