This is a modification to replace the Y-Axis rods and bearings by linear rails on a Full Bear MK3 printer. The rail holders are remixed from the original rod holders (same aesthetic) designed by Grégoire Saunier (https://github.com/gregsaun/prusa_i3_bear_upgrade).

To use this mod you need:

• Two MGN12 rails (328-329mm length)
• Three MGN12C blocks (four M3x8 screws, two M3x12 screws and two square nuts per block). Also you can use a MGN12H instead MGN12C on the right rail.

I have used these ones: https://www.amazon.es/gp/product/B07GBNWDTL/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&th=1&fbclid=IwAR2jLiou4xDX38AW4K89YjqAeFm7EX_YhgCjvifV3m2hu0477jndw4TpVVw

I have printed and checked these parts. The printer has passed the selftest and XYZ calibration, so are well measured.

My goal is to do the simplest way to install these rails without modifying too much the Full Bear design. The question is: What are stronger to be installed in air, rods or rails?

UPDATES:

2019/05/16:

• Added a MGN12H carriage block if you want to use this one on the right rail. On the left there is no enought space, only fits MGN12C.
• Added Left_Rail_Holder.zip.amf file with custom support enforcer.

2019/08/20:

Minor fix: corrected the distance between holes to attach the heatbed, it was 19.5mm and must be 20mm

2020/09/22:

• Added new Carriage Blocks with Threaded Insert holes.

2022/03/14:

• Minor fix: corrected the distance between holes to attach the rail blocks, it was 19.5mm and must be 20mm
• Replaced Left_Rail_Holder.zip.amf file with Left_Rail_Holder.3mf file with custom supports