Ender 3 Lightweight DD Overhaul & Linear Rail

17.02.23 - Uploaded the STEP for the version I've been running for a while now. Main changes:

• Now using a bent 3003-H13 aluminum mounting plate instead of the original 3D printed mounting plate.
• Switched to Orbiter v2.
• Changed bed levelling probe to a PL-08N sensor.
• Changed the Rapido to now run in the UHF configuration as there are now CHT nozzles in Volcano length.
• Switched to a 25mm heatsink cooling fan to save on weight. Sadly it is louder but a resistor solved that for me.

This is my complete overhaul for the Ender 3's X axis. I used this to get my (currently) world record bedslinger #speedboatrace benchy at only 4m 48s.

After trying other people's designs and having issues or bad performance as they always lacked something or another, I finally decided to design my own X axis system.

I managed to push my printer up to 40kmm/s^2 accelerations at 360mm/s, with the bottleneck being my E3D High Torque steppers (I don't recommend, buy LDO 2504AC instead).

I'll be sharing the STEP file along with the STLs, and I would love to see the community's upgrades for my design!

This project requires:

Tools:

• Soldering Iron / Insert Tool
• Hex keys
• Pliers
• Tubing cutter / exacto knife

Hardware & Parts:

•  MGN12H 300mm rail
• Phaetus Rapido HF Hotend
• 28mm PTFE tube
• Orbiter v1.5 (might upload other versions for other extruders in the near future)
• 2x 5015 blower fans (I use 12v GDSTime fans, they run great at 24v and move a lot of air)
• 25x10mm fan or 40x10mm fan (25mm is lighter and more than enough cooling for the Rapido)
• BLTouch (Not required)
• ADXL345 Accelerometer (Not required)
• 2x M3*6mm screws (for the accelerometer, not required if not using one)
• 15x M3*8mm screws
• 4x M3*10mm screws (2 of which for the BLTouch, not required if not using one)
• 2x M3*14mm screws
• 4x M4*18mm screws
• 4x M2.5*8mm screws (Included with the Rapido Hotend)
• 2x M3 Nuts
• 6x M3 inserts (Designed for these: https://www.aliexpress.com/item/1005002615923810.html OD 4.2mm H3mm)

Printed Parts:

• Mount
• Duct L
• Duct R
• 25mm Fan Duct / 40mm Fan Duct, according to your hotend cooling fan size

Print settings and orientation:

I recommend 25% Gyroid infill, 4 walls  (+ alternate extra wall for mount), no supports, 0.2mm layer height, 0.5mm line width.

• Mount: Align to this specific face:

• Ducts L and R:
• 25mm / 40mm duct:

Build instructions: 

• Insert 6 M3 inserts to the Mount at these points:
• Cut out the built-in supports for the belt slots:
• Mount the linear rail to the front of the 2020 extrusion. You can use every second screw hole:

• Mount the Mount printed part to the linear rail using M3*8mm screws and connect the belt (red):
• Mount the hotend fan to your desired duct (25/40mm with 2x M3*14mm screws) and put in on the Rapido:  
• Mount the Rapido hotend and cooling fan using 4x M2.5*8mm screws. make sure the cable is going in the direction as shown in blue:
• Insert a 28mm piece of PTFE tube into the Rapido (red), and screw in the Orbiter (2x M3*10mm, blue):
• Mount the 5015 fans (4x M4*18) and BLTouch (2x M3*10 + 2x M3 nuts) with the screws as shown. The M4 screws thread directly into the plastic:
• Mount the Accelerometer (2x M3*6mm, red) and the 5015 fan ducts (4x M3*8mm, blue):

Tighten your belt and all done!

General Settings:

BLTouch offset: ~3mm Z (calibrate exactly manually), -49mm X, 0mm Y

Pressure advance: 0.032, smooth time 0.04s (also need to calibrate exactly yourself)

Fan speed: 30% or so for most stuff, 50% if extra cooling is needed. 100% basically exclusively for speed benchies :)

Klipper things:

[bltouch]
samples: 2
speed: 8
lift_speed: 20
samples_tolerance: 0.015
sample_retract_dist: 1.6
samples_tolerance_retries: 4
pin_move_time: 0.65
stow_on_each_sample: False

[safe_z_home]
home_xy_position: 166,117.5
speed: 240.0
z_hop: 5
z_hop_speed: 20.0

[bed_mesh]
speed: 200
horizontal_move_z: 6.5
mesh_min: 10,15
mesh_max: 200,225
probe_count: 5,5

[input_shaper]
shaper_freq_x: 58.2
shaper_type_x: mzv

*input shaper should also be calibrated manually, i'm giving my settings as a general guideline.

Final setup:

Happy printing!