Samje 3D Printer Bulldog Extruder Wire Feeder All Metal DIY Extruder Kit for 1.75mm J-head MK8 Reprap

I installed this onto a CR10.,The idea was get the filament away from the lead screw and to get rid of the standard plastic version. It fits together quite nicely and looks the part. The springs are a bit tricky to intsall, and the tension is crazy, in some ways overkill..Remember you will have to reverse your motor and re-calibrate the extruder.Now to the negatives - Guiding the filament in can be a serious pain - No build instructions, which would help when fitting the bearing. so its springs first, then bearing. it will give you a little extra room when fitting the springs. - When printing there is quite a loud click. this is under retraction. The main tensioner moves side when retracting. but it doesnt do it all the time. so getting your retraction settings spot on is impossible. The space between the housing and bearing holder is to big allowing for play, which i can only put down to poor manufacturing. For this reason i have removed it, and wont be using it. Positives - Looks the part. - better fittings to secure the ptfe tube.personally i would avoid this one and look into something else.

I like how tight this grips the filament. the smooth pulley is a bit of a shame, but in all honesty it works very well. Beware - its all metal, so if your extruder stepper gets hot to the touch this will cause filament to start snagging in the extruder! I had to drop Vref on extruder stepper down to around 0.5/6v. Now runs perfect. Is a bit clicky, but its like a confirmation of retraction!