Improved Spool Holder for the Original Prusa i3 MK2

thingiverse

If you have an Original Prusa i3 MK2 like mine, you'll love it without a doubt. However, in my opinion, the spool holder is not up to par at all - it's tough to adjust and set up. So I've decided to create one myself that can accommodate any type of spools and changing filament has never been easier. In the folder you'll download, I've included some typical CAD formats so if you like, you can modify them to your needs. If you like, you can watch this video where I show how I did it: https://youtu.be/ehwsGeesCF0 (English version) P.S.: In the download file, you'll find the FEA Report so you can take a look at all the stresses and forces and see how they act on the model, as well as a PDF with the dimensions of the spool holder. UPGRADED VERSION 3.0: I've published an upgrade to this design that's a bit bigger, but since it's optimized to be printed with 0.3 mm layer height instead of 0.2 mm, the time it takes to print isn't much longer than before. By having it bigger, I've managed to reduce significantly the deflection in the arm and by optimizing the dimensions for printing with 0.3 mm layer height, it's also noticeably sturdier than before. P.S.: If you print one, I'd be delighted if you posted a photo of your print on this page. If you have any problems, just write them down in the comments and I'll try to figure them out. Print Settings: Printer Brand: Prusa Printer: Prusa Mk2 Rafts: No Supports: Yes Resolution: 0.3 mm for the UPGRADED (3.0) version, 0.2 mm for the OLDER (2.0) version Infill: Not less than 20% Notes: With these settings: Print time: 4h Filament length: 33615.7 mm or 33.6157 m Plastic weight: 101.07g NOTICE: It's possible to print it with no support material whatsoever since the overhang is very small, but that may result in a not great quality on the final part of the arm. If you choose to print it without support, I recommend filing down with some sandpaper the rough part left by the printer where the overhang is. It doesn't have to be pretty since this is mostly a functional print. PS: The STL file should already be positioned in order to minimize the support material. My advice is not to change the orientation of the STL file once imported into the slicer. How I Designed This: I've designed it in Autodesk Fusion 360. I went through some design changes, but this one's really great because it's optimized with a lot of FEA studies. Just to give you an idea, I applied 20N of force on the arm (twice the force it has to overcome since a typical spool weighs around 10N or 1Kg) and it was still showing a minimum safety factor of 11.38, so you can be absolutely sure that with 1 kg spool it will never break and it doesn't require a ton of plastic to print. It's a really simple design with just four extrusions and a lot of fillets. In the zip file you'll download, you'll find the CAD model so you can modify it if you like. Complete assembly in Fusion 360: Here you can see the stresses acting on the model. If you're interested, check out the "Study_Report_Spool_holder_3.0_UPGRADED.html" in the files you'll download for a complete FEA study. Review of this project