04. Z-Axis Assembly

1x T-Slot extrusion 40120 - 250mm

3x M12x25 Countersink screws

3x M12 Washer

3x M12x25 Cap Head Screw

Rat Rig StrongHold ONE CNC - Z-Axis Bottom 10mm

Rat Rig StrongHold ONE CNC - Z-Axis Top 10mm

T-Slot extrusion 40120 - 502mm

Rat Rig StrongHold ONE CNC - Z-Axis Bottom 10mm

3x M12x25 Countersink screws

Both plates must be facing upwards.

Rat Rig StrongHold ONE CNC - Z-Axis Top 10mm

3x M12 Washer

3x M12x25 Cap Head Screw

2x Linear Rail - MGN15 250mm + 2 x MGN15C carriage

12x M3x16 Cap Head screws

12x 4040 Drop-in T-Nut - M3

2x align_40120_mgn15 printed part

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

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

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

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

The linear rail carriages are not interchangeable. Do not try to use a carriage on a different linear rail than the one it was supplied with.

Check this guide if one or more carriages don't move smoothly.

Do not allow the linear rail carriages to leave the end of the rail at any point

MGN15 Linear Rail

Insert an M3x16 cap head screw in each of the holes on the linear rail

Loosely thread a 4040 T-Nut on to each of the M3x16 screws

Repeat these instructions for the second linear rail

Place one Z linear rail assembly on the designated T-slot.

Insert the two align_40120_mgn15 printed jigs in the T-Slot and rail.

Make sure the align_40120_mgn15 printed jigs are correctly placed and centering the rail on the T-slot

Tighten the linear rails screws one at a time starting from the front and making your way towards the back, one by one.

MGN15 Rails should be tightened to 98 N-cm of torque, overtightening the screws will result in rail binding.

Rat Rig Mill - Z Plate

4x M5x16 Low Head Screw

4x M5 Nylon Locking Hex Nuts

2x Nut Block for TR8x4

16x M3x6 Cap Head Screws

Nut Block for TR8x8

M5 Nylon Locking Hex Nut

Insert the M5 Locking Hex Nuts in to the Nut Block

Prepare two assemblies.

Rat Rig Mill - Z Plate

Nut Block for TR8x4 assembly from the last step.

The M5 Nylon Locking Hex Nuts, must be facing away from the Y gantry plate.

Gently tighten the M5x16 Low Head Screws on the designated holes.

Do not overtighten the screws as it will cause binding in the lead screw. Tighten until the nut block is flush with the plate and add half a turn on the screws.

Thread the M5x16 Low Head Screws on the designated slot, Do not tighten this Nut Block, it will be adjusted later.

Place the second Z linear rail assembly on the T-slot but DO NOT tighten the screws.

Install the Z Joiner assembly on the linear rails.

Ensure the M5 screw slots are facing the Rat Rig StrongHold ONE CNC - Z-Axis Bottom 10mm side as shown.

Using the 16x M3x6 Cap Head screws, fasten the XY joiner plate assembly to the mgn15 carriages.

MGN15 Rails should be tightened to 98 N-cm of torque, overtightening the screws will result in rail binding.

Tip: Blue thread lock can be added to the thread of the M3x6 Cap Head screws.

While the second linear rail remains loose, the Z plate should move smoothly without resistance. If you experience any binding or drag, slightly loosen the carriage screws, as they may be overtightened.

Be careful to ensure that the Z joiner plate carriages do not detach from the linear rail during the process.

Move the Z joiner fully to the front as demonstrated. Then, gradually move it toward the back, exposing one linear rail screw at a time, and tighten each screw as you progress.

Ensure that all linear rail screws are tightened from front to back. Avoid overtightening, as this may cause binding and restrict movement.

MGN15 Rails should be tightened to 98 N-cm of torque, overtightening the screws will result in rail binding.

Leadscrew - TR8x4 Metric - 281mm

2x Ball Bearing 688ZZ

2x Shim - 12 x 8 x 1mm

2x Lock Collar

Thrust Bearing F8-16M

Coupler - Disc Type

688ZZ Ball bearing

Push the ball bearing against the inner side of the plate, ensuring it stays inside the designated groove.

Push the Lead Screw through the hole in the ball bearing

Thrust Bearing F8-16M

Install the Thrust Bearing on to the exposed end of the Lead Screw as shown

Lock Collar

The Precision Shim 12x8x1mm should be in between the 688ZZ Ball bearing and the Lock Collar

Screw the Lead Screw through both Nut Blocks under the Y joiner plate.

Lock Collar

Slide the Lock Collar on to the Lead Screw

Precision Shim 12x8x1mm

Slide the Precision Shim on to the Lead Screw

Ensure the lead screw surface is roughly 1-2mm inside the plate.

Tighten the set screw on the lock collar to secure it in place.

Precision Shim 12x8x1mm

Slide the Precision Shim on to the Lead Screw

Coupler - Disk Type

Install the Coupler on to the exposed end of the Lead Screw.

Push the coupler against the metal plate and tighten the set screw.

Push the lock collar against the axial bearing to ensure the axial bearing is making full contact with both surfaces.

Tighten the set screw on the lock collar.

Nema 23 Stepper Motor High Torque

4x 40mm Aluminium Spacer

4x M5x50 Cap Head Screw

mill_stepper_cable_management printed part

4x 40mm Aluminium Spacer

Nema 23 Stepper Motor High Torque

4x M5x50 Cap Head Screw

Tighten the set screw on the coupler, to secure the stepper motor shaft to it.

Insert the mill_stepper_cable_management printed part as shown.

4x M8x25 Cap Head Screw

4x M8 Nylon Locking Hex Nut

8x M8 Washer

Place the Z-axis assembly on the Z tower, ensuring the M8 Low Head

The Z-axis is heavy and difficult to manage alone. Please request assistance from another person to hold the Z-axis while you tighten the screws.

Assemble the M8x25 cap head screws by inserting them through the M8 washers and the Z plates. Then, place an M8 washer on the rear and secure everything with an M8 nylon locking nut.

4x M8x25 Cap Head Screw

8x M8 Washer

4x M8 Nylon Locking Hex Nut

4x M6x8 Set screws

Look through the threaded holes; there should be no light visible on the other side. If you see light, it indicates that one of the Z plates is installed upside down. Visit this 02. Z Tower Assembly and flip the Z plate upside down.

Lightly thread the set screws into the designated holes. Once they reach the rear Z plate, stop tightening.

These screws are intended to assist the user in tramming the spindle during the commissioning process.