A couple of people have mentioned some interest in the Micrometer based endstop target modification I have on my printer. I designed that one into my Z openbuilds retrofit parts, but until now, there wasn’t a standard Taz 4/5 variant. That has now changed however.
Basically, the issue with the stock bolt and spring endstop target is that it can move with repeated impacts and heat and cooling cycles. Every time the limit switch hits it, it releases pressure on the threads, which allows the spring to sometimes press the bolt upwards a tiny fraction of a mm. Eventually, after a few hundred impacts, the bolt moves up far enough to screw with your layer height.
By replacing it with a micrometer, you get an endstop target that will never move due to heat or impact, and allows repeatable layer height adjustments to the thousandth of an inch.
I used this Micrometer here: http://www.ebay.com/itm/Precision-Micrometer-Head-/160677507469?hash=item256920318d which seems to be a knock of Mitutoyo of some sort.
You can see the micrometer in the picture below on the Endstop target left side of the Taz.
Taz_4_5_Z_Motor_Micrometer_2_1_a.stl (382 KB)