Dual Z Screw upgrade Guide for the Mega Zero v1.0

Ladies and Gents, This is myDual Z Screw upgrade for the Mega Zero v1.0.

UPDATED: 29th March 2021

I have replaced only some of the OEM parts and tried to make sure critical parts are identical - here are the parts I'mcurrently using:

Printed Parts:

Printed 2nd Z-screw mount and Spacers x1:
https://www.thingiverse.com/thing:4804383

X-Gantry Crash leveler x2:
https://www.thingiverse.com/thing:4808777

Purchased Parts:

8mm pitch Lead Screw with Anti-backlash Nut x2:
https://www.bilby3d.com.au/DispProd.asp?CatID=&SubCatID=106&ProdID=ptRodLead8x400

NOTE: 400mm tall Z-screws will hit your filament roll - I used T-nuts to move the holder to the center of the frame. 350mm is a better length if you can find good quality units with Anti-backlash Nuts. The units I used come with 4mm, non-threaded holes on the mount. You can either use M3 bolts + nuts or just tap them to use M4 bolts (which is what I did).
https://cdn.thingiverse.com/assets/5b/86/24/a0/97/2021-03-29\_14.04.45.jpg

Adjustable Metal Z-Axis T8 Lead Screw stabilizers x2:
https://www.amazon.com/gp/product/B08T9PL29W/ref=ppx\_yo\_dt\_b\_asin\_title\_o00\_s00?ie=UTF8&psc=1

NEMA 17 Stepper Motor x2:
https://www.amazon.com.au/gp/product/B06XSYP24P/ref=ppx\_yo\_dt\_b\_asin\_title\_o02\_s00?ie=UTF8&psc=1

Aluminum NEMA 17 Stepper Mount x1:
https://www.aliexpress.com/item/4001205490125.html?spm=a2g0s.9042311.0.0.51b34c4d6ySBzN

5mm to 8mm Bore Flexible Couplers x2:
https://www.amazon.com.au/gp/product/B083LD6Y5P/ref=ppx\_yo\_dt\_b\_asin\_title\_o02\_s00?ie=UTF8&psc=1

Dual Z-Axis Stepper Wiring adapter x1 (only required for stock MZ1 Mainboard):
I made my own using proto-board but you can buy a Y-cable for this.
https://www.amazon.com.au/yotijar-Stepper-Motor-Cable-Duale/dp/B08D3XK4BR/ref=sr\_1\_1?dchild=1&keywords=stepper+motor+dual+cable&qid=1615243515&sr=8-1

Installation process for the second Z-screw:

1/ Move the Z gantry up to about 180mm on the Z-axis
2/ Install the 2nd Z-Stepper motor - then attach the coupling to the stepper shaft and tighten it - leave a couple of mm between the top of the shaft and the landing for the Z-screw so they don't touch
3/ Install the z-screw into the coupling and tighten it
4/ install the screws mounting the z-screw Nut but leave them loose so it can move around
5/ Install your adjustable top z-screw shaft stabiliser onto the frame - ensure the shaft is straight (X-axis) before tightening the mounts. don't tighten Y-axis bolts yet.
6/ use the depth gauge on your digital calipers to measure the distance from the screw to the frame (Y-axis) just above the coupler.
7/ use that measurement to position the z-screw on the Y-axis in the top stabiliser and then tighten the bolts
8/ now that your z-screw is installed parallel to the frame, tighten the z-screw mount bolts attaching it to the X-gantry

I'm using Nulon Extreme Performance Grease with PTFE to lubricate the Y-axis rails and the Z-screws:
https://www.ebay.com.au/itm/Nulon-Extreme-Performance-Grease-with-PTFE-450g/313190833415?ssPageName=STRK%3AMEBIDX%3AIT&\_trksid=p2057872.m2749.l2648

Now just enjoy results like this!
https://cdn.thingiverse.com/assets/0d/1c/06/b3/ab/2021-03-29\_15.37.08.jpg

Print Settings

Printer:

Anycubic Mega Zero

Rafts:

No

Supports:

No

Resolution:

0.2

Infill:

25% Cubic

Filament: X3D Pro PLA

Category: 3D Printers