Darren Faulke

Make sure that one of the grub screws is over the flat portion of the motor shaft and tighten just enough that it doesn’t run onto the curved part if the shaft is rotated. At the tightening stage, failure to tighten the grub screw over this region will cause the pulley to slip leading to axis shifts in the print.

There is no guide for cable routing, which is a shame because there are slots for zip ties in some of the pieces so there was obviously a design intent for how the wiring was meant to be done. I separated the wires into 2 bundles - 1: everything from the hot end (thermistor, heater, x end-stop, hot-end cooling fan, part cooling fan, extruder motor, probe), and the rest - 2: (y end-stop, bed heater, bed thermistor, x motor, y motor, z motor).

I wound the flexible conduit around around 5 cm (2”) of the hot end cables but keeping some loops in the cables, then using 4 cable ties to strap it to the Cartesian cable-fin (section 07, step 5). I then passed everything through the case duct and plugged everything into the motherboard; Bundle 2 first since these have the largest connectors! I then went through the RatOS installation and did some homing tests to make sure the motors, end-stops and inductance probe worked. The final step is to wind the rest of the cables into the conduit and tidy up before heater tests.

The wiring is fairly straightforward but I had trouble with the inductive probe. I had a Heschen LJ8A3-2-Z/AX in my kit (https://heschen.com/products/lj8a3-2-z-a...) but it has an orange tip. The wiring already had crimped JST pins but no body. Using the reference image (https://github.com/bigtreetech/SKR-2/blo...) the appropriate fpins are SERVOS +5V, and PROBE GND & PE4. The red wire goes to the SERVOS +5V, the blue to the GND and black to PE4. I thought it more intuitive with the black and blue swapped but this didn’t work for me. I used a JST-XH connector kit and used a XH-3Y for the red (PROBE +5V), and a XH-2Y for the blue and black (PROBE).

There is a significant gap between the top of the leadscrew and the z-cap that is counter-intuitive.

The wires are held in place by zip ties that pass through the bed wire guide attached in step 7. It is counter-intuitive to have the cables effectively leaving the plate at the front but this component allows the wires to be looped round and restrained. The cable tie slots are toward the upper-left in the image above.