PanelDue 7i enclosure for printing on small print-beds (OpenSCAD)

thingiverse

<h3>Introduction</h3> I recently purchased a PanelDue 7i for my CoreXY printer as I wanted to be able to use that machine independently of my computer. I thought the 7" screen would be most useful, not realising that I wouldn't be able to print an enclosure on either of my printers! The CoreXY has a 200mm x 200mm bed, and my Anycubic Kossel has a 240mm round bed - typical enclosures are all a little too large for either printer. This meant that I had to get creative... <h3>Basics of the design</h3> I used OpenSCAD to design a complete enclosure that could be printed in 2 halves and glued together later (although the enclosure can be printed in one piece if your print-bed is big enough). I designed it with the expectation that I would have to glue the pieces together, fill the gaps and paint the enclosure to get the finish I wanted. <h3>Printing setup</h3> The first step is to print the test jig and see if it matches the holes in the PanelDue circuit board. It will, if your printer is accurate, but otherwise you will have to use scaling in the slicer. Once you are certain that the holes in the jig and PCB line up perfectly you can start to print the enclosure (using the same scaling factors if required). Retain the correct-sized test jig as it will be used later during the gluing process. The pieces can be printed in one session if the unbraced halves are slotted together in the slicer; however, I found that the open ends of each half tended to distort on cooling and set into positions that are difficult to glue together. Because of this I would recommend printing the braced versions, although they can only be done one at a time. The braces are only lightly fixed in place and easy to remove at the appropriate time - in fact, you should take care not to dislodge them until you are ready. I used a pair of internal joining pieces to fix the 2 halves together as I wanted a smooth exterior. I have also included an STL file for external joiners, but they are untested - they may prove difficult to print nicely. You could use both inside and outside joiners if you really want a strong case! <i>Note: the inside joiner shown in the photographs was originally L-shaped - after assembly I found that the bottom fouled the side of the LCD screen and I had to cut it away, so now the joiner is a simple flat plate. This will still be more than strong enough if assembled and glued properly. </i> <h3>Assembly</h3> Both halves were located using the jig printed earlier, and the ends clamped to a piece of 20mm aluminium angle extrusion to ensure that their sides and top were perfectly aligned. The joiner was clamped over the joint, ensuring that all faces fitted snugly together. If you're using outside joiners then you will have to fit the aluminium extrusion to the inside of the joint and clamp accordingly. Liquid "plastic weld" was then painted generously over every seam and the joint left to harden. Once set, the aluminium extrusion was taken off and more plastic weld painted over the other side of each joint. The second side was done once the first side had set hard. At this point the jig was removed and the PCB fitted to check that everything was OK. <h3>Finishing</h3> Any gaps remaining after joining were filled with automotive body filler, then sanded flat. After a general check for lumps and bumps the enclosure was sprayed first with plastic primer, then with a coat of black gloss. This was left to fully dry off, then the PanelDue PCB was fitted properly, using M3 x 16mm screws. I used nylon washers under the nuts, but I'm not sure that was really necessary. <h3>Mounting the enclosure</h3> The case has a pair of holes at each end so that M3 screws can be used to fix it to brackets. Make sure that the screws do not contact the PCB - there's about enough clearance for the M3 nut and a tiny bit more. I have included the OpenSCAD file <i>"PanelDue_mount.scad"</i> as a reference for anyone who wishes to design their own brackets, but I didn't include STL files as they were created specifically for my home-built printer and unlikely to fit anything else. Hopefully it is documented enough that others can use it as a reference for their own printer. An aluminium plate was used to close the base of the assembly and protect the PanelDue board.