TAC 01 Ender 3 Z Axis Linear Rail Duel Motor and Rod

(This description and hardware list are a work in progress but nearly done. If you print it and have any issues, please comment on this listing to reach out!)

Description:
A 3d printed duel rod linear rail upgrade for ender 3 style 3d printers. FDM optimized for easy printing, durable, and part of the TAC-01 3D Printer ecosystem. All designs done in Tinkercad and fully editable.  Find Tinkercad links at homegrown3d.com 

Printing: 
All parts designed for 4x .4mm walls and 40% cubic infill. Should scale well with bigger nozzles. Prefer ABS, ASA, but reinforced nylon has worked well and PETG should work just fine too depending on how much heat you expose it to. I like making my designs thick so that even PLA might work but I don't like using PLA for functional parts. 

Assembly:
Install the x axis motor first. X axis untested with stock ender setup. See our Voron StealthBurner toolhead solution (coming soon). 

To mount the z axis rails: have the x axis motor mount attached and built. Then use 2 of the rail mounting tools to mount the z axis rails and attach and build their mounts. (install backlash nuts and rods last.) Once the z is attached to the x, use the rail mounting tools and move the x axis up and down on the rails smoothly and then secure it tighten. Make sure there is smooth action. do similar with lining up the z axis motors. Finally mount the backlash nuts and rods. once you have nice aligned smooth action, tighten down the z axis motor mounts and rods into the motor clamps. I will write a more thorough guide for the z axis motors when I rebuild a machine and remember how I did it. 

You will need a new wire harness or plan how to to wire your motors. 

I have both used a btt skrmini board with each z rod motor having their independent plug but a shared driver (individual drivers could be even better with how you tune it!), and also just split the wires and soldered them. It has worked amazing with well over 3000 print hours each on multiple machines.

To hold a consistent x axis tram (level) I will occasionally either bottom or top out the axis and then tram the bed to match that axis. Between the backlash nuts and these bed leveling clips, I barely ever have to level the bed or bottom/top out the x axis, generally only retramming after major printer maintenance. 

Hardware: 

I prefer this dimension of heat set insert 3mm x 5mm Lx 4.6mm OD

I like using Z axis backlash nuts, both pom and brass have worked well https://amzn.to/4k3kGoE

You will need m3 sliding t nuts to mount the z axis to the x axis extrusion  https://amzn.to/3LzYSUN

You will need m3 screws a bunch of m3 screws in the following estimated lengths and quantities. 

I finalized these designs and my machines a year ago and so this is a rough list drawn from my design files and not confirmed, and possibly not exact. I need to rebuild a machine and I will measure the screws then.

4x m3 45mm socket head. These mount the z axis to the X axis extrusion using t nuts 

8x m3 25mm socket head (these might be 30mm, im not sure) These mount to the z axis linear rails

12x m3 10mm socket head. 4 of these mount the Backlash nuts on the threaded z rod to the z axis. 4 mount the x axis motor to the x axis plate. 2 mount the wire management to the x axis plate using heat set inserts. 2 mount the wire management to heat inserts for the base piece. 

2x m3 8mm, these mount the x axis plate to the x axis with 2 t nuts 

1 x m3 20mm socket head. Mounts the x axis motor plate to the z axis heat set insert for stability

2 m3x6mm socket head, these mount the endstop switches to heat inserts

z rod motor screw sizes are TBD, and you also need a bunch of t nuts. will edit the guide with more details as I publish these full TAC-01 designs. 

 I like using 1/2 inch split wire loom for my wire management. https://amzn.to/3SqapsP 

These 4mm x 150mm (6 inch) zip ties have worked great https://amzn.to/4g38WCw

These wires have been nice, 24 gauge for most of the toolhead https://amzn.to/3SrRX2X  and 20 gauge for the hotend heater https://amzn.to/3Qmx88y 

You will need another z rod, z rod coupler, and motor. here are 2 350mm z rods, 300mm works as well but i prefer to have the extra 50mm https://amzn.to/4pXnXab

I also prefer to make sure the motors match and are the same, so might not hurt to get a new set of motors.

MGN H Rails