PowerSpec Ultra SKR Upgrade

thingiverse

Here is a rewritten version of the text in a more readable format: **Hardware Notes** * The following changes were made: + Thermocouples were replaced with thermistors, which required different heater blocks. Note that the grub screw on the stock heater block is M4 and on the bottom, so it wouldn't work for an M3 thermistor. + The hole for the heater cartridge had to be widened with a 1/4" drill bit due to the new heater blocks. + One of the heater blocks was upside down, so make sure to screw in the grub screw for the one that would be blocked by the cooling bar assembly. * Additional notes: + Consider using an M3 thermistor instead of the grub screw on the stock heater block. However, this may not work due to the M4 thread and location of the grub screw. + If you don't want to change the heater blocks, consider using a thermistor connector with an M4 thread: https://www.ebay.com/itm/M3-M4-Thermistor-Hot-End-Screw-Type-Thermistors-For-3D-Printe/392200661436 * Wiring notes: + Heated bed thermistor wiring is white (signal), green (ground), yellow (ground), blue (5V). Use white/green. + End-stops are red, black, green, black. Use red/black for signal/ground. + EX1/EX2 on the FlashForge board are green (ground), orange (24V), black (ground), red (24V). Use green/orange for heater cartridge and red/black for hotend fan + Motherboard cooling fan's positive/negative on the 2-pin JST were wired backwards from what the SKR uses. Same goes for the orange/green JST connector for the part cooling fan. * Other notes: + Set MAX_BED_POWER to 215 in Marlin to prevent bed heating failure due to underpowered PSU/low resistance bed. Consider upgrading to a 450W or higher power supply and using a MOSFET. + Invert the direction on the right extruder in Marlin if necessary. Also, invert the red/yellow wires on the stepper motors on X/Y/Z if you previously swapped them for hardware inversion. **Pi Mount** * The Pi mount design "pi_mount.stl" allows mounting of a Raspberry Pi (tested with 3B), LM2596 buck converter, and 4 channel relay board. * The bracket lets the Pi's network port sit flush against the cutout for the USB Type-B port. The Pi's USB ports are blocked, but use GPIO pins to connect to the SKR board and wire the buck converter to test pads on the bottom of the Pi for power. * Cut out the side of the case with a Dremel or use the bracket as a reference for your own design if you need access to all of the ports on the Pi. **Updated Files** * Added "PowerSpec_Ultra_pi_mount_v2.stl" which should fit the 4 channel relay properly (65mm x 45mm mounting holes). * Added "5mm_Standoff_for_Relay_Module.stl" to lift the relay board away from the screws that hold in the bracket.