Improved and simplified "Over the Top" Carriage for BMG, V6/Volcano, BLTouch & RJ45 breakout

thingiverse

This is a sturdy, compact, and lightweight carriage arrangement for a BMG extruder and other common accessories (like a BLTouch and a dual RJ-45 adapter so that CAT6 cables can be easily connected to the components on the carriage). It is based on my previous design found at https://www.thingiverse.com/thing:3615464 . I created this improved version because I used PETG to print the previous one, and the PETG "plate" part had too much flex for my liking. This new design adds upper walls for excellent vertical stiffening even with less-stiff filaments. By doing so, it also allows the dual RJ45 breakout board mounting to be integrated into the other parts, reducing the number of printed parts and simplifying printing and assembly. The design, created for a FT-5 printer, features the carriage mounted on an MG12H slider and horizontal 2020 extruded bar, with the extruder and motor positioned above those pieces. Several other printers use a similar MG12H slider and 2020 arrangement (FT-6, and some others), so this design should be adaptable to those as well. Also included are textured clamps that securely hold 2mm belts instead of using tie-wraps. The clamps enable belts to be removed and reinstalled without needing a new belt. The RJ45 breakout board is available from Amazon (using the MDFLY dual RJ45 board w/screw terminals): https://www.amazon.com/gp/product/B01KHMFH1M/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1 . It can be left off if desired. The "Over the Top" placement of the extruder provides better stability since the nozzle sits closer to the linear bearing, resulting in less movement. However, this may cause an issue with some printers (like the FT-5) as it moves the nozzle up so high that the bed cannot reach it. For the FT-5, the bed needs to be raised about 48mm from the melamine bed platform with standard V6, or about 40mm with a Volcano. This can be easily achieved with some pieces of wood or using this neat 3D printed bed riser: https://www.thingiverse.com/thing:3719437 . **Some related designs used with this arrangement: (partially shown in the photos)** + **Part cooling and heatsink fan for V6 hot end:** https://www.thingiverse.com/thing:3687678 + **"Cable danglers"** (so those in-the-way cable chains of the FT-5 can be removed): https://www.thingiverse.com/thing:3613175 + **Spiral cable Strain Reliefs:** https://www.thingiverse.com/thing:3624481 + **Bed Riser:** https://www.thingiverse.com/thing:3719437