Summary

2 improvements:

1) I changed the position of the spring bump up 2mm to increase spring tension when using the springs from the standard makerbot replicator 2 upgrade kit available from makerbot.

2) I had trouble getting proper clearance between this drive block and the base piece and my wires running to my nozzle heaters. I shorted the block 2.5mm on the underside and have had good results. Thought I'd share for those having a similar problem.

Update: Added .STP files for original piece (recreated) that does have the additional spring tension update, but not the shortened base. Also added .STP for the new version.