Instructions

Included in the zip file are:
.par =Solid Edge
.stp
.igs
.stl
For detailed instructions see:
vinland.com/UM_Extruder_Bearing.html

The bearing can be found here for $7.41:
mcmaster.com/#standard-ball-and-roller-bearings/=i853dw
It is a Dynaroll SMR128ZZ A5

The spring OD is 7.72mm, has 8 turns of 1.14mm wire, and a free length of 20.9mm. Sorry, I do not have any part number since it came from my big junk box...

Since I needed to measure the spring used for the Ultimaker Upgrade I documented the steps both for a high accuracy measurement procedure and a simplified one.

vinland.com/Spring-Testing.html

Note, the spring for the upgrade is not critical. There is a tremendous adjustment range.

I added a section on Extruder Drive Force Measurements:
vinland.com/Extruder_Drive_Force.html

The long screw is 50mm.
The shaft screw needs to be 20mm since the yoke is 18mm.

            </div>
        </div>