Triple Motor Z-axis Tilt, Ender 7 Z-axis Kinematic Bed Mount Upgrade

Update 01.04.24. Stepper Motor Brackets Revised, now Rev2 (to prevent cracking)

Update 04.02.24. Step files uploaded.

This is my Triple Motor Z Axis Tilt project, for the Ender 7.

This Z tilt setup is a little bit different from the norm with belt drive instead of lead-screws. It uses geared stepper motors to get the required step resolution, 0.02mm per full step, and it can hold the weight of the bed plus1.5kg on top when the motors are turned off. The geared 28mm square body steppers have a 20:1 ratio and are the same ones used on a SecKit Cube printer. https://www.aliexpress.us/item/1005003837995982.html

The bed mounting is Kinematic and uses parts from the RatRig printer. I couldn't mount the rear centre ball directly to the bed as the heating element is there, so I made a aluminium strip bracket to hold the ball in place. At the front I opened up the front clip corner holes to 5mm dia & countersink them to use the M5 countersunk screws. 

Modifications to the frame are to rotate the rear C section extrusion 180 degrees to provide a more suitable mounting face for the top pulley block and liner rail, and the front pillar extrusion have been moved forward 70mm, to line them up with the front of the bed. 

The standard Ender 7main control board is unsuitable for this project, as it only has 4 stepper drivers on it. With the triple motor Z you need an extra 2 stepper drivers. I had already upgraded my board to a BTT Manta E3EZ which had 5 stepper drivers, so I added a CanBus BigTreeTech MMC extension board to give us 4 more drivers. There are many other control boards to choose from to make this work, it doesn't have to be the same as this setup. Unfortunately this part of the project makes it an expensive one.

Cost. Budget on £200 for the Z-axis parts, plus £130 for the computer & stepper driver upgrade.

Below parts list may not be complete. Updates may follow.

Parts to print:

1 off Triple Z-axis Tilt Arm LHS

1 off Triple Z-axis Tilt Arm RHS

1 off Triple Z-axis Tilt Arm Rear

1 off Triple Z-axis Tilt Motor Mount LHS

1 off Triple Z-axis Tilt Motor Mount RHS 

1 off Triple Z-axis Tilt Motor Mount Rear

2 off Triple Z-axis Tilt Top Pulley Block Sides

1 off Triple Z-axis Tilt Top Pulley Block Rear

3 off Belt Tensioner Belt Pulling Blocks

3 off Belt Tensioner Top Cap Clamp

9 off Spine Cable Cover Segments

2 off Front Frame Leg Nut Holders

1 off Front Frame Leg Bottom Mount Drilling Jig

1 off Front Frame Leg Top Mount Drilling & Tapping Jig

1 off Bed Rear Ball Bracket Drilling Jig

1 off BTT MMC control board mounting bracket – optional.

Parts to purchase:

3 off 400mm MGN12 Liner Rails.

3 off MGN12C Compact Carriage Blocks.

3 off Toothed Idler Pulley 3mm bore 20T for 10mm wide GT2 belt (14mm overall wide)

3 off Drive Pulley 6mm bore 20T for 10mm wide GT2 belt 

3 metre 9mm wide Gates GT2 Belt

3 off Sumtor Nema 11 28mm square x 33mm long Stepper Motor with 20:1 reduction gearbox. Part number: 28HS3306A4-XG20. https://www.aliexpress.us/item/1005003837995982.html

1 off Piece of Aluminium 5mm thick x 15mm x 183mm (15x5mm extrusion)

6 off Stainless Steel Dowel Pins 35mm long x 3mm diameter.

3 off Magnets 20 x 10 x 5mm - Two hole (for M3 Countersunk screws) 

3 off 12mm dia. Mild Steel Zinc Plated Balls with M5 threaded hole. Not stainless steel. 

2 off Anodised Aluminium Standoff Spacers 5mm inside diameter (M5) x 6mm long.

3 off M12 Cable Glands

1 meter Expandable Braided Cable Sleeving

Heat-shrink

3 off XH2.54 4pin connector & crimp terminals

1 off Main Control Board Upgrade. At least 6 stepper motor drivers required. Must be able to run Klipper. 

Fasteners & Misc:

Liner Rails

27 off M3 Drop In Tee T Nuts for 2020 Profile Extrusion V-Slot

27 off M3 x 8mm long Hex Socket Cap Head Screws

Triple Z-axis Tilt Arms

12 off M3 x 10mm long Hex Socket Cap Head Screws (for the carriage blocks)

6 off M3 x 25mm long Hex Socket Cap Head Screws (for the belt clamp)

3 off M3 x 30mm long Hex Socket Cap Head Screws (for the tensioner)

6 off M3 x 12mm long Hex Socket Countersunk Head Screws (for magnet)

15 off M3 Hex Nuts (for magnet & belt clamp/tensioner)

21 off M3 Washers (for the carriage block screws & belt clamp/tensioner)

Triple Z-axis Tilt Motor Mounts

12 off M3 x 12mm long Hex Socket Cap Head Screws

6 off M3 x 25mm long Hex Socket Cap Head Screws

18 off M3 Washers

12 off M3 Drop In Tee T Nuts for 2020 Profile Extrusion V-Slot

6 off M3 Hex Nuts

Triple Z-axis Tilt Top Pulley Block Sides

8 off M3 x 10mm long Hex Socket Cap Head Screws

2 off M3 x 30mm long Hex Socket Cap Head Screws

8 off M3 Washers

8 off M3 Drop In Tee T Nuts for 2020 Profile Extrusion V-Slot

2 off M3 Hex Nut

Triple Z-axis Tilt Top Pulley Block Rear

2 off M3 x 10mm long Hex Socket Cap Head Screws

2 off M3 x 20mm long Hex Socket Cap Head Screws

1 off M3 x 30mm long Hex Socket Cap Head Screws

4 off M3 Washers

4 off M3 Drop In Tee T Nuts for 2020 Profile Extrusion V-Slot

1 off M3 Hex Nut

Printing Bed

2 off M5 x 16mm long Hex Socket Countersunk Head Screws 

1 off M5 x 10mm long Hex Socket Countersunk Head Screws 

2 off M3 x 16mm long Hex Socket Countersunk Head Screws 

Tools Required:

Vertical Drill Press

Battery Drill

5mm diameter drill bit

3mm diameter drill bit

4.2mm diameter drill bit

M5 thread cutting tap

M3 thread cutting tap

45 degree countersink cutter

12mm diameter drill or hole saw.

Engineer PA-09 Crimp Tool.

Headband Magnifying Glasses.