UPDATES!
5/14/17- Was notified that the brake is a bit too strong for some printers, Created two more versions. P1 Clearance is .1 more clearance and P2 clearance has .2 more. Comment if you would like to see more clearance than that.

Results

4/19/17- After the initial installation of this i aligned by X carriage perfectly horizontal by measuring with a digital caliper from the X rods to the Z axis stepper mounts.
Since then, the carriage has not changed one bit. I have not had to adjust my auto level sensor, and before this mod i had to adjust it every day.
This is the best mod i have ever done for my printer, and its super easy!

Just a tip!

After you install this, level your X carriage from the frame to the x axis rods, its very important that you level it to the rods, then make a mark on your stepper motor shaft collar and a mark on the Z-Brake with a sharpie, and you will never need to use the caliper again, and you can double check that they stay aligned by moving the Z axis up or down until the marks line up!

What Fer?

As soon as I printed other upgrade parts for my X axis carriage to line up the Z threaded rods I noticed that the entire carriage started to fall down when powered off, the weight of the X carriage was turning the Z axis rods very slowly overnight, and getting out of level. Anet must of intentionally
misaligned those rods to create some friction. If you have this issue too, here's a fix for you!

This will stop your Z Axis from falling down when your printer is off, but doesn't prevent your z-axis from moving, because your motors overpower it.

Install

if you have a squashed first layer make sure you clean that off of where it rubs on the shaft collar or else it will cause a LOT more drag than its intended to.

You might also run into an issue with too much drag, in this case the Z steppers will be unable to overcome this brake, you can either sand down the breaking surface, or adjust the potentiometer for your Z axis until your motors can overpower it, alternatively you can adjust the scaling or the included fusion 360 project to fit your printer or application.

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