With the High Z Modification for the LEAD CNC, the Z-Travel is increased to approximately 200mm! This modification revolutionises the work-pieces the LEAD CNC Machine is capable of.

The High Z Mod uses dual extrusions for the X-Axis and connected gantry carts to increase the strength and stability while decreasing flex across the X-Z Axis.

Designed to be easily adapted to an existing LEAD CNC build, the High Z Mod is an elegant and structural solution to the age-old problem with Z-Height restrictions.

The Maker Store High Z Mod is based on the original design published by OpenBuilds, however there are some small differences.

Please note that while we have spent a considerable amount of time and effort putting these instructions together, any errors and omissions excepted (E&OE). If you find an error or have a suggestion on how to make this manual better/clearer or etc, please let us know so we can continually improve this resource.

These assembly instructions are for the following machines:

• Lead CNC Machine – 1000 x 1000
• Lead CNC Machine – 1500 x 1000
• Lead CNC Machine – 1500 x 1500
• Lead CNC Machine– High Z Mod – 1000 x 1000
• Lead CNC Machine– High Z Mod – 1500 x 1000
• Lead CNC Machine– High Z Mod – 1500 x 1500

Before starting any build, it is a good practice to get organised. Start by unpacking all parts received and checking each part off against the Bill of Materials at the bottom of this assembly guide. If you find any parts missing please contact us as soon as possible.

You will need the following tools:

• 3mm Allen Key
• 8mm Spanner
• 10mm Spanner
• Screw Drivers
• M5 Tap
• Builder‘s or Machine Square
• Lead Screw Tensioning Tool

We recommend that you read through the whole assembly guide before beginning the build, as this enables you to get a rough idea of how it all goes together. Before starting each step make sure you have studied the drawing and fully understand the instructions.
When attaching parts, if a part is requiring significant force to attache, stop, take it off, re-read the instructions and try again. Do not over tighten screws as you may strip the thread or head.
If you have any questions regarding the build please contact us at sales@makerstore.com.au, we are happy to help!

Step 1 Assemble the Solid V Xtreme Wheel as per the drawing. Ensure you only use 1 Precision Shim between the two 6252RS Bearings

Step 2 Repeat this for 27 Solid V Xtreme Wheels

Step 1 Attach 2x ACME-Nut-Block to one of the C-Beam Gantry Plate XL's using M5 Low Profile 25mm & M5 Nylon Nuts. On each screw, in between the ACME Nut Block and the Gantry Plate XL, there should be a 3mm Metric Aluminium Spacer. Only loosely tighten these screws so the ACME- Nut Blocks can still move side to side.

Step 2 In each corner of the gantry plate you attached the ACME Nut Block's too, insert a 60mm M5 Low Profile Screw.

Step 3 For the larger holes that you have inserted a 60mm M5 Low Profile Screw use a 6mm Eccentric Spacer. This will sit inside the hole.

Step 4 In this order on the screws with 6mm Eccentric Spacers add a Solid V Xtreme Wheel, 9mm Metric Aluminium Spacer, another Solid V Xtreme Wheel, and then another 6mm Eccentric Spacer facing the opposite way to the first spacer.

Step 5 For the leftover screws place a 6mm Metric Aluminium Spacer, Solid V Xtreme Wheel,9mm Metric Aluminium Spacer, Solid V Xtreme Wheel and a 6mm Metric Aluminium Spacer.

Step 6 Add the extra C-Beam Gantry Plate XL and use M5-Nylon-Nuts to clamp it all together.

Step 7 Repeat the above steps 1-6 more time to make another Gantry.

Step 1 Attach 4x 90 Degree Angle Corner Connectors using 10mm M5 Low Profile Screws. Attach these to the gantry plate that has the 8mm Acme Nut Block's.

Step 2 On each of the 90 Degree Angle Corner Connector's, attach a Tee Nut using an 8mm M5 Low Profile Screw.

Step 3 Slide the V-Slot 2080 250mm between the 90 Degree Angle Corner Connector's and use the Tee nuts to lock the V-slot into place, the V-Slot should be flush with the bottom of the C-Beam Gantry Assembly

Note In the later steps when you attach the Gantry Assemblies the Eccentric Nuts should be on the Bottom set of wheels, not the Top.

Step 1 Roll the Y-Axis Gantry onto the C-Beam. Insert the Lead Screw and “screw” it into the 2 x 8mm Acme Nut Block. Adjust and tighten the 2 x 8mm Acme Nut Block so that the Lead Screw can turn easily with no backlash.

Step 2 Adjust and tighten the Eccentric Spacers so the gantry rolls smoothly and without “wobble”.

Step 3 Insert 2x Tee Nuts into each of the bottom channels of the C-Beam.

Step 4 Attach an 8mm Lock Collar to the Lead Screw then a 688Z Bearing.

Step 5 Using the 4x 20mm M5 Low Profile Screws, attach the C-Beam End Mount.

Step 6 Attach the Thrust bearing to the Lead Screw then an 8mm Lock Collar, leave the Lock collars loose, these will be tightened later.

Step 7 Attach the 2040 End Cap using 8mm M5 Low Profile Screws as per the below picture.

Step 8 Repeat Steps 1-7 to make the A-Axis (second Y-axis).

Note that the Y-Axis and A-Axis should be mirror images of each other.

Step 1 Attach an 8mm Lock Collar to the Lead Screw followed by a 688Z Bearing.

Step 2 Using the 20mm M5 Low Profile Screws, attach the C-Beam End Mount.

Step 3 Attach a Thrust bearing to the Lead Screw followed by an 8mm Lock Collar and the 635x8mm Flexible Coupling. Leave the Lock collar and the Flexible Coupling loose.

Step 4 Attach the motor using 40mm and 6mm Spacers with 60mm M5 Low Profile Screw's. Adjust the Lead Screw so that the Lead screw and the Motor shaft are almost touching. Move the 635x8mm Flexible Coupling so that it sits centre over the gap between the Lead screw and the Motor shaft and fix the coupling into place. Tighten the Lock collar closest to the Motor only and ensure that the thrust bearing is held firmly against the C-beam End mount.

Step 5 Repeat Steps 1-4 for the A-Axis

Step 1 Attach the Anti-Backlash Nut Block to one of the C-Beam Gantry Plate XL's using 2x M5-Low-Profile-20mm & 2x M5-Nylon-Nuts. On each screw, in between the ACME Nut Block and the Gantry Plate XL, there should be a 3mm Metric Aluminium Spacer. Tighten the screws so the Anti-Backlash Nut Block is secured.

Step 2 Insert a 30mm M5 Low Profile Screw in each corner of the gantry plate. For the screws with the larger holes use a 6mm Eccentric Spacer this will sit inside the hole. Add a Solid V Xtreme Wheel and a 5mm Nylon Lock Nut. Repeat this step once for the other large opening.

Step 3 For the leftover screws place a 6mm Metric Aluminium Spacer, Solid V Xtreme Wheel and a 5mm Nylon Lock Nut.

Note Before inserting lead screw please ensure the set screw in the Anti-Backlash Nut Block is not tensioned.

Step 1 Insert the lead screw and “screw” it into Anti-Backlash Nut Block. Adjust the set screw so that the lead screw is still easy to turn but there is extra resistance. Roll the Z-Axis Gantry onto the C-Beam. Adjust and tighten the Eccentric Spacers so the gantry rolls smoothly and without “wobble”.

Step 2 Attach an 8mm Lock Collar to the Lead Screw then a 688Z Bearing. leave the Lock collar loose

Step 3 Using 20mm M5 Low Profile Screws attach the C-Beam End Mount.

Step 1 Attach an 8mm Lock Collar to the Lead Screw then a 688Z Bearing. leave the Lock collar loose

Step 2 Using the 20mm M5 Low Profile Screws, attach the C-Beam End Mount.

Step 3 Attach the 635x8mm Flexible Coupling, leave the Lock collar and the Flexible Coupling loose.

Step 4 Attach the motor using the 40mm Spacers with the 55mm M5 Low Profile Screws. Adjust the Lead Screw so that the Lead screw and the Motor shaft are almost touching. Move the 635x8mm Flexible Coupling so that it sits centre over the gap between the Lead screw and the Motor shaft and fix the coupling into place. Tighten the Lock collars so that both the 688Z Bearings are secured in the recesses.

Step 1 Attach 2x ACME-Nut-Block to one of the C-Beam Gantry Plate XL's using M5-Low-Profile-25mm & M5-Nylon-Nuts. On each screw, in between the ACME Nut Block and the Gantry Plate XL, there should be a 3mm Metric Aluminium Spacer. Only loosely tighten these screws so the ACME- Nut Blocks can still move side to side.

Step 2 place a 60mm M5 Low Profile Screw in each corner of the gantry plate you attached the ACME Nut Block's too. For the screws with the larger holes use a 6mm Eccentric Spacer this will sit inside the hole, then add a Solid V Xtreme Wheel, 9mm Metric Aluminium Spacer, another Solid V Xtreme Wheel, and then another 6mm Eccentric Spacer facing the opposite way to the first spacer. Repeat this step once for the other large opening.

Step 3 For the leftover screws place a 6mm Metric Aluminium Spacer, Solid V Xtreme Wheel,9mm Metric Aluminium Spacer, Solid V Xtreme Wheel and a 6mm Metric Aluminium Spacer.

Step 4 Add the extra C-Beam Gantry Plate XL and use M5-Nylon-Nuts to clamp it all together.

Attach the X-Axis Gantry Assembly to the Z-Axis Actuator Assembly using 10mm M5 Low Profile Screw. The Eccentric nuts on the X-Axis Gantry Assembly should be on the opposite side to the Z-Axis Actuator Assembly Motor, see the below images for your reference.

Roll the X-Axis - Z-Axis Assembly onto the C-Beam. Insert the Lead Screw and “screw” it into the gantry. Adjust and tighten the 2 x 8mm Acme Nut Block so that the Lead Screw can turn easily with no backlash. Adjust and tighten the Eccentric Spacers so the gantry rolls smoothly and without “wobble”.

Step 1 Insert 6x Tee nuts in the Top rear Channel, insert 2x Tee Nuts in each of the back Slots and insert 2x Tee nuts in the bottom rear Channel. These will be used later for the to attach the X-Axis to the Y-Axis.

Step 2 Attach an 8mm Lock Collar to the Lead Screw followed by a 688Z Bearing.

Step 3 Using the 20mm M5 Low Profile Screws, attach the C-Beam End Mount.

Step 4 Attach the Thrust bearing to the Lead Screw then an 8mm Lock Collar, leave the Lock collars loose, these will be tightened later.

Step 1 Attach an 8mm Lock Collar to the Lead Screw followed by a 688Z Bearing.

Step 2 Using the 20mm M5 Low Profile Screws, attach the C-Beam End Mount.

Step 3 Attach the Thrust bearing to the Lead Screw then an 8mm Lock Collar and the 635x8mm Flexible Coupling, leave the Lock collar and the Flexible Coupling loose.

Step 4 Attach the motor using the 40mm and 6mm Spacers with 60mm M5 Low Profile Screw's. Adjust the Lead Screw so that the Lead screw and the Motor shaft are almost touching. Move the 635x8mm Flexible Coupling so that it sits centre over the gap between the Lead screw and the Motor shaft and fix the coupling into place. Tighten the Lock collar closest to the Motor only and ensure that the thrust bearing is firmly held in place.

Step 1 Attach the X-Axis Assembly using 90 Degree Corner Brackets to the inside of the 250mm 2080 extrusion as shown below.

Step 2 Attach a 90 Degree Corner Bracket to the underneath C-beam and the end of the 250mm 2080 extrusion as shown below. Repeat this step of the A-Axis

Step 3 Attach a Plate 90-5 to the X and Y axis using 8mm M5 Low Profile Screws as shown below.

Begin by using the Double L Bracket, 8mm screws and T-Nuts to attach the 2 x 2040 Centre Support Rails to the 2 x 2040 Base Support Rails (front and back). Note the centre support rails have the 40mm side parallel to the horizontal (face up) while the front and back rails have the 20mm face parallel to the horizontal (see image below).

Then place the Y-Axis, A-Axis and X-Axis Assembly on to the base, square everything and secure with Double L Brackets, 8mm screws and T-Nuts. Note that when the assembly sits on the front and back Base Support Rails there will be a space on both the left and right sides. The assembly can be placed so space is on either side (i.e., centred) or flush on one side with a large space on the other side. In this way, space can be used to support and assist in cable management.

Note the C-Beam of the Y-Axis and X-Axis is the same length as the 2040 Centre Support Rails. This means that the Y-Axis and A-Axis sit flush to the internal face of the Base Support Rails with the End Mount Plate sitting on the top of the Base Support Rails (See A below).

Mount the 2040mm extrusion onto the X-Axis, please do the following: Use the 15mm low profile screws, 9mm spacers, drop-in t-nuts and the L bracket to create 2 mounting points for the 2040 extrusion. The 9mm spacer offsets the L bracket which will provide the required spacing so as to not affect the gantry. Take care to mount the L-Brackets in the bottom channel of the C-Beam and the closest to the endplates on the C-Beam so as to not affect the movement of the gantry. Use the 8mm low profile screws and the sliding T-Nuts to fasten the 2040 V-slot onto the L brackets.

Mounting the CDC Bracket: Using the 9mm spacer to offset the 2040, attach the L bracket to the bottom channel of the C-Beam with a drop in T-Nut. This T-Nut can be place after construction of the X-Axis and does not need you to slide it in from the end

The CDC Bracket provided can mount directly to the back of the X-Axis Gantry through any of the spare holes. Here we have used one of the spare threaded holes. For how to mount the CDC to the mounting bracket please look at the manual.

This is the end result of the X-axis CDC on a Lead CNC Machine.

The Y-Axis CDC bracket can mount to what you have in place across the X-Axis. Here we have ours screwed into the end of the V-Slot that the X-Axis CDC is sitting on. Take note how the cables are running. Three cables (spindle, motor and limit switch) are going to the Z-Axis and so need to be run through both the Y and X-Axis CDC. The other two cables are for the Motor (in the picture) and a limit switch on the other side of the Extrusion (cannot see in the picture)

The Y-Axis CDC on our machine is mounted to a spare piece of V-Slot. This is not necessary, you can also have it sitting on your workbench, just remember to screw the end of it to the bench.

NOTE: Do this step after the machine is assembled, the electronic system is complete, and the machine can jog using the software. You need the stepper motors to be energised in order to tension the Lead Screw.

Jog the machine so that the gantry is closest to the end of the axis where the Nema23 Stepper Motor is fixed. For best results have the gantry approximately 50mm away from the Plate.

Loosen all the 8mm Lock Collars so that they freely move, except the Stepper Motor Side Outer (in-between the Flexible Coupler and Thrust Bearing on the Stepper Motor side). Thread the Lead Screw Tensioning Tool onto the end of the Lead Screw protruding at the end of the axis so that it is against the 8mm Lock Collar.

Turn the Lead Screw Tensioning Tool clockwise. As you turn this tool you will feel the Lead Screw begin to tension.

Initially turn the Lead Screw Tensioning Tool until the Nema23 Stepper Motor clicks over, when the Nema23 Stepper Motor clicks over it relieves the tension placed. The point just before the Nema23 Stepper Motor clicks over is the correct tension for the Lead Screw.

Again turn the Lead Screw Tensioning Tool so that the Lead Screw is at the correct tension, while holding the tensioning tool at this point, tighten the Tensioner Side Outer 8mm Lock Collar between the tensioning tool and the thrust bearing so that the tension is held in place by the 8mm Lock Collar.

Once the tension is held by the outer lock collars, ensure the 688ZZ bearings are in the recess of their respective plates, then push the respective inner lock collars against the 688ZZ bearings and tighten them in place.

Remove the Lead Screw Tensioning Tool and repeat for all axis that are to be placed under tension.

Note Before inserting lead screw please ensure the set screw in the Anti-Backlash Nut Block is not tensioned.

Step 1 Insert the lead screw and “screw” it into Anti-Backlash Nut Block. Adjust the set screw so that the lead screw is still easy to turn but there is extra resistance. Roll the Z-Axis Gantry onto the C-Beam. Adjust and tighten the Eccentric Spacers so the gantry rolls smoothly and without “wobble”.

Step 2 Insert 4x Tee nuts into each side of the C-beam, they should not be in the slot that the wheels of the gantry run over.

Step 3 Attach an 8mm Lock Collar to the Lead Screw then a 688Z Bearing. leave the Lock collar loose

Step 4 Using 20mm M5 Low Profile Screws attach the C-Beam End Mount.

Step 5 Follow the attached link back to 3.2 3.2 Z-Axis Actuator Assembly Part 2 Click here

Step 1 place a 60mm M5 Low Profile Screw in each corner of the gantry plate you attached the ACME Nut Block's too. For the screws with the larger holes use a 6mm Eccentric Spacer this will sit inside the hole, then add a Solid V Xtreme Wheel, 9mm Metric Aluminium Spacer, another Solid V Xtreme Wheel, and then another 6mm Eccentric Spacer facing the opposite way to the first spacer. Repeat this step once for the other large opening.

Step 2 For the left over screws place a 6mm Metric Aluminium Spacer, Solid V Xtreme Wheel,9mm Metric Aluminium Spacer, Solid V Xtreme Wheel and a 6mm Metric Aluminium Spacer.

Step 3 Add the extra C-Beam Gantry Plate XL and use M5-Nylon-Nuts to clamp it all together.

Roll the X-Axis - Z-Axis Assembly onto the C-Beam. Adjust and tighten the Eccentric Spacers so the gantry rolls smoothly and without “wobble”.

Insert 2x Tee nuts in the Top rear Channel, insert 2x Tee Nuts in each of the back Slots and insert 2x Tee nuts in the bottom rear Channel. These will be used later for the to attach the X-Axis to the Y-Axis.

Roll the X-Axis gantry onto the C-Beam. Insert the Lead Screw and “screw” it into the gantry. Adjust and tighten the 2 x 8mm Acme Nut Block so that the Lead Screw can turn easily with no backlash. Adjust and tighten the Eccentric Spacers so the gantry rolls smoothly and without “wobble”.

Step 1 Insert 6x Tee nuts in the Top rear Channel, insert 2x Tee Nuts in each of the back Slots and insert 2x Tee nuts in the bottom rear Channel. These will be used later for the to attach the X-Axis to the Y-Axis.

Step 2 Attach a 8mm Lock Collar to the Lead Screw followed by a 688Z Bearing.

Step 3 Using the 20mm M5 Low Profile Screws, attach the C-Beam End Mount.

Step 4 Attach the Thrust bearing to the Lead Screw then an 8mm Lock Collar, leave the Lock collars loose, these will be tightened later.

Step 1 Attach an 8mm Lock Collar to the Lead Screw followed by a 688Z Bearing.

Step 2 Using the 20mm M5 Low Profile Screws, attach the C-Beam End Mount.

Step 3 Attach the Thrust bearing to the Lead Screw then an 8mm Lock Collar and the 635x8mm Flexible Coupling, leave the Lock collar and the Flexible Coupling loose.

Step 4 Attach the motor using the 40mm and 6mm Spacers with 60mm M5 Low Profile Screw's. Adjust the Lead Screw so that the Lead screw and the Motor shaft are almost touching. Move the 635x8mm Flexible Coupling so that it sits centre over the gap between the Lead screw and the Motor shaft and fix the coupling into place. Tighten the Lock collar closest to the Motor only and ensure that the thrust bearing is firmly held in place.

Step 1 Attach the X-Axis Assemblys to the inside of the 250mm 2080 extrusion using 90 Degree Corner Brackets as shown below.

Step 2 Attach a 90 Degree Corner Bracket to the underneath of both C-beams and one to the top of the Slave X-Axis C-beam and the end of the 250mm 2080 extrusion as shown below. Repeat this step of the A-Axis

Step 3 Attach a Plate 90-5 to the X and Y axis using 8mm M5 Low Profile Screws as shown below.

Step 1 Attach 8x 90 Degree Corner Brackets to the XL plates as shown below using 10mm Screws.

Step 2 Attach the Z-Axis Gantry Assembly using 8mm M5 Low Profile Screws with the T-nuts inserted in 3.1A, the bottom of the Z-Axis should sit just below bottom of the C-Beam Gantry XL Assembly.

Tip Please note that you can adjust this height if required.

Step 4 Follow the attached link back to 5.0 5.0 Spoil Board

• Again, square your machine – for the X, Y and Z-axis.
• Using T-nuts, a baseboard can be attached to the base. This will strengthen the frame and create a work surface.

Special thanks to:

• Openbuilds and the Openbuilds forums
• The Open Hardware community
• Our fantastic customers, whose feedback constantly helps us improve our parts and the design of this great machine.