Original Prusa i3 MK3S [page 3]

One of the screws that holds the heated bed strain relief housing sticks up above the housing. Some have reported that the screw can catch on the wiring to the hot end when the printer is first being calibrated. Mine wouldn’t have (I checked), but I still didn’t see a need for the end of the screw to stick up where I’d probably catch a knuckle when not paying attention. I replaced the stock 10 mm screw with one only 8mm long.

The power supply and case for the control board are mounted on opposite sides of the frame. The first cable to attach to the ‘Einsy’ control board is the wiring from the X-axis stepper.

With the printer laying on its side I followed the instructions to route the rest of the wiring from the steppers, heaters, sensors, and LCD unit under the unit. All cable ties were cut flush using a pair of flush cutting nippers. The tool provided with the kit would have left knife edged ends sticking out.

The wiring was not difficult providing you’ve got enough light to see dark connectors inside of a dark case. The flashlight on my phone helped a couple of times. When everything is connected there is still a mass of wiring. It can be gently wadded up and stuffed inside the case.

It’s together. I cleaned up my work area and carried the printer into my office for final calibration and first power on. The built in self tests failed when testing the Y-axis. The drive belt was too loose. Once I fixed that all tests passed. The time I spent getting the frame flat and true payed off. The machine did not detect anyt X-Y skew.

It took several test prints to get the Z offset dialed in. The offset accounts for the difference between where the sensor says the Z-axis is at home and the actual location of the print nozzle. On my machine -0.800 mm gives me a good first layer.