8. XY Plane
Paste the X & Y Endstops
X endstop
CF extruder carriage
Microswitch endstop (1)
Bolt m2 x 8 (2)
Y endstop
Right Y-min endstop mount (STL here)
Microswitch endstop (1)
Bolt m2 x 8 (2)
Exam
Make sure the superglue is cured, and the button is still clickable.
Actions
The holes for the endstop on the CF extruder carriage are a bit larger in some versions, so the first step here is to apply superglue between endstop and extruder carriage and let it cures. The two m2 bolts act as positioning pins only.
(Sorry for the inconvenience. 🙏 The holes in the extruder carriage will be shrunk for the M2 bolts.)
Do the same thing to the Y endstop.
Y Linear Guides
Y rail ⇔ Y frame
240mm MGN9C linear guides (1)
Bolt M3 x 08 (x5)
Nut M3 (x5)
XY joiner ⇔ Y linear block
Countersunk bolt m3 x 06 (4)
Right Y-min endstop mount ⇔ Right Y frame
Bolt m3 x 10 (1)
Nut m3 (1)
(Optional) Left Y-min endstop mount ⇔ Left Y frame
Bolt m3 x 10 (1)
Nut m3 (1)
Y frame ⇔ frame
RH bolt m4 x 10 (3)
Flanged nut m4 (3)
Actions
Assemble Y linear guides and XY joiners as shown in the picture, but attach one microswitch endstop to the right Y frame only (for a shorter distance to the control board), no microswitch is used at the left Y frame.
Refer to Hardware type & legends for the fonts and meanings in the labels.
X Linear Guide
XY joiner ⇔ CF X plate
Countersunk bolt m3 x 12 (3)
Nylon nut m3
X linear guide ⇔ CF X plate
MGN12C 270mm linear guide (1)
Bolt m3 x 15 (4)
Washer M3 x 8 x 1.0 (4)
Nylon nut m3 (4)
Actions
Important! Check Smoothness
Exam
Before installing the XY belts, if you feel uneven pressure while sliding the X rail along Y direction, loosen and re-tighten these bolts gradually and evenly.
Criteria: the front and rear end of the two Y rails should be on the same XY plane. Please check the joints between:
Y rails and Y frame pieces
Y frame pieces and the whole frame
Criteria: X and Y axes should be perpendicular to each other. Please check the joints between:
XY joiners and Y linear blocks
XY joiners and CF X plates
Fasten nuts in stages
Fasten ALL nuts to 50% --> ALL nuts to 75% --> ALL nuts to 100%.
Extruder Carriage
Carbon fiber extruder carriage (1)
Carbon fiber upper belt clamp (1)
Carbon fiber lower belt clamp (1)
Printed X endstop trigger cap (STL here)
Standoff M3 x 22 (4)
Bolt M3 x 15 (8)
Washer M3 x 8 x 1.0 (16)
Nylon nut M3 (4)
Countersunk bolt M3 x 06 (4)
Actions
Follow the steps below to assemble the extruder carriage. We'll leave the pancake E stepper and BMG extruder later in the Chapter 10. Extruder.
Attach upper & lower belt clamps to extruder carriage but don't fasten bolts at this moment.
Fasten the extruder carriage to the X linear block.
Clip the X endstop trigger cap onto the left XY joiner.
(Beta version only)
Extruder Carriage
Extruder Carriage
X-min microswitch endstop ⇔ Extruder carriage
RH m2 x 08 (2)
[For beta version only] The diameter of holes on the microswitch is only 1.2mm in diameter. Please expand the holes with a 1.8 or 2.0 mm drill bit first, or glue them to the endstop mount with superglue. Will source microswitch with 2mm holes for later kits.
Extruder carriage ⇔ MGN12C X linear block
Countersunk bolt m3 x 06 (4)
Upper/Lower belt clamps ⇔ Extruder carriage
Bolt m3 x 15 (4)
Nylon nut m3 (4)
Washer m3 x 8 x 0.8 (4)
Actions
Assemble the extruder carriage as shown in the pictures.
Assemble the BMG extruder adaptor between extruder and stepper later in Chapter 10.
[Optional] Servo42C fix
Servo42C (S42C) stepper
Nut m3 (4)
M4 nuts (4, or eight M3 x 6 x 1 washers)
Loctite 243 thread locker recommended
(The OD 6mm washers were not included in the kits before 2022 Jul)
Exam
The magnet sensor & pins on the Servo42C MUST NOT touch the stepper.
There should be NO GAPS between the upper/lower caps and the body of the stepper.
Actions
The elasticity of nylon washers used between S42C PCBA and the stepper can be the cause of loose bolts, and creating skewed, grinding stepper shaft, especially in a heated chamber.
MKS Servo42C
XY Steppers
XY Steppers
Check the next page if you're using BigTreeTech S42C's.
Servo42C stepper ⇔ Stepper mount
Printed stepper nut holder (1) (STL here)
Bolt m3 x 06 (4)
Flanged nut m4 (4)
2GT 16T pulley 5mm-bore, not 6mm-bore (1)
XY stepper mount ⇔ frame
RH bolt m4 x 10 (4)
Exam
Take the vents on the frame as references, and make sure the orientations of S42C-to-stepper cables are correct.
Make sure the orientation of the pulleys are correct.
Actions
Assemble the nuts holder, stepper mount and stepper as shown below.
The socket orientations of the two Servo42C's should be different for the cables to be hidden properly.
If you ordered the enclosure kit, leave the stepper covers, two pieces of 0.3mm steel sheets, untouched in this step. They are relative fragile and require a specific procedure to be folded in one time. Check chapter 13. Enclosure.
BigTreeTech S42C's. XY Steppers
Check the previous page if you're using MKS Servo42C's.
S42C stepper ⇔ Stepper mount
Printed stepper nut holder (1) (STL here)
Bolt m3 x 06 (4)
Flanged nut m4 (2)
Nut m4 (2)
2GT 16T pulley 5mm-bore, not 6mm-bore (1)
XY stepper mount ⇔ frame
RH bolt m4 x 10 (4)
Exam
Make sure the orientation of the pulleys are correct.
Actions
Assemble the nuts holder, stepper mount and stepper as shown below.
Note the socket orientations of the two S42C's are different for the cables to be hidden properly.
If you ordered the enclosure kit, leave the stepper covers, two pieces of 0.3mm steel sheets, untouched in this step. They are relative fragile and require a specific procedure to be folded in one time. Check chapter 13. Enclosure.
CoreXY Belt Route
Steel pin 2x10 mm (2, optional)
Gates GT2 belt, 135cm (2)
Actions
The left stepper and the upper belt use the upper belt clamp.
The right stepper and the lower belt use the lower belt clamp.
Inserting a flat head screw driver (step 1a) helps passing the belt through the hole (step 1b) in the belt clamp.
Step 2. follow the left CoreXY belt route in the picture below.
Step 3. fold and mesh the belt, with an optional steel pin inserted. Insert the folded belt from the left side and loosely clamp the belt between the two CF parts.
(The optional pin thickens the belt and further prevent slipping.)
Step 4. pull and tense the belt, fasten the nuts.
Step 5. do the same to the lower, right belt.
[Beta version only]
Note that the Beta version has 2 pins used at both ends of a single belt, while the newer version has one end extruded out of the belt clamp for you to pull and tense the belt.
Proper Belt Tension
In this SK-Tank video the XY belt tension is too low and belts vibrate when the extruder moves quickly. The vibration propagates back to the extruder and results in undesired vertical fine artifacts.
In SK-Cube, such vibration is milder since belts are shorter than the belts in SK-Tank.
Please tense you XY belts to a level that they won't vibrate in the fastest speed in your common use cases. Note that too high belt tension will bring extra load to the stepper and reduce the life of pulley system.