These sticks has been leading to some debate with some, whether this was smart or not, and honestly… I don’t care… 😛
The sticks are made to slide into the slots in the 20×20 extrusions an MM2 is made of. Inside there are room for 4 wires, 6 if you are good, and that will allow you to hide the wires going up to the Z motors.
At the bottom there is a similar hole as in the top where the wires go out again.
One plate is enough for one side, and you will then have two extra parts. Those two extra is because the risk of the small taps breaking or otherwise having defects, so one to throw out…
When I printed mine I used Slic3r 0.9.10b, 0.25mm layer height, 30mm/s perimeter, 0% fill, 1 perimeter loop, 0 solid bottom layers, 0 solid top layers
Two of the sticks on the plate are 3mm taller than all the other parts, they are needed for the top, and are those 3mm taller to make sure there are enough room for the wires to be able to go in, just under the Z motors.
At the bottom of the extrusions the wire come out again, and needs to be routed somewhere else.
Instead of going directly down to the board (the one that can be seen a bit in the left of the picture), I am going away from it instead. This is so the wires from both sides can meet in the back of the printer, and so that no wires will hang across mid air.
At the back the connectors from both motors will be cut off, and instead connected to the special connector that came with my Rumba board. This connector got two pair of wires going out instead of one.
The parts for hiding this cable is the same as the ones going vertical, instead you need to print 3 pieces cut down to a length of 38mm.