Ender 5 s1 - Linear Rails Kit

This is a full Linear Rails mod for your Ender 5 s1 for the X and Y axis. 

This GREATLY improves rigidity and precision, and lowers the weight of the gantrys by 25% to 30%, which means greater quality at higher speeds. Also less unsprung weight shaking the printer around.

Below are the breakdowns per part in grams for the MGN12H and MGN9H models:

This mod requires raising the print bed by 5-6mm for mgn12 or 2-3mm for mgn9 as well as moving the end stops with the printable brackets. 

It has been fully tested with 40+ hours of printing with no major issues so far.  I have some minor clearance changes that I will be testing over the next few days, those changes are already included in these files. I'm using Klipper with a raspberry pi, but its possible you could use other systems with the ability to adjust the offsets.

All screw fittings that are not connecting to stock metal parts or the metal rail carriages are currently direct threading. It is recommended that you pre-thread all these holes with the size screw it is before full assembly. If there is interest I may do a threaded insert version as well, or maybe someone else wants to do this since I included the CAD models.

The Y-axis belts are held in with tension, and the X-axis belt is held in with a toothed clamping system. 

The extruder stepper cable should go behind the stepper and through the hole in the front bracket so it will reach the PCB. 

There are wire routing guides for front fan through left side and hot end heater and thermistor through right side as well as an optional buck convertor clip for a 4020 Noctua axial hot end fan. 

This is designed to use dual 5015 blower fans for part cooling but could be adapted to use the single stock 5015 fan with the included CAD file. 

You can use the stock breakout board or I have included an optional rear bracket that is compatible with the NBR breakout board as well if you have it, but it does require a rewire of the hot end thermistor plug since it is blocked(unavoidable) and a different plug. See Nathans channel and this video for some info on that.

If you need help I can usually be found on the NBR Discord server

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BOM:

Klipper or similar is required. installing that isn’t covered by these instructions as it’s assumed you already have klipper. 

RAILS: Choose wisely, clean and grease appropriately before mounting, go as expensive or as cheap as you feel comfortable with: 

• (3) sets of 300mm MGN12H linear rails
• +++ OR +++
• (2) sets of 300mm MGN12H and (1) set of 300mm MGN9H linear rails

FANS: (2) 5015 blower fans - Sunon 24v maglev or SoundOriginal 24v, (1) optional Noctua 4020 axial fan with tiny buck convertor

BED SPACER: Either the printed version included, or some other solid material like aluminum spacers from amazon (minimum 5-6mm height).

RAIL ALIGN TOOLS: Either the included printable versions or some other 2020 and 2040 rail alignment tools.

HARDWARE (socket head metric, some stock screws can be used):

• M2.5 x 12 : 2 - stock
• ---
• M3 t-nut : 18 - depends on rails chosen
• ---
• M3 x 4 : 1
• M3 x 6 : 17
• M3 x 8 : 24 - 18 of them depend on rails chosen
• M3 x 10 : 10
• M3 x 12 : 4
• M3 x 14 : 2 - stock
• M3 x 18 : 3
• M3 x 30 : 2 - depends on fan used, 30mm for 4020, 10mm for 4010
• ---
• M4 x 10 : 4 - stock
• M4 x 18 : 2
• M4 x 20 : 2
• M4 x 30 : 4
• ---
• M5 x 18 : 3 - stock - optional for added rigidity but more difficult to assemble

PRINTING:

Print high quality and slow for precision. I do 0.12 layer height, 20% infill, with standard supports, brim and ironing. Below are my recommended print orientation. These orientations are all in relation to how the part is installed on the printer.

ASSSEMBLY & INSTRUCTIONS:

The hardest part is getting the Y-axis gantrys mounted and aligned. 

First install the y-endstop bracket and switch. The right rail will sit flush against this and the left rail should be aligned front to back the same distance as right rail. Using rail alignment tools (printed or purchased) on each end, tighten down the right and left rails to extrusions. Start with outer most screws and work inwards first making them snug then tighten all to finish it.

Next is the Y-gantrys. Start by getting the top pieces on the extrusion while it is outside of the printer. This is meant to be a very tight fit and depending on your prints and your extrustion, you may have to put some muscle into it or even lightly sand inside the brackets so they fit and will slide without much force. Loosely screw in the screws from brackets to extrusion (tighten after carriages and rail tightened down). Next connect the bottom y-gantry brackets on both sides to top gantry brackets. Slide each gantry outwards and align with rail carriages and their mounting holes. Snug screw in the carriage screws through the brackets. Once aligned and satisfied with the fit, tighten down. Tighten down the stock extrusion screws from before. You can now install the y-axis belts on both sides by simply pushing them into place and tightening down the y-tensioners to proper tension.

Move the Y-axis back and forth and make sure there is no binding. If there is then you may need to loosen the rails and re-align, you can possibly do this with y-gantry still installed.

Next install the x-endstop switch on the right y-gantry.

Route the x-axis belt through both gantrys leaving it loose and unattached up front.

Install the x-axis tensioner on left y-gantry routing belt around it.

Install the x-axis stepper motor routing belt around it.

Then install the x-axis rail, using alignment tools and the same process as y-axis. It sits centered between the left and right y-gantry brackets on top of the extrusion.

Assemble the X-gantry in 2 main pieces, front and back.

Starting with front x-gantry, mount it to the x-rail carriage snug, the tight just like the y-rail carriages. Check for binding, smooth operation and clearance, it should be even when sliding back and forth. 

Install the x-axis belt by pushing them into their positions in the x-axis front bracket over the teeth one side at a time, screwing in the belt clamps over top of them.

Tighten the x-axis tensioner to proper tension.

Install the rear bracket onto the rear ducts with the rear screw first, followed by the CR-Touch and the other screws.

Install the PCB onto the rear bracket, first with the single lower screw, then the upper ribbon cable bracket screws.

Install the 2 rear 5015 fans by pushing them into their ducts, then aligning the top screws and screwing them into the rear bracket. (You can do this step later to make it easier to plug in connectors to pcb)

Mount the rear assembled x-gantry to the front x-gantry using the upper holes for stock board, or lower holes for NBR board.

Route the extrusion stepper motor cable through the hole in left rear of front x-gantry bracket, then place extruder down in its place, and lined up with its mounting holes. The cable should end up behind the extruder (there should be a few mm of space for it). Make sure the cable reaches the PCB, it is a very tight fit but will reach if done correctly. Screw in the front screws then the sides.

Seat the hotend in its position making sure the tube is fully inside the extruder. Route the cables through the right cable guide on the front x-gantry and up near the pcb where it will connect. Mount the hotend with its 3 screws, upper first, then the lower one.

Next comes the hotend fan. You can use the stock 4010 fan or a 4020 12v noctua fan with the buck converter clip(requires soldering). If using a 12v noctua 4020, install the clip onto the fan, then the buck into the clip. Mount the fan onto the hotend using the 2 stock fan spacers. Route the fan cable through the left cable guide on front x-gantry bracket.

Optionally install the stock fan cover using the mounting holes on the front x-gantry.

Install the ~6mm bed height spacers, otherwise the nozzle will not be able to reach the bed.

Connect all wires to PCB and the endstops.

Turn on printer and edit your klipper settings, see below.

Align the bed, z-height and do a bed mesh.

Print a benchy and pray.

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The fan ducts are based on my Dual 5015 fan mod which is a remix of Kevin Cooper's wonderful hard work on the stock part cooling fan model. The belt clamp teeth are based on the Voron 2.4 toolhead toothed belt clamping models. 

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Relevant klipper printer.cfg settings, specifically x_offset, y_offset, home_xy_position, mesh_min, mesh_max:

[stepper_x]
step_pin: PC2
dir_pin: !PB9
enable_pin: !PC3
rotation_distance: 40
microsteps: 16
endstop_pin: !PA5
position_min: -5
position_endstop: 220
position_max: 220
homing_speed: 80

[stepper_y]
step_pin: PB8
dir_pin: !PB7
enable_pin: !PC3
rotation_distance: 40
microsteps: 16
endstop_pin: !PA6
position_min: -2
position_endstop: 220
position_max: 220
homing_speed: 80

[bltouch]
sensor_pin: ^PC14
control_pin: PC13
x_offset: 0.0
y_offset: 46.7
speed: 20
stow_on_each_sample: false
samples: 1

[safe_z_home]
home_xy_position:110,63.3
speed: 200
z_hop: 10
z_hop_speed: 10

[bed_mesh]
speed: 150
mesh_min: 15, 46.7
mesh_max: 205,205
probe_count: 5,5
fade_start: 1
fade_end: 10
fade_target: 0
algorithm: bicubic

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UPDATES:

--v2: added mgn9 support for x-axis

--v3: fan ducts reworked for better flow