Prusa Mk3s Extruder setup for Linear Rail MGN12H Ender 3

thingiverse

So, I wanted a direct drive extruder setup and wasn't happy with the one available, so I went ahead and designed something like my Prusa. I left out the features for the filament runout sensor since I don't use it myself. If you're not using one either, it won't cause any problems. I also took the opportunity to upgrade to a MGN12H linear rail because it was easy to add with just bolts and T nuts, and I wanted to keep the original extruder parts intact for backup. I upgraded my X-Axis to linear rail, used sensorless homing on my TMC2130, and designed this adapter plate. Going with sensorless homing was less hassle than modifying more hardware. You'll need plenty of M3 screws - I ordered a kit from Amazon but didn't note what I used. Other things you'll need: - E3D V6 hot end - MGN12H Linear rail (300mm) - Inductive sensor - Steel build plate for mesh bed levelling - Sensorless homing, or design something for the X limit switch to work - Bondtech gear - You can use the stock extruder FAN, but I use a 5V Noctua and power it with a LM296 module The extruder steps per mm are now 140steps per mm (and not 96 like the regular extruder) - make sure to update this in Marlin too. Here's a link to my CAD on Onshape: https://cad.onshape.com/documents/c8898aacdc669d63ed11febf/w/de1ac0c83b01cef0053b70af/e/fb0c02672a3931545f7354b7 The source documents were taken from GrabCAD at: https://grabcad.com/library/prusa-i3-mk3-solidworks-1 I got my inspiration from Thingiverse at: https://www.thingiverse.com/thing:3719561, but I wanted a MK3s version and mounted it on my MGN12H rail. All extruder parts are the stock Prusa ones except for the extruder body, which I changed to add three holes for better rigidity with the base. You'll also need an E3D V6 hot end and a Steel Springsheet build plate if you want to use the inductive sensor like me. Have fun! PS: I'm thinking of a version that changes the belt adapter to include a cable shroud, similar to the Prusa, which would make wire management easier. Some part references: - Thermistor: https://www.aliexpress.com/item/32847452724.html?spm=a2g0s.9042311.0.0.de144c4dsMuuyT - Heater cartridge: https://www.aliexpress.com/item/32815934251.html?spm=a2g0s.9042311.0.0.de144c4dsMuuyT - Hot end: https://www.aliexpress.com/item/32844313509.html?spm=a2g0s.9042311.0.0.de144c4dsMuuyT - Bondtech Gears: https://www.aliexpress.com/item/32907327548.html?spm=a2g0s.9042311.0.0.27424c4d6vliJs - Inductive sensor: https://www.aliexpress.com/item/33006152423.html?spm=a2g0s.9042311.0.0.de144c4dsMuuyT - Textured Steel build plate: https://www.aliexpress.com/item/33006756328.html?spm=a2g0s.9042311.0.0.de144c4dsMuuyT - MGN12H Linear Rail: https://www.amazon.ca/gp/product/B07XT8ZY9H/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&psc=1 I'm using an SKR PRO 1.1: https://www.biqu.equipment/products/bigtreetech-skr-pro-v1-1-32-bit-control-board, but anything running Marlin should work fine. I recommend using PETG at 40-50% infill - no need for supports.