Specification Document Pathway:
A shipment of PP-MP0205 E3D Aero Steel Pinion Gears from PO# 31773 has a dimensional issue regarding the location of the set screw hole. Of 100 units checked only 14 were spec-conforming with 84 having a set screw location above the maximum spec tolerance of 2.75mm. The highest set screw hole location measured on these was 3.18mm. The difference between these units is shown on Picture 1, with the non-conforming gear on the left and the conforming gear on the right(correction made).
Checking how this could interact with the delrin gear, which aligns with the tooth on the opposing side from where the set screw location is (see picture 2), it appears that the 4mm wide delrin gear when aligned parallel with the pinion gear is sufficiently far from the set screw hole on the non-conforming units that there shouldn't be an issue. The gears that have a hole position of 3.18 have hole edges that are 4.66mm from the opposing side, while the gear itself is only 4mm. That leaves .66mm of extra space separating the delrin gear from the set screw hole, with full teeth interlocking(see Picture 2). If this is an accurate description of the interaction of these two parts(feedback needed), then I would suggest that the upper tolerance on the set-screw location be increased from 2.75mm to 3.25mm to reflect the limits of manufacturability.
I'll work with @jperry to inform E3D of the issue. I'll be holding these 2000 units in QC pending feedback on my findings. If we do need to reject them, having an estimated 84% fallout rate would be cause for a batch rejection.