PINDA cooler for Bear MK2(s)/MK2.5/MK3 Bondtech upgrade

thingiverse

The Original Prusa i3 Mk2 has one major flaw: PINDA sensitivity drifts significantly with temperature. I was able to reduce this drift down to about 0.080 mm when printing with PLA versus ABS using the PINDA cooler. It's designed to be printable without supports at a layer height of 0.20 mm. https://www.youtube.com/watch?v=BNZ8oraqeRg By adding M851 Z0.XXX; z offset to the filament gcode for ABS or PETG or any other high-temperature material, I never have to adjust live z anymore. Materials needed: • A 5015 fan running on 12-volt or 24-volt power depending on your printer. • 9/16" or 16 mm OD vinyl tubing. • A micro switch with an arm. • M3X10 mm machine screws. • Wires. • An M5x8 mm machine screw. • An M5 T nut. • Some small and short screws for the micro switch. You will need to bend the steel arm of the micro switch to make it trigger against the PINDA holder. From Universaljoints thing: "Wire the limit switch as follows: 1. The positive lead of the power supply -> Common terminal of the limit switch (C) 2. Normally open terminal of the limit switch (NO) -> Fan positive terminal 3. Fan negative terminal -> Negative lead of the power supply" Included among the files is my start and ending gcode. It does several things: • Moves the extruder to cool the PINDA for 60 seconds, which is mandatory for this to work. • Limits filament oozing during bed leveling • Levels the X gantry • Heats up the bed with the PINDA far away from the bed The important part is this: ; START OF PINDA COOLER GCODE G28 X Y Z ; Home all without mesh bed level G1 Z20 F1500 ; Raise nozzle to 20mm above the bed G1 X230 F8000 ; Rapid move to end of x carriage G1 Z1 X250 F600 ; Slowly move to limit switch G4 P15000 ; Hang out by the cooler for about 15 seconds G4 P15000 ; Some more hanging around G4 P15000 ; Just linger a bit longer because it feels cool G4 P15000 ; Dwell just a tiny bit more G1 Z20 X220 F600 ; Back off to turn off fan ; END PINDA COOLING SEQUENCE This has been tested on MK2s Bear upgrade with Bondtech upgrade. I take no responsibility for any damage caused to your machine. To test this properly for safe tolerances, start with safe numbers and iteratively work your way closer to the switch by using something like: G1 Z5 X245 F600 ; Slowly move to limit switch