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Lead CNC V3
Mechanical Assembly Instructions
About The Maker Store Lead CNC Kit
This is the Maker Store kit of the Open Source Lead CNC Machine. The Lead Version 3 is a super-strong, accurate and easy to assemble CNC machine-made using off the shelf parts with easily customisable options.
The Lead CNC Machine was originally designed by Mark Carew and the design is licensed under CC – Attribution – CC BY. An easy to assemble CNC machine based on C-Beam, V-Slot, Xtreme Solid V-Wheels and TR8x8(P2) Leadscrews it is strong, accurate and reliable.
It has been designed to accurately cut foams, woods, plastics and aluminium to 0.05-0.10mm accuracy or better.
Functional engineering parts, toys, signs or anything else that can be imagined, can be made on the Lead CNC Machine.
The Maker Store kit has a couple of small differences from the design published by Mark Carew. Most notably are the inclusion of the High Z Mod as standard, use of Black Corner Connectors in place of Cast Brackets in order to increase rigidity and the addition of a Lead screw tensioning system.
The Lead CNC Machine is a 4 axis (3 + 1) machine, this means there are 3 physical axis (X,Y,Z) and a slave axis of Y which is called the A Axis.
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 such as a dynamic actuator frame rather than a static frame.
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:
Tools Required
You will need the following tools:
- 3mm Allen Key
- 8mm Spanner
- 10mm Spanner
- Screw Drivers
- Builder’s Square
- Lead Screw Tensioning Tool
Pre-Assembly Notes
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 drawings and fully understand the instructions.
When attaching parts, if a part is requiring significant force to attach, 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 [email protected], we are happy to help!
The parts required to complete the build are listed below:
Bill of Materials (BOM)
1.0 Wheel Assembly
The Solid V Wheel Kit listed in the Bill of Materials comes with the parts mentioned in the table above. Take these parts out of the kit pack and start the assembly.
Step 1: Place the Solid V Wheel (B) on a flat surface and insert one of the 6252RS Bearing (A) in the Solid V Wheel (B).
Step 2: Flip the Solid V Wheel (B) and place the Precision Shim 10x5x1MM (C) inside the Solid V Wheel, on top of the inner race of the already inserted bearing (A).
Step 3: Insert the other 6252RS bearing (A) in the Solid V Wheel (B) so that it rests on the Precision Shim 10x5x1MM (C). This will complete 1 wheel assembly.
Step 4: Repeat the steps above for the remaining wheel kits. Refer to your Bill of Materials (BoM) for a complete account of Solid V Wheels needed for this build.
Pro Tip: Use a mallet to gently tap the bearings (A) inside the Solid V Wheel (B).
Pro Tip: Use one of the longer bolts to align everything (A,B,C) by threading the parts on one by one.
2.0 Y and A-Axis Assembly
2.1 Y and A-Axis Gantry
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. On the same plate that you attached the ACME Nut Block’s too, insert 60mm M5 Low Profile Screws into each of the corners, also insert a 60mm M5 Low Profile Screw into the hole just above the Maker Store logo.
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 Slot Washer – 15x5x2mm and M5-Nylon-Nuts to clamp it all together.
Step 7. Repeat the above steps 1-6 more time to make another Gantry.
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Step 8. 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 9. On each of the 90 Degree Angle Corner Connector’s, attach a Tee Nut using an 8mm M5 Low Profile Screw.
Step 10. Slide the V-Slot 2080 500mm 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.
Click on the image(s) to expand
2.2 Y and A-Axis Actuator Assembly
This section uses the gantry assembly made in section 2.1, as well as the following parts:
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 picture above.
Step 8. Repeat Steps 1-7 to make the A-Axis (second Y-axis).
Note: The Y-Axis and A-Axis should be mirror images of each other.
Step 9. Attach an 8mm Lock Collar to the Lead Screw followed by a 688Z Bearing.
Step 10. Using the 20mm M5 Low Profile Screws, attach the C-Beam End Mount.
Step 11. 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 12. Attach the motor using 50mm 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 13. Repeat Steps 1-4 to complete the A-Axis.
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These assemblies will be known as “yA” and “yAs” in the proceeding BoM’s.
3.0 Z-Axis
3.1 Z-Axis Gantry's
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.
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Step 4. Repeat steps 2 & 3 to complete the Z-Axis Slave Gantry.
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3.2 Z-Axis Actuator Assembly
This section uses the gantry assemblies made in section 3.1, as well as the following parts:
Note: Before inserting lead screw please ensure the set screw in the Anti-Backlash Nut Block is not tensioned.
Step 1. Roll the Z-Axis Slave Gantry onto the C-Beam. Adjust and tighten the Eccentric Spacers so the gantry rolls smoothly and without “wobble”.
Step 2. 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 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.
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Step 5. Attach an 8mm Lock Collar to the Lead Screw then a 688Z Bearing. leave the Lock collar loose
Step 6. Using the 20mm M5 Low Profile Screws, attach the C-Beam End Mount.
Step 7. Attach the 635x8mm Flexible Coupling, leave the Lock collar and the Flexible Coupling loose.
Step 8. 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.
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This assembly will be known as “zA” in the proceeding BoM’s.
4.0 X-Axis
4.1 X-Axis Gantry's
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 Slot Washer – 15x5x2mm and M5-Nylon-Nuts to clamp it all together.
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Step 7. Repeat steps 2-6 above to make the X-Axis Slave Gantry.
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4.2 X-Axis Assemblies
This section uses the gantry assemblies made in section 4.1, as well as the following parts:
4.2.1 X-Axis Slave Assembly
Step 1. Roll the X-Axis Slave Gantry Assembly onto the C-Beam. Adjust and tighten the Eccentric Spacers so the gantry rolls smoothly and without “wobble”.
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Step 2. 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.
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Set aside this assembly for now. This assembly will be known as “xAs” in the proceeding BoM’s.
4.2.2 X-Axis Assembly
Step 3. 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”.
Click on the image(s) to expand
Step 4. 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.
Step 5. Attach a 8mm Lock Collar to the Lead Screw followed by a 688Z Bearing.
Step 6. Using the 20mm M5 Low Profile Screws, attach the C-Beam End Mount.
Step 7. Attach the Thrust bearing to the Lead Screw then an 8mm Lock Collar, leave the Lock collars loose, these will be tightened later.
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Step 8. Attach an 8mm Lock Collar to the Lead Screw followed by a 688Z Bearing.
Step 9. Using the 20mm M5 Low Profile Screws, attach the C-Beam End Mount.
Step 10. 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 11. Attach the motor using the 50mm 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.
Click on the image(s) to expand
This assembly will be known as “xA” in the proceeding BoM’s.
5.0 X-Axis to Y-Axis Assembly
Step 1. Attach the X-Axis Assemblies to the inside of the 250mm 2080 extrusion using 90 Degree Angle Corner Connector as shown below.
Step 2. Attach a 90 Degree Angle Corner Connector 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.
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6.0 Base Assembly
Step 1. Begin by using the Double L Brackets, 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). For the 1000 x 1000 and 1000 x 1500 we recommend you space the 2040 Centre Support Rails approx 300mm from the ends 2040 Base Support Rails (front and back), for the 1500 x 1500 we recommend you space the 2040 Centre Support Rails approx 400mm from the ends 2040 Base Support Rails (front and back).
Step 2. 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 the space is equal on either side (i.e., centred) or flush on one side with a large space on the other side. In this way, the space left over 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).
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7.0 Z-Axis to X-Axis
Using the 12mm screws attach the Z-Axis assembly to the X-Axis gantry plates, there will be threaded holes in the Z-axis plates to use with the 12mm screws.
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Step 1. Attach 8x 90 Degree Corner Brackets to the XL plates as shown below using 10mm Screws.
Step 2. Attach 8mm M5 Low Profile Screws with the T-nuts in each of the 90 Degree Corner Brackets.
Step 3. Using 8mm M5 Low Profile Screws with the T-nuts attach the V-Slot 2080 500mm by sliding it in between the brackets, the V-Slot 2080 500mm should sit inline with the bottom C-Beam Gantry XL Assembly.
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8.0 Final Additions
8.1 Cable Drag Chain Support
Step 1. Attach the Cable Drag Chain Mounting Bracket V2 to the bottom slots of the xA axis using the M5 Button Head Screws- 8mm and M5 Spring Loaded Tee Nuts. Repeat on the opposite end of the xA axis.
Step 2. Mount the V-Slot 20 x 60mm – 1000 or 1500 (depending on the size of your X-Axis) to the top of the Cable Drag Chain Mounting Brackets by inserting 2 Tee Nuts – M5 into the bottom front slots on the V-Slot 20 x 60, then securing the components in place with M5 Low Profile Screws – 8mm.
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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.
8.2 Tensioning
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.
Step 1. 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.
Step 2. 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.
Step 3. Turn the Lead Screw Tensioning Tool clockwise. As you turn this tool you will feel the Lead Screw begin to tension.
Step 4. 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.
Step 5. 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.
Step 6. 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.
Step 7. Remove the Lead Screw Tensioning Tool and repeat for all axis that are to be placed under tension.
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8.3 Limit Switches
NOTE: These are additional add-on packs and do not come with the base machine kit.
There are two types of mechanical limit switches available for the Lead CNC v3. The Micro Limit Switch (Type A) and the CMV103C Long Arm/CMV104D Short Arm (Type B). See images below for reference.
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8.3.1 Limit Switch Assembly
To assemble the CMV103C/104D Limit Switch, use the BoM and follow the steps below:
Step 1. Insert 2x 12mm M3 Cap Head Bolts (3) into the two holes of the CMV103C Limit Switch (1)
Step 2. Referring to figure 4, line up the appropriate threaded holes of the Limit Switch Plate V2 (2) with the 12mm M3 Cap Head Bolts (3) so that the limit switch lever hangs off the front of the plate.
Step 3. Finally, screw in the 12mm M3 Cap Head Bolts (3) into the threaded holes of the Limit Switch Plate V2 (2).
Click on the image(s) to expand
It is possible to invert the limit switch for right-side sensing.
To mount the limit switch and plate to your machine:
Step 4. Line up the limit switch arm with a suitable flat surface to trigger the limit switch lever on your machine. This can be a gantry plate, bearing or a V-Wheel.
Step 5. Insert the Spring Loaded Tee Nuts (5) into a V-Slot channel (Figure 6) and then line up the slot of the limit switch plates with the Spring Loaded Tee Nuts (Figure 7). Use an Allen key to fasten the M5-Button Head Screws-8mm (4) into the Tee Nuts through the plate to secure the micro limit switch assembly (Figure 8).
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This completes the assembly of the CMV103C/104D limit switch kit.
To assemble the Micro Limit Switch, use the BoM and follow the steps below:
Step 1. Insert the 2x M3-Cap Head Screw-10mm (1) through the Limit Switch Plate (5) so that the screws are lined up (horizontally or vertically). Configuration is dependant on how you plan to mount the limit switch plate.
Step 2. Line up both holes of the Micro Limit Switch (4) with the 2x M3-Cap Head Screw-10mm (1), secure the Micro Limit Switch to the plate.
Note: Some force may be needed if the Micro Limit Switch has not been threaded beforehand.
Note: Do not over tighten!
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Step 3. To mount the Plate and Micro Limit switch to a machine or V-slot extrusion, insert the M5-Button Head Screw-8mm (3) through the larger slot in the Limit Switch Plate (5) and the Slot Washer – 15x5x2mm (6), then secure by screwing the Spring Loaded Tee Nut (2) onto the M5-Button Head Screw-8mm loosely. See figure 7 for reference.
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Step 4. Line up the red limit switch with a suitable flat surface on your machine, such as a gantry plate, bearing or even a V-Wheel. Insert the Spring Loaded Tee Nut (2) into a V-Slot channel, then use an Allen key to turn the M5-Button Head Screw-8mm (3) clockwise into the tee nut through the plate to secure the micro limit switch assembly.
Limit switch kits can be placed in any location you can secure it. For our machines we suggest limits and homing to be located on the Front of the Y – axis, Left of the X – axis, and Bottom of the Z – axis.
8.3.2 Limit Switch Mounting
Placement for the CMV103C/104D Limit Switch (left column) and Micro Limit Switch (right column) are shown in the images below. Please see the Micro Limit Switch mounting guides for full mounting, wiring and placement instructions.
X-Axis Mounting
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Y-Axis Mounting
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Z-Axis Mounting
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Finished
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Congratulations, the mechanical portion of the machine assembly is now complete.
The machine must be commissioned prior to use. Take a look at our Commissioning Guide for assistance with Squaring, Lead Screw Tensioning and Tramming.
Please click HERE to go to the commissioning Guide.
Credits
Special thanks to:
- The Open Hardware community
- Our fantastic customers, whose feedback constantly helps us improve our parts and the design of this great machine.4
- Mark Carew the designer of the Lead Version 1
- Aaron From Maker Store who redesigned the Lead to Version 3