Is it a build for me?
I really love the simple design of the MicroCube and I was looking for a more relieable movement system. I found the HyperCube Evolution to be a loved and very successful design, so I tried to get the best of both worlds. This printer is a case study and was not designed for low cost or high precision. It is a proof of concept. I believe this design is not ideal for a beginner, please have a look at the original MicroCube printer if you want something cheap and simple to start your adventure.
How does it print?
After some tweaking and the addition of two diagonal rods to stabilize the frame it prints really nicely. I was able to print the silver fire truck at 100% scale and made all parts move! (https://www.thingiverse.com/thing:2805211) I also moved the Y endswitch to another location and changed X and Y to maximum limit switches (X+ and Y+). You can also find a video of a 50% scale benchy printed at 0.1mm layer height here https://youtu.be/8Yh10767Pzo
Speed and vibrations have still to be considered with the rods compared to an extrusion based frame. It is possible to print with 35 - 45 mm/s, I would not recommend more. The usable print area for my build is 90x90x130mm. Also cooling could probably be improved, I like the simplicity of single fan cooling shrouds and designed one to try on this machine. I went through several iterations and this is currently the best performing one. The red print in the pictures is the surprise egg #5 fire truck printed at 150% scale and 0.2mm layer height.
How to build?
I mostly used the 8mm rods, T8 leadscrew and bearings from my Wanhao Duplicator i3 mini (rest in peace...) for the hardware and 3x Nema11 to see if it was possible to drive a GT2 belt based printer. It is! Used a trusty Nema17 for the extruder though, never had any problems with it. Also using TMC2208 drivers in standalone mode on a MKS Gen L 1.0 board. You can also use A4988 drivers with a Ramps 1.4 sandwich, have a look at the original MicroCube (https://www.thingiverse.com/thing:1938877) for a mount.
I'm driving the little Nema11 with 450mV Vref for X, Y and Z. The Nema17 is driven with 850mV Vref. The Nema11 get up to 42 degree celcius which is acceptable. Also cooling the MKS board with a 60mm fan to catch the drivers.
Using the Mech Endstop 1.2 designed by MakerBot for all 3 axis and designed mounts for all of them. I'm also using M3 screws of various lengths for (almost) everything, the Nema11 motors are mounted with M2.5 screws... The rod lenghts can be varied greatly, I suggest using rods with 250mm for x/y and 300mm for z. The diagonal rods are 305mm. The hotend is a cheap chinese 12V E3D clone.
I don't plan to write a build guide, this is basically a MicroCube with some parts borrowed and customized from the HyperCube Evolution which both have excellent guides. I included the scad files for my own designs / modifications aswell as a copy of my configuration for the marlin firmware (1.1.9).
I would love to see someone improving this design or get inspired to build their own! Please feel free to write a comment if you have any questions, I tried to take pictures of all critical areas.