I used the following MK8 Drive Gear, mounted upside down to fit well:http://www.aliexpress.com/item/3D-Printer-accessory-MK8-Driver-gear/32221820601.html
Sorry, I wanted to mention about the bearing axle (not the stepper axle which is fine).
Since they are 20 mm as well, they should be flushed with the extruder body unless you didn't insert them fully.
About loading, the first time is a little tricky as the nuts have to find they correct place, but once this is done, it's quick enough (remember just to open it like a clam to proceed).
Ah, now I understand what you meant! For mockup, I did not pushed them in completely and the bottom part was very roughly printed
I printed the pins together with the rest, with too high printspeed to get a nice finish.
The (very rough) part that sticks out was the bottom part of the print. When the other items on the bed reach their final height the print was slowed down for the pins to get more time to cool. The top part of the pins was so smooth, they just glided in their space on the extruder.
For mockup, I did not push them in completely (or smoothed the rough part of the pins first).
Great! Thanks for the feedback and hope i helps others to try this solution.
Are you having issues with your former extruder? The lower surface on the first photo seems to be a little under-extruded...
Also, you may want to reduce the current to your 2.5A stepper (by turning down the potentiometer on the RAMPS) and avoid overheating.
Report any progress and/or gripe with this solution.
The motor axle should go flush with the upper surface. Any reason why not?
Correct, I had some issues the first couple of layers with my extruder (z-height to close to bed). Just left it printing after I found out, so I could dry fit your MK8 version first and report backt to you, before testing.
I will print a new version when I am ready to test.
I am currently using a 5:1 geared stepper for the extruder on my KosselXL on DRV8825 driver (1/32-step).
The stepper motor in the picture I had laying around for a new SmartrapCore build I am preparing, the Saintflint extruder(s) will be used in there. I will keep an eye on the voltage for the stepper, I know they are a little high on Amp.
The 5mm axle has a length of 22mm measured from where it sticks out of the stepper housing. The extruder itself is mounted flush to the stepper housing (without any washers). The arms of the extruder are 20mm heigh, that leaves the 2mm sticking out.
But it is possible I will use it on the KosselXl as well, if all goes well.
I really like this design, although changing filament will be getting used to...