KKm extruder (only bearing) for bearings (with 3 or 4 mm inner diametr ) and other improvements

I have now made over 30 extruders and am sharing my experience. It lets to fix two problems: bad clamping and overheating.

Suitable for printers:  k1 series

This version uses: 2 pins instead of 3 a through hole has been added for better pin retention the pin has been replaced with a screw, making it easier to disassemble the extruder if necessary the foot design has been slightly modified so that it does not catch on the screw.

You will need (all versions): 

• The pinion gear (or buy a metal pinion gear) and bearing from the stock extruder 
• 1x ECAS04 fitting
• 1x M3 washers 
• 1x M3x18 wing screw 
• 1x tension spring (recommended: diameter - 1 mm, outer diameter - 6 mm, height 12 mm) 
• 3x M3x20 DIN 965 (countersunk head screw) 
• 1x M3x24 DIN 965 (countersunk head screw) - this screw is needed to ensure the motor screws are the same length, but you can use an M3*20 screw instead 
• 6x M3 heat inserts (4.5mm outer diameter, 4mm length) 
• 1х bearing MR63 3X6X2.5 (сan be used from a stock extruder) 
• 2x M3 nuts (you can use a regular one if you frequently remove the extruder or you can use one with a nylon insert) 

And for 4 mm version: 

• 2x 4x15mm pins 
• 4x MR84ZZ 4X8X3 bearings  (NOTE: You may only need 2 bearings; some gears are different—some require 2 bearings, while others only require 1)

And for 3 mm version: 

• 2x 3x15mm pins 
• 4x MR83ZZ 3X8X3 bearings (NOTE: You will most likely need 2 bearings; Triangle-lab designed the new version of gear so that it currently only accepts 1 bearing; I don't know about other manufacturers)

Printing: 

• ABS-CF, PP-GF30, PA-GF30, or better recommended 
• Infill: 100% 
• Layer Height: 0.12 
• Top and bottom shell layers: 4 
• Wall loops: 4

Support: tree manual

I highly recommend printing this part in PP-GF30 or PA-GF30, as the bushing shown in the picture, made of weaker plastic, can break during use (I've had such cases, and I personally print this part in PP-GF30). 

I print the remaining parts in ABS-CF. Since PP-GF30 is printed slightly differently, this part is available with bushing sizes of 4 mm and 3.8 mm (you'll understand from the file name). Select the desired file.

M3x24 (may M3x20)

I hope you will enjoy

Currently, the triangle-lab (and others) gears come with a 3mm inner diameter, which necessitated a model change. Improvements based on the 30+ extruders built have also been added.