02. Z-Axis Assembly

The following tools are required for this section of the guide:

Allen key / hex wrenches in the following sizes: 2.5mm, 3mm & 5mm

Avoid using ball end hex wrenches where possible as they are more prone to damaging the heads of smaller screws

The following are recommended for this guide:

Paper towels

Disposable gloves

A light oil, such as 3-in-1 or sewing machine oil

The linear rails are supplied with a protective oil coating on them. It is strongly recommended to prepare your work surface with paper towels and to wear disposable gloves

Paper Towels

Linear Rail

The oil on the rails protects them from rusting. You must either replace this oil after cleaning (as directed below), or make sure not to remove all of the original oil during preparation

An easy solution to both protect, and lubricate the rails, is using a light oil such as 3-in-1 or sewing machine oil

Apply a small amount of oil to a paper towel and then apply the oil to the rail by wiping it with the oiled paper towel. This may be done prior to, or after the installation of the linear rails

Do not remove the plastic stops installed in the ends of the linear rail at this point as they prevent the carriage from leaving the rail

More advanced users may wish to fully grease the rails & carriage with a specialised bearing lubricant. It is important to use the correct grade and make sure there are no additives such as PTFE, graphite, molybdenum disulfide, etc. The recommended grade of grease is EP00 or EP000 as these lubricate well, without being too viscous

With the linear rail still on the absorbent paper towels, carefully and slowly move the carriage from one end of the rail to the other

The carriage should move smoothly over the entire length of the rail

Small changes in resistance are normal, but the carriage becoming much harder to push, or binding completely are not

Repeat the previous test whilst applying a small amount of force downwards on the carriage

The carriage will likely travel more smoothly when applying a downwards force, this is normal

If the carriage does not move smoothly, or binds completely, refer to the Linear Rail Troubleshooting Guide

The SKUs for the V-Core 4.0 Z-axis linear rails vary depending on the size:

V-Core 4.0 - 300: 3x Linear Rail - HG15 400mm (SKU: HW3672GC)

Each rail has seven holes for mounting

V-Core 4.0 - 400: 3x Linear Rail - HG15 500mm (SKU: HW3416GC)

Each rail has eight holes for mounting

V-Core 4.0 - 500: 3x Linear Rail - HG15 600mm (SKU: HW3673GC)

Each rail has ten holes for mounting

M4x16 Cap Head Screw (SKU: HW3126SC)

T-Nut - Drop In Type for 30 Series - M4 (SKU: HW2774NC)

The required quantity of M4x16 Cap Head Screws and T-Nut - Drop In Type for 30 Series - M4 varies depending on size:

V-Core 4.0 - 300: 21 of each

V-Core 4.0 - 400: 24 of each

V-Core 4.0 - 500: 30 of each

2x align_3030_hg15 Printed Part (SKU: PP000005)

Please note: The alignment tools may have been printed in green or black. The design is the same regardless of colour

Prepared Z-axis linear rail from step 3

Remove both of the plastic stops in the linear rail

Make sure from this point onwards that the carriage does not leave the end of the linear rail

M4x16 Cap Head Screw

Insert an M4x16 Cap Head Screw into each mounting hole in the linear rail

T-Nut - Drop In Type for 30 Series - M4

Loosely thread a T-Nut onto each of the M4x16 Cap Head Screws. Do not tighten them at this point

Repeat the above instructions to assemble all three Z-axis linear rails

V-Core 4.0 Frame Assembly - Front-left corner

Prepared Z-axis linear rail assembly from the previous step

Align the Z-axis linear rail with the extrusion slot as shown

Make sure the small grease fitting is facing upwards

Make sure that all of the T-Nuts are slotted into the extrusion

Install the alignment tools, one near the top of the linear rail and the other near the bottom

Secure the linear rail to the frame assembly by tightening all of the M4x16 screws

Do not forget to tighten any M4x16 screws which are under the linear rail carriage

Remove both alignment tools

Move the carriage to the bottom of the linear rail

Repeat both the previous step, and this step to install the front-right Z-axis linear rail

Repeat both the previous step, and this step to install the rear Z-axis linear rail

3x NEMA17 Stepper Motor - 48mm (SKU: HW1078EC)

3x V-Core 4 Pillow Block - Nylon Injection Part (SKU: HW3848GC)

3x Coupler - Rigid Type - Black 25*20mm - 5mm to 8mm (SKU: HW2990GC)

3x Thrust Bearing F8-16M (SKU: HW2118WC)

12x M3x12 Cap Head Screw (SKU: HW1292SC)

It is recommended to lay the machine assembly on its back to make installation of the Z-axis stepper motors easier

NEMA17 Stepper Motor - 48mm

Install the stepper motor into the base plate as shown. The connector should face towards the back of the machine. Continue to support the stepper motor until it is secured later in this step

V-Core 4 Pillow Block - Nylon Injection Part

Place the V-Core 4 Pillow Block over the stepper motor shaft, aligning the four holes with the matching holes in the base plate

4x M3x12 Cap Head Screw

Insert each M3x12 Cap Head Screw through the Pillow Block, base plate, and thread them into the NEMA17 stepper motor. Once all 4 screws are threaded, fully tighten them to secure the assembly to the base plate

Thrust Bearing F8-16M - Please note: The thrust bearing has 3 components:

Install the thrust bearing into the Pillow Block as shown

2x End cap

Internal bearing race

It is recommended to add a drop or two of light oil (such as 3-in-1 or sewing machine oil) to the internal bearing race to lubricate it

Coupler - Rigid Type - Black 25*20mm - 5mm to 8mm

Install the coupler onto the stepper motor shaft

Whilst gently pressing the coupler downwards to compress the thrust bearing, fully tighten the marked M3 Cap Head Screw to secure the coupler to the stepper motor shaft

Repeat step 10 and step 11 to install the front-right Z-axis stepper motor

The front-right stepper motor connector should face towards the back of the machine

Repeat step 10 and step 11 to install the rear Z-axis stepper motor

The rear stepper motor connector should face towards the front of the machine

Stand the machine assembly back on its feet at this point, there should be no further need to access the underside until the wiring section of the guide

2x vc4_z_limit_right

1x vc4_z_limit_left

3x M6x12 Cap Head Screw

3x 3030 M6 Drop in T-Nut

Loosely thread the 3030 T-Nuts onto the M6x12 screws. Do not tighten them at this point.

Prepare the all 3 Z-axis limit assemblies

1x left z limit assemblies

2x right z limit assembly

vc4_z_limit_left assembly

Insert the 3030 T-nut on the side of the extrusion and slide it down, until the vc4_z_limit_left assembly is flush with the linear rail

Tighten the M6x12 Cap Head Screw to secure the assembly

Take care not to over-tighten the M6x12 screws as you can damage the printed parts

Repeat the previous steps and install the remaining vc4_z_limit_right assemblies

3x 48mm NEMA17 Stepper Motor

3x 375mm TR8x4 Lead Screws

3x Rigid Lead Screw Coupler

3x pillow_block printed part

More recent kits have this part injection molded, which is more accurate and easier to install.

12x M3x12 Cap Head Screw

3x Axial Thrust Bearing

pillow_block printed part

48mm NEMA17 Stepper Motor

Insert the NEMA17 motor into the base plate, as shown

M3x12 Cap Head Screw

Insert each M3x12 cap head screw through the pillow block, the base plate, and fasten them into the NEMA17 motor

Axial Thrust Bearing

The axial thrust bearing has three components. Two end caps and an inner bearing assembly.

Assemble the axial thrust bearing into the pillow_block as shown

Make sure that the thrust bearing is fully inserted into the printed part. The top ring of the thrust bearing should be flush with the top of the pillow_block.

If desired, you may add a drop of light oil to the inner bearing assembly of the thrust bearing

Install the lead screw coupler on to the exposed shaft of the NEMA17 motor. Use the smallest hole in the coupler for the stepper motor.

Apply downward pressure to the top of the lead screw coupler whilst tightening the marked screw

Tighten the marked M3 screw to secure the lead screw coupler to the motor shaft

375mm TR8x4 Lead Screw

Install the lead screw in the Rigid Lead Screw Coupler

Ensure the Lead Screw doesn't touch the NEMA17 motor shaft.

Tighten the M3 screw on the coupler, locking the lead screw.

Repeat the previous steps and install the other 2 lead screws

2x vc4_arm_front

2x M6x12 Cap Head Screw

2x Rat Rig Bi-Material Lead Screw Decoupler

2x TR8x4 POM Lead screw Nut

2x Rat Rig V-Core 4.0 - POM Arm Insert

8x M3x8 Cap Head Screw

4x M4x60 Cap Head Screw

4x M4x100 Cap Head Screw

Rat Rig Bi-Material Lead Screw Decoupler

TR8x4 POM Lead screw Nut

M3x8 Cap Head Screw

Front bed arm assembly

Lead screw decoupler assembly

M3x8 Cap Head Screw

Install a lead screw decoupler assembly into each arm as shown

Take care not to over tighten the M3x8 screws as you damage the printed parts

Rat Rig V-Core 4.0 - POM Arm Insert

Insert the POM arm insert, pay special attention to its orientation

Front arm assembly

M6x12 Cap Head Screw

Take care not to over tighten the M6x12 screws as you can damage the printed parts or the POM insert

M4x100 Cap Head Screw

M4x60 Cap Head Screw

Insert the screws through the front arm

Repeat Steps 12, 13 and 14 to assemble another front arm, NOTE: the POM insert must be rotated

NOTE: the POM insert must be rotated 45º compared to the previous assembly

Front arm assembly

The POM insert groove must be aligned as shown

Thread the Lead Screw into the front arm assembly

Do not force the Lead Screw through the POM nut on the decoupler as this can cause damage. It should thread through smoothly

Tighten the M4 Cap Head Screws to secure the arm to the carriage

Take care not to overtighten the M4 screws as you may damage the printed parts

Repeat the previous Step and install the Right front arm

The POM insert groove must be aligned as shown

2x M4x100 Cap Head Screw

2x M4x60 Cap Head Screw

1x vc4_arm_cable printed part

1x vc4_arm_rear assembly

1x TR8x4 POM Lead screw Nut

1x Rat Rig Bi-Material Lead Screw Decoupler

1x M6x12 Cap Head Screw

1x Rat Rig V-Core 4.0 - POM Arm Insert

6x M3x8 Cap Head Screws

Rat Rig Bi-Material Lead Screw Decoupler

TR8x4 POM Lead screw Nut

M3x8 Cap Head Screw

2x M3x8 Cap Head Screws

vc4_arm_rear printed part

Insert the M3x8 Cap Head Screws into the vc4_arm_cable printed part and tighten them into the rear arm heat inserts.

Take care not to overtighten the M3x8 screws as you can damage the printed parts

Lead screw decoupler assembly

M3x8 Cap Head Screw

Install a lead screw decoupler assembly into the rear arm as shown

Take care not to overtighten the M3x8 screws as you can damage the printed parts

Rat Rig V-Core 4.0 - POM Arm Insert

Insert the POM arm insert, pay special attention to its orientation

M6x12 Cap Head Screw

Take care not to over tighten the M6x12 screws as you can damage the printed parts or the POM insert

M4x100 Cap Head Screw

M4x60 Cap Head Screw

Insert the screws through the front arm

Rear arm assembly

The POM insert groove must be aligned as shown

Install the rear arm through the rear bed arm and decoupler

Thread the Lead screw in to the rear arm assembly

Do not force the lead screw through the POM nut on the decoupler as this can cause damage. It should thread through smoothly

Tighten the M4 Cap Head Screws to secure the arm to the carriage

Take care not to over tighten the M4 screws as you damage the printed parts

vc4_z_constraint_left

2x vc4_z_constraint_right

6x M6x12 Cap Head Screw

6x 3030 Drop-in T-Nut - M6

3x F688ZZ Ball Bearing

vc4_z_constraint

F688ZZ Ball Bearing

Insert the Bearing into the Z_constarin printed part

Make sure the bearing is inserted uniformly to avoid damaging the printed part - Use a flat surface like a wood table top to provide support to the printed part.

M6x12 Cap Head Screw

Insert an M6x12 cap head screw into each position on the lead screw constraint as shown

3030 Drop-in T-Nut - M6

Loosely thread a 3030 T-Nut onto each of the M6x12 screws. Do not tighten them at this point

Repeat the previous Step and assemble all the Z_constrains:

1x vc4_z_constraint_left assembly

2x vc4_z_constraint_right assembly

Left lead screw constraint assembly

Position the constraint assembly so that the left lead screw passes through the bearing

Rotate the constraint assembly anticlockwise and fit it to the rear 3030 extrusion as shown

Push the constraint assembly upwards until it touches the Z-axis limit printed part.

Fasten both M6x12 screws to secure the constraint assembly to the V-Core 4 frame

Take care not to over tighten the M6 screws as you damage the printed part

Right lead screw constraint assembly

Position the constraint assembly so that the right lead screw passes through the bearing

Rotate the constraint assembly clockwise and fit it to the rear 3030 extrusion as shown

Push the constraint assembly upwards until it touches the horizontal 3030 extrusion

Fasten both M6x12 screws to secure the constraint assembly to the V-Core 4 frame

Take care not to over tighten the M6 screws as you damage the printed part

Repeat the previous Steps and install the Rear Z constraint

The assembly should look like this.