Another dry Box solution

thingiverse

There are already many dry box solutions here and somewhere else in the internet. Like many others I also had the problem with humid PETG. My basement/workshop is an average of 18 C and 50-60 % rel. humidity. I was looking for a solution for my 1 kg spools to keep my filaments dry during printing and storage. As small as possible and easy to use. This design can be hung directly on the printer. So changing filament is as fast and easy as hanging another spool of filament on the printer. (Designed for Prusa MK3S+ printer, not tested with other models. Please give feedback) Drying (better said: keeping it dry) is done by silica-gel packet(s) that you can put in the box. The box is as airtight as possible without rubber gaskets. I use the silica-gel packets that come with each spool of filament. I also recycle/reuse these silica-gel packets by drying them in the oven. For long(er) time storage I use vacuum bags with silica-gel and a humidity indicator from  E-Sun (can be found in the internet. i.e. here: esun-eVacuum-kit ). >>Printing: I printed the box with PETG but other materials should be possible (No heating inside this box, so temperature should not be an issue). I used in Prusaslicer the standard settings for the PETG Infil 15% 0.2 mm layer for best results . I added also code files for 0.3 layer. However that could give some difficulty with the central thread. This thread is not perfectly designed. No supports. Brim optional, but on the Prusa MKS+ there is not much space available for a decent brim. I had no problem with warping of the PETG on a textured Prusa build plate. For those with a bigger build plate I have added the STL's for the complete bottom and top. >>Assembly: After printing you have to glue the top left and right as well as the bottom left and right parts together. To align the parts there are small holes where you can fit in a small piece (approx 3mm long) of filament. Maybe you have to ream these holes with a 1.8 mm drill first. Put glue on all matching surfaces to make it as airtight as possible. I used CA to glue the parts together. Make sure that you do not glue your fingers to the box!. This will make ugly stains :-) The bottom part and the lid (top part) screw together. Use a small piece of OD4/ID2 mm PTFE tube to guide the filament. This will reduce wear and friction. Maybe you have to ream the hole first with a 4 mm drill and glue it in. Glue a piece of transparent plastic sheet behind the “peeping hole”. This enables you to guess how much filament there is still on the spool. >>Use: Thread the filament through the PTFE tube. Put the spool in the box so that the filament can easily unwind from the spool. Put one or more bags of silica-gel in the corner. Make sure the packet(s) of silica-gel do not interfere with the spool. It is best to secure it with a piece of tape. Close the the box. Hang the holder with the spool on the printer. Pull out a reasonable piece of filament to get to a fresh and dry filament from the inside of the box. You could place a humidity indicator behind the peeping hole. When not on the printer, the box can stored vertically, or lying flat, as long as the silica-gel is secured. Please share your results, and suggestions for improvement.