Ender 3 - compact Hemera mount plate with BLTouch

Compact mount plate for mounting the Hemera Extruder to an Ender-3 carriage.

I initially mounted my Hemera Extruder using [Joe Cashas mount plate](https://myminifactory.com/object/3d-print-ender-3-e3d-hemera-mount-105802), but found it a bit to wobbly because the motor part was placed to the right of the Ender mount plate and only fastened in three places. So I designed this instead. Tolerances are quite tight so your printer needs to be dialed in well.

Besides the stock parts, you need 4 M3x6 bolts and 4 M5 washers.

Instructions:

* Take apart the existing hotend and x carriage. Remove the three wheels from the carriage.
* Add the 3 M5 nylock bolts to the matching holes on the plate.
* Mount the Hemera to the plate using the M3x6 bolts
* Press the metal carriage into the two holes on the mount plate.
* Prepare the three bolts:
Add two washers, a wheel and a metal spacer to each of the two bolts for the top wheels.
Add the original washer, a wheel and the eccentric