Project Dashboard LulzBot Mini 2 Final Mechanical Assembly Workflow

1 Components, Hardware, and Tools

Components Required:
1x- [HD-MS0033] GT2, 16 Teeth, timing pulley
2x- [HD-BL0033] Timing belt, 372 teeth, GT3 2mm pitch, 744 mm pitch length, 6 mm belt width, Neoprene
1x- [EL-MT0029] NEMA 17 Stepper Motor, Moons' - NOT INCLUDING wire harness
3x- [HD-MS0249] UV Resistant Cable Tie Down
1x- [PP-GP0484] X-Axis Belt Mount
1x- [PP-GP0493] Belt Tension Split Collar
1x- [PP-GP0494] Belt Tension Split Teardrop
1x- [PP-GP0132] X-Carriage
1x- [PP-GP0135] X-Axis Single Bearing Holder
2x- [HD-RD0035] 8mm Smooth rod, 315mm, 300 Series Stainless Steel
9x- [HD-WA0038] M3 Washer Black-Oxide
2x- [HD-NT0001] M3 Nylon lock nut
2x- [HD-BT0042] M3x30mm Bolt, SHCS Black-Oxide
2x- [HD-BT0116] M3x10mm Bolt, FHCS Black-Oxide
7x- [HD-BT0140] M3x6mm Bolt, BHCS Black-Oxide

Materials
Fixtures Needed
Final Frame Assembly

2 Install Y-Axis Motor

Flip the frame assembly so the Left Frame Plate is facing up. Then place the motor connector facing the left frame Plate [reference#1]. Motor orientation is critical

Using 4x- M3x6 BHCS [HD-BT0140] with 4x- M3 washers [HD-WA0038] secure the motor to the bottom frame plate, torque to 5 in*lbs.

Frame orientation
Reference#1
4x- M3x6 screws with 4x- M3 washers secure the motor
Torque to 5in*lbs

3 Connecting Motors

Flip the frame assembly so the bottom frame is facing up and so the Y-Axis motor is closest to you. Route the second longest wire, that has a motor connector, through the hole next to the motor. Plug in the wire.

Then remove back left screw from the Y-Axis motor and place the ring from the ground wire over the screw and then fasten the screw and ground wire into the motor. [reference#2] Make sure the ground wire is angled towards the motor connection wires

Repeat for the Z-Axis motors Flip Frame Assembly so the front of the printer is facing you and the top frame plate is facing up. Route the shortest wire to the Z-Axis left motor, and the longest wire to the Z-Axis right motor. Plug in both wires.

Remove the bottom right screw on the Z-Axis left motor and place the ring from the ground wire over the screw and then fasten the screw and ground wire into the motor. [reference#3] Make sure the ground wire is angled towards the motor connection wires

Remove the bottom left screw on the Z-Axis right motor and place the ring from the ground wire over the screw and then fasten the screw and ground wire into the motor. [reference#4] Make sure the ground wire is angled towards the motor connection wires

Using a Cable Tie secure all the wire routed through the Lower Strain Relief except the Z-Axis left motor wire

Secure the Y-Axis Motor wire and the Z-Axis right motor wire with a Cable Tie.

Route the second longest wire to the Y-Axis motor and connect
Reference#2
Place the ground wire ring terminal on the screw
Make sure the ground wire is angled towards the motor connection wires
Route the longest wire to the Y-Axis right motor
Reference#3
Place the ground wire ring terminal on the screw
Make sure the ground wire is angled towards the motor connection wires
Route the shortest wire to the Z-Axis right motor
Reference#4
Place the ground wire ring terminal on the screw
Make sure the ground wire is angled towards the motor connection wires

4 Install Cable Ties

Flip the frame assembly so its resting on the right frame plate

Using a Cable Tie secure all the wire routed through the Lower Strain Relief except the Z-Axis left motor wire. Tighten the cable tie then cut off the excess

Secure both the Y-Axis Motor wire and the Z-Axis right motor wire with Cable Ties. Tighten the cable ties then cut off the excess

Placement of cable ties
Make sure blue wire lay flat and are under the motor connection wires

5 Install Y-Axis Drive Belt

Flip the assembly upside down so that it rests on the top frame plate with the Y-Idler to your right.

Cut the Timing Belt [HD-BL0033] at an angle to assist feeding through the Y-Idler.

Loop the belt around the left belt mount post as pictured.

Run the timing belt with the teeth on the inside around the timing pulley, then run the timing belt around the idler bearings and back to the belt mount

Loop the belt around the right belt mount post

Tighten the left M3x12 SHCS [HD-BT0039] to firmly hold the belt.

Grab the loose end of belt (on the right) with a pair of needle nose pliers and pull the belt tight, tighten the right side of the Belt clamp

Use setting number 2 on the 508C Sonic Tension Meter to check the tension in the belt (see OHAI) When measuring the mini 2 belt tensions on the X and Y, push the carriages to the idler side.

The tension should be between 23-27 Newtons. It is best to set the belt towards the top of the range, because they will settle to a lower tension after butn-in.

Trim the excess timing belt, leaving about 20mm on each side.

Flip the assembly upside down
Cut a belt at an angle
Loop the belt around the left belt mount post
Belt around Y-Motor Pulley
Belt routed thought Y-Idler
Wrap around right belt mount post
Tighten left M3x12 SHCS to secure the belt
Grab the belt exiting near the right belt mount post
Twist to apply tension and tighten right M3x12 SHCS
Trim excess belt

6 Install X-Axis Drive Belt

Cut a Timing belt [HD-BL0033] in half, then slide one side through the Belt Tension Split Collar [PP-GP0493] with the teeth facing up. Make a loop around the Belt Tension Split Teardrop [PP-GP0494] then feed the timing belt through the Belt Tension Split Collar making sure the belt teeth lock together then pull belt through until the Belt Tension Split Teardrop is tight against the Belt Tension Split collar (Make sure the point of the teardrop is facing the split collar, as shown)

Feed the belt through the top of X-End Idler Assembly and wrap it around the bearing (with the teeth touching the bearing), then route the belt through the X-End Motor Assembly

Take the X-Axis Belt Mount [PP-GP0484] and feed the loose end of the Timer Belt through the belt slot on the side of the X-Axis Belt Mount, then push the belt through until it come out on the bottom side of the X-Axis Belt Mount and feed it back through the side belt slot so the teeth lock together. Then pull the locked belt until tight to ensure X-Axis Belt Mount is secured on the Timer Belt.

Place two M3 Nylon lock nuts [HD-NT0001] inside of the X-Axis Belt Mount with the nylon ring facing the X-Axis Motor and press them into the nylon lock nut holders (as shown), then place the X-Axis Belt Mount in the belt mount jig and make sure the top door can fully close. (If it doesn't close fully push the nuts farther into the nylon lock nut holders)

Take a M3x10mm FHCS Bolt [HD-BT0116] with a M3 Washer [HD-WA0038] and place them in one of the holes on the Belt Tension Split Collar with the threads pointing towards the X-Axis Belt Mount, repeat for the other hole.

Pull both ends of the Belt together, make sure the two M3x10mm FHCS Bolts just barely reach the two Nylon Lock Nuts in the X-Axis Belt Mount. then screw in the two M3x10mm FHCS Bolts into the two Nylon Lock Nuts make sure not to go fully through the Nylon Lock Nut or less the jig might break. Once Both sides of the Timer Belt are secured take the Jig off and tighten the two bolts until the belt is tight.

Note: (Belt should be tight and not loose, if belt is too loose pull on the Belt Tension Split Teardrop so belt slides out of the Belt Tension Split Collar and pull more of the Timer Belt through the Belt Tension Split Collar, then repeat the last step until belt is tight)

Cut Timer Belt
Slide belt through Belt Tension Split Collar
Make a loop for the Belt Tension Split Teardrop and lock teeth together
Place Belt Tension Split Teardrop in the belt loop make sure the orientation is correct and pull tight
Feed belt through the X-End Idler Assembly
Feed belt through the X-End Motor Assembly
Feed belt through the belt slot on the side of the X-Axis Belt Mount
Push the belt through
Wrap belt around then lock belt teeth together
Place Nylon Lock Nuts in the X-Axis Belt Mount
Nylon Lock Nuts in place and X-Axis Belt Mount placed in jig
Connect both ends of the timer belt
Once both bolts are secure then remove jig and make sure belt is tight

7 Install Carriage Assembly

Using a 8mm part reaming tool, ream out the two 8mm smooth rod holes on the X-End Motor Assembly [PP-GP0130] and on the X-End Idler Assembly [PP-GP0131]

Ream out the bushings on the X-Carriage [PP-GP0132] and on the X-Axis Single Bearing Holder [PP-GP0135]

Slide both 8mm smooth rods [HD-RD0035] through the X-End Idler Assembly then slide the X-Carriage on the top smooth rod, Make sure the flat side of the X-Carriage is facing the front of the printer.

Slide the X-Axis Single Bearing Holder on the lower smooth rod with the flat surface touching the X-Carriage making sure the holes align with the X-Carriage.

Place the extruded metal jig on the printer refer to [reference#5] to ensure the right placement. Then Place "L" shaped jig between the X-Axis motor and the left frame plate with the long end pointing down refer to [reference#6] to ensure the right placement

Slide the two smooth rods so they are seated in the two 8mm smooth rod holes on the X-End Motor Assembly, once the rods are fully in the holes then secure the rods with the two set screws located on the X-End Idler Assembly

Connect the X-Axis Single Bearing Holder and the X-Carriage using 3x M3x6mm BHCS Bolts [HD-PT0140] with 3x M3 Washers [HD-WA0038]

Then connect the Belt Tension Split Collar [PP-GP0493] to the X-Carriage with 2x M3x10mm FHCS Bolts [HD-BT0140]

Ream out the smooth rod holes on the X-End Motor assembly and the X-End Idler Assembly
Ream out the X-Carriage and the X-Axis Single Bearing Holder
Slide both smooth rods through the X-End Idler Assembly
Slide the X-Carriage over the top smooth rod
Slide the X-Axis Single Bearing Holder on the lower smooth rod
This is how the X-Carriage and the X-Axis Single Bearing Holder should look for the back of the printer
[reference#5] The jig should be positioned like this
[reference#6] The jig should be positioned like this with the long side of the "L" between the motor and left frame plate
Smooth rods in place
Secure smooth rods with set screws
Attach the X-Axis Single Bearing Holder to the X-Carriage
Attach the Belt Tension Split Collar to the X-Carriage

8 Checklist

Look over the Mini 2 X-Axis Assembly Checklist and make sure every step was followed.

Checklist for the X-Axis Assembly
Done! Take me home