Prusa i3 MK2 Spool Holder

thingiverse

I absolutely loved the standard spool holders that came with the Prusa i3 MK2 so decided to spice up the functionality and make it a bit more aesthetically pleasing with a crossbar to hold the filament. All spool sizes should be compatible. I wanted to test regular nuts while printing so the arms connect to the cylinders via embedded M3 nuts and secured using 15mm M3 bolts. I've provided a guide on how to pause the print to remove the nuts. I've also provided a combined .stl for those that want to use hardware. Print Settings Printer: Prusa i3 MK2 Rafts: Yes Resolution: 0.2mm Infill: 40-60% Skills Learned Pausing prints Printing with M3 Hardware Adding a pause to the gcode You need to remove the M3 screws while it's printing so this requires a pause to be placed into the .gcode. I use Simplify3D and this can be done in the scripts tab of the process options. Using 0.2mm z-resolution we want to pause at around layer 29 to insert the nut, so the script to use: {REPLACE "; layer 29, Z = " "; layer 29 G1 X190.000000 Y5.000000 M25 M17 G1 X190.000000 Y5.000000 ; layer 29 "} This will place the following into the .gcode file (I've commented what happens but this is not in the .gocde): layer 29 //start layer 29 G1 X190.000000 Y190.000000 //Go to the back right of the bed M25 //Pause SD card print M17 //Enable the motors so we don't move the bed when getting the nuts in the holes. G1 X190.000000 Y190.000000 //I honestly don't know why this is here. If you don't have Simplify3D I am sure the other slicers can do something similar but I have no idea how, but you can do it manually in the .gcode. This is an example of what it should look like (G1 commands will be different for you so don't stress if it looks different): G1 X103.797 Y103.000 E0.0263 G1 X103.997 Y103.000 F1920 G1 E-1.5000 F1800; layer 29 G1 X190.000000 Y5.000000 M25 M17 G1 X190.000000 Y5.000000 ; layer 29 2.9 G1 E10 F50 ; inner perimeter G1 X104.541 Y120.533 F4800 G1 Z2.900 F1000 Save the .gcode file and we're almost done... Simplify3D Script Settings Adding a purge to the gcode One thing this script does is add a small amount of filament to the print bed after the pause, making it easier to resume printing. What your gcode should look like Printing Make sure the cylinders print with the hexagonal ends up the top and the arms print with the small M3 cap hole on the bottom. The cylinders need support from the build platform only and should have the supports INSIDE the M3 hole of the male part removed. The arms should have supports for the M3 cap hole on the bottom. The print will pause at layer 29 and move the back edge of the bed. Push the nuts in the holes, be sure to remove any supports in the holes and make sure the nuts do not extend outside of the holes otherwise the nozzle will hit them. Hit resume print on the LCD. The nozzle will purge a small amount and then continue to print. The next layer probably won't be very nice as it'll be bridging a solid layer but it'll fix itself up ;) Done! Inserting nuts while the print is paused Non-hardware Printing Print with the cylinders pointing up and no supports and you're good to go! Best practice for mounting the spool The way I use this is as follows: Get your spool and insert one of the arms of the holder into the spool. Put the other arm into the other side of the spool and connect the arms together. Pick up the spool + holder, keeping it all together and attach both arms to the top of the frame at the same time. Be sure the spool is hanging towards the back of the printer, otherwise the extruder can hit it.