I really like emmett's Minimalistic Mk8 replacement, but I found that the idler tended to fail under pressure after a couple of months, and fitting the spring in was pretty difficult sometimes. So, for this I gave the idler more support and made the spring stays a bit rounder. While I was at it I also simplified the bearing mount's support to make it easier to clean out.

Print Settings

Printer Brand:

MakerBot

Printer:

Rafts:

Doesn't Matter

Supports:

Resolution:

.1mm

Infill:

Post-Printing

Per the original:

You'll need a 693 or 623 bearing and a 3x10mm bolt for each extruder. Print these at 100% infill with zero extra shells. Rip the support out of the notch in the arm. Put the bearing in there and keep in place by screwing in the bolt (from the back, as in the head will face the motor).

Disassemble the fan/heatsink and remove the old extruder. Use the same mounting bolts to attach the two pieces of the minimal Mk8 extruder. Make it nice and tight and reassemble the fan and heatsink the same way. Cram a spring into the notches between the two arms. I used the same spring I used on the original minimal Mk7, which in my case was Utility Comp Spring C-614 (5/16 x 1-1/4 x 0.041 inches) I found at my local hardware store.

I find it easier to insert the spring if you remove the drive gear first.

Category: 3D Printer Extruders