This mod was desinged for the Sidewinder X1 and a MGN12H Linear Rail. I wanted there to be as little changes as possible to the stock appearance and firmware of the machine. 

It is used to convert the Y axis from v-slot wheels to a single linear rail. From my testing it has shown to be more than suitable enough for higher speed 3D printing when compared to two rails on the Y axis. Two rails did not provide any noticeable benefit over 1 to justify the extra cost.

You'll want to make sure your printer is dialed in and accurate, otherwise the screws won't recess into the channels properly.

Before starting, raise your Z axis to 150-250mm to give yourself plenty of room to work with.

Remove the glass bed and place it gently behind the machine to avoid damaging any cables. I recommend replacing the springs with some silcone leveling columns (16mm). Not only will these save you the headache of not falling off like the springs do, they will also give back some of the Z height that you will lose when converting to linear rails. 

Unscrew the Z endstop and attach it to a M3 T nut. Don't tighten it all the way yet since you do not know where your new endstop will be.

Disassemble the Y Axis. Remove the belt, the wheels, front metal pulley/tension arm, and the Y carriage. Unscrew the Y endstop and set it aside where it won't be damaged.

There are 2 M5 screws running down the center of the aluminum extrusion. Remove these two screws and tighten the other 4. This center extrusion is where the linear rail will be installed.

Take only the blue aluminum Y carriage and prepare to assemble.

Then follow this order:

Linear rail to Y aluminum:

• 1x 450mm Linear rail with TWO MGN12H carriages
• 20x M3 6mm Screws
• 20x M3 slotted SLIDING T nuts
• Try to center the Rail as much as possible between the front and back of the printer. Leave enough room for the Y endstop but not too far back where the carriage will slide off the rail when fully extended in either direction.

3D printed Y Carriage Adapter Plate

• 100% infill
• Printed in PLA
• 0.2mm-0.3mm layer height
• At 70mms/0.2mm it takes around 2hours and 30minutes

Right side of Y carriage to Faceplate

• 3x M6 16mm Hex socket head
• 3x M6 washer
• 3x M6 nuts

Left side of Y Carriage to Faceplate

• 1x M4 16mm Hex socket head (in the CENTER hole)
• 2x M4 40mmHex socket head (these will be used to attach the belt the carriage)
• 3x M4 washer
• 3x M4 nuts

Faceplate to MGN12H Carriages

• 8x M3 6mm Hex socket head
• Tighten the screws in an 'X' pattern, while alternating between EACH carriage.
• DO NOT TIGHTEN ONE CARRIAGE FULLY BEFORE TIGHTENING THE OTHER. THEY NEED EQUAL PRESSURE APPLIED TO BOTH.

It should feel like the Carriage is gliding across the rail. If it is difficult to slide you may have incorrectly/over tightened the screws to the MGN12H blocks.

• Please note that if you decided to buy cheap chinese rails that you may need to relube/rebuild them. You get way you pay for.

Put the Front Pulley/Tensioner back in place.

Belt to Y Carriage:

• GT2-6 Belt with steel wire (length at least 1 meter, i reccomend 2 meters in case of mistakes)
  • (Stock belt is not long enough and steel wire prevents stretching)
• 2 Zip ties

Zip tie the belt to the upper 40mm screw ensuring it is at the same height as the pulleys with the teeth side together.

Make sure the teeth are facing the correct way and feed the belt around the Y motor pulley, and all the way down to the Front pulley.

Feed the belt through the Front pulley, and bring it to the rear 40mm screw.

Zip tie the belt to the lower 40mm screw ensuring it is at the same height as the pulleys with the teeth side together.

Cut off the excess belt.

Tension the Y belt using the front pulley/tensioner, but not too tight.

Now to replace the Y end-stop.

• 1x M3 16mm hex socket head
• 1x M3 Washer
• 2x M3 nuts.
• 1x M3 T nut

The goal is to have the MGN12H Carriage trigger the endstop, not the Rail.

Put the screw through the endstop, then the two nuts. Bring them all the way up to the base of the endstop but do not tighten them. Insert a T nut into the rail and screw the endstop in and adjust it so the endstop sits 3-4mm from the the rail itself and above it. When the carriage slides all the way back, the endstop will be triggered by the carriage sliding just slightly over the edge of the linear rail. No the ball bearings are not exposed so it should be fine. I am currently in the process of designing a 3d printable fix that is more suitable.

Turn on your printer and test a Y home to make sure the sensor is in the right position and working. BE READY TO PANICK SWITCH OFF INCASE SOMETHING WENT WRONG.

If the Y home succeeded you can turn off the printer.

Reinstall your glass bed, and tighten the screws till you squish the silcone columns till you feel restistance.

Turn the printer back on.

Manually lower the Z height till the nozzle is about 1-2mm from the bed.

Now reinstall the Z-endstop at this new position.

Test a Z home. BE READY TO PANIC SWITCH OFF.

If it succeeds you are ready to level your bed and start printing!