After the mechanics seemed to work I invested into the CNC parts: NEMA17 (42mm) stepper motors and a motion controller. The three pulleys did fit (the fourth motor is assigned to drive the feeder later).
As usual the (vulnerable) stepper motor drivers are detacheable, so they can be swapped if damaged.
Unfortunately neither ErikZalm (Marlin) nor jcrocholl (Rostock and Kossel printers) used a Sanguinololu – so I got a whole bunch of errors, until I eventually updated the “Sanguino”-folder of the Arduino-IDE.
Then, finally the stepper drivers tried to home the axes:
This is “bootsrapping“, so zip-tying the motors in place is justified. And also this kind of “custom moulded limit switch mount”. 😉
The idlers consist of bent bars, washers, a screw and a ball bearing each.
Here is the good thing about Delta printers: Repeat one axis three times:
This fan is a measure of precaution. I burned my fingers more than once when touching the stepper drivers.
In the meantime I finally met someone with an already working Prusa i3 at the tavern. And he assisted me by printing the feeder mechanism: Airtripper’s Bowden Extruder V3. As I ordered my J-Head MK-V HotEnd before the Filament Drive Gear Review & Benchmark was written, it came along with the MK7 drive gear.
By now I would choose none of them.
This is the assembly of the feeder:
The J-Head mounting plate was cut with a belt saw (you could even Dremel it). The hot end cooling fan is attached to the effector via hotmelt.
Feeding the first piece of 1.75mm PLA towards the hot end:
…and there it is, extruded to 0.35mm: