Side-mounted Spool Holder for the Original Prusa i3 MK2

prusaprinters

<p>I really disliked the original two-piece spool holder on the Original Prusa i3 MK2 and after printing a slightly different design (with a filament guide), I decided that mounting the spool on the top of the frame just didn't sit right with me. The PSU is a metal box with reasonably thick material, screwed into both the base and the upright frame of the printer, so I decided to use that as my mounting point.</p><p>The way of fastening the mount "plates" I used isn't ideal, as it's quite fiddly to apply, but it holds fine for a 1 Kg spool without any doubts. You just have to be careful to not lose any of the H-shaped Pegs inside the PSU while you're putting the mount plates into place.</p><p><strong>Note:</strong> Before printing this, please check that the PSU looks the same as the one in the pictures. The spool holder uses the cooling cutouts in the PSU for mounting and I'm not sure if all MK2s have the same PSU.</p><h3>Print Notes</h3><p>Supports are needed only for the main Support and the Spindle, at least in the orientation I printed them in (largest dimension = Z axis). It's not too much material and they are easy to remove as well.</p><p>You should probably print a test for the Spindle, stop it after it reaches ~10mm height and check if the bearing fits inside, as it should. My printer is quite well calibrated (through no effort on my part) and the bearings barely fit. You should probably tweak either your printer settings or the model, which should be easy to do with the STEP files.</p><h3><strong>Vitamins</strong></h3><ul><li>2x 625 bearing (16mm OD, 5mm ID, 5mm height)</li><li>3x M3x10mm screw (hex heads are best)</li><li>3x M3 nut</li><li>1x 125mm long M5 threaded rod</li><li>2x M5 nut</li></ul><h3><strong>Tools</strong></h3><ul><li>Needlenose pliers</li><li>Whatever screwdriver matches your chosen M3 screws</li></ul><h3><strong>Assembly &amp; Mounting</strong></h3><ol><li>Print everything:<ul><li>1x Support</li><li>1x Spindle</li><li>1x Upper Mount</li><li>1x Lower Mount</li><li>4x Peg</li><li>2x Spacer</li></ul></li><li>Put nuts into the Upper and Lower Mount prints</li><li>Install bearings in both ends of the Spindle</li><li>Thread all the spindle parts onto the M5 threaded rod in this order<ul><li>The base of the Support (the large, triangular part)</li><li>A Spacer</li><li>The Spindle (with the bearings installed)</li><li>Another Spacer (this might be a bit tricky, I recommend using the pliers to extend the reach of your fingers)</li><li>The tip of the Support</li></ul></li><li>Place the M5 nuts on both ends of the threaded rod, tighten with your fingers. You really don't need any more force than that.</li><li>Install the Upper Mount on the PSU. Align the two slots with the topmost cutout in the PSU, the pins should help. Make sure the semicircular cutout in the printed part is on the bottom and the M3 nuts are sandwiched between the plastic and the PSU.&nbsp;<br><br>Take a Peg, hold the (slightly) taller end in your pliers, insert it into one of the slots and turn it 90 degrees - it should hold itself in place. Repeat with the other Peg.</li><li>Install the Lower Mount in the tenth cutout on the PSU the same way as you did the Upper Mount. You should then have eight free cutouts between the Upper and Lower mounts.</li><li>Screw the assembled Support piece into the Mounts</li></ol><p>You now have a shiny new spool holder!</p><h3><strong>The Filament Guide</strong></h3><p>Along with this spool holder, I also added a reverse bowden tube mounting point to one of the printed parts of the Prusa MK2 to serve as a filament guide. You can see it in the third picture and the model and instructions are <a href="https://www.printables.com/model/210175">here</a>.</p>