Dry Box and External Spool Hanger for Qidi Printers

prusaprinters

<p><strong>DESIGN INSPIRATION</strong></p><p>The Qidi X-CF Pro printer comes with a dry box for hydroscopic filaments such as Nylon. Unfortunately the dry box mounting system provided by Qidi requires at least 350mm of additional space behind the printer. The result is the printer will not fit on a typical 25" to 30" (635mm - 762mm) deep desktop. Loading spools and threading filament with the Qidi solution is also a frustrating experience.</p><p><strong>DESIGN REQUIREMENTS</strong></p><p>The total depth of the printer and mounted dry box cannot exceed 25 inches (635mm)<br>The dry box has to be an integral part of the printer, i.e., move with the printer and not rely on a wall, shelf, desktop support, etc.</p><ul><li>The PFTE connecting tube from the dry box to the printer must provide a smooth path for the filament</li><li>The filament must be easy to thread</li><li>The dry box cannot interfere with printer access</li><li>It must be simple to print</li><li>It must be easy to install</li><li>It must work with common dry box designs</li><li>It must provide the option to install a second dry box (or spool holder)</li><li>It must be strong enough to securely hold a full 1kg roll of filament</li><li>It must allow access for installing the dry box's sealing band</li><li>It should be compatible with X-Max, X-Plus and other Qidi printers with the popup (suitcase) spool holder</li></ul><p>The final design allows for mounting a Filament Dry Box on one of the popup spool holders built into many Qidi printers. It also allows enough space to mount a second dry box or open spool holder.</p><p>If the open spool holder is used, a filament guide is needed to keep the filament on the spool. There are two options. The first mounts on the spool hanger and the other uses a filament guide with 4mm x 2mm PFTE tubing and slips on to an upgraded Filament Runout Sensor case: <a href="https://www.prusaprinters.org/prints/140361-qidi-x-cf-pro-filament-sensor-case-easy-to-use">https://www.prusaprinters.org/prints/140361-qidi-x-cf-pro-filament-sensor-case-easy-to-use</a></p><p>The dry box is attached to the hanger with M3 screws and the entire assembly simply hangs from the existing suitcase spool holder. It has an adjustable alignment plate to keep it from moving around. It can easily be lifted off for changing and loading filament.</p><p><strong>PRINTING</strong></p><p>I recommend printing with reinforced polycarbonate or Nylon filament, but an enhanced PLA works well. I used 25% gyroid infill. Supports are required for the mounting bar. I set supports for everywhere, 15% zigzag and 55 degrees.</p><p>The Spool and Base is designed as a print in place bearing. Printing guidance is available here: <a href="https://www.prusaprinters.org/prints/155518-qidi-x-max-x-plus-internal-spool-holder">https://www.prusaprinters.org/prints/155518-qidi-x-max-x-plus-internal-spool-holder</a></p><p>The Spool Filament Guide is also designed as a print in place bearing. Elephant's Foot may cause the bottom of the post to fuse with the arm. Sanding away a few tenths of a millimeter should release the post.</p><p>Both the Spool and the guide will benefit from making sure your flow is adjusted correctly. Hume Beam (humebeam when searching PRUSA) has flow calibration cubes here: <a href="https://www.prusaprinters.org/prints/81314-flow-calibration-cube">https://www.prusaprinters.org/prints/81314-flow-calibration-cube</a></p><p><strong>POST PRINTING</strong></p><p>A modest modification of drilling four 4mm mounting holes in the side of the dry box is required. When drilling the holes make sure to avoid internal structures such as the bearing bosses.</p><p>You will need four M3 threaded brass inserts and associated M3-12mm bolts (long enough to pass through the dry box case, spacers and inserts).</p><p>I recommend locating the hanger off center towards the front of the dry box (see photos). This position allows for a smoothly curved PTFE tube from the front of the box to the filament sensor (black PTFE filament tube on X-Max and X-Plus printers). It also allows for mounting a second dry box on the other side.</p><p>While not required, I highly recommend relocating the PTFE fitting from the lid to the lower half of the box. This requires drilling an 8mm hole on the front of the box about 40mm from the bottom. A small plug is inserted into the fitting opening in the lid to keep it air tight. The lower position avoids the frustration associated with threading the filament through the lid which often causes the filament to jump off the spool when closing the lid.</p><p><strong>USING</strong></p><p>The filament flow off of the spool can cause the spool cap to unscrew. If the Spool is mounted on the Right, the flow should be off the top of the spool. If the spool is mounted on the Left, the flow should be off the bottom of the spool. The Dry Box can be mounted on either the left or the right.</p><p>&nbsp;</p>