I know everyone has a design for a filament dryer but here is mine.
I already had a food dehydrator that I bought at a surplus store for about $20 CDN and I wanted to use it for drying filament without destroying it's ability to be used for it's intended purpose.
This meant that all that I needed was a circular enclosure that would fit into the base and support the lid.
I have shaped cardboard into odd forms by slitting one side along the corrugations which allows you to bend the cardboard into any shape in one direction while maintaining strength in the other direction and I had an old coroplast sign that I was not going to use any more so I decided to use that like I would cardboard and I just needed something to support the top and bottom to maintain a nice clean circle.
This thing is what I came up with.
By the way, while drying my filament, I also throw in the bags of desiccant that I use to store the filament as well.
To assemble the enclosure, I slid the coroplast into the slots of the op and bottom ring segments with the seam ending up in the center of one of the segments. Once I verified that the two ends of the coroplast met nicely at the seam, I removed the top and bottom ring segments and taped the seam on the inside wall using some Gorilla tape although packing tape or any decent wide tape will do. I then reinstalled the top and bottom ring segments that I had removed.
As with all of my designs, I used SpaceClaim to design the top and bottom support for my enclosure.
I simply measured one of the drying trays from the dehydrator and created a similar profile at the bottom and top so that the enclosure would fit in the same way that a tray would.
I also built in a slot for the coroplast to fit snugly into.
I calculated the circumference of the slot which worked out to 100.5 cm and measured some filament rolls to see what I needed for height in order to fit 3 rolls which worked out to 19 cm (of course you can make yours as tall or short as you like).
Once the coroplast is cut to size, you will need to slit one side of the coroplast at every corrugation so that it will bend into a nice circle when inserted into the slot of the top and bottom rim.
In order to fit on my printer, I split the top and bottom rims into 4 quarters and added an overlapping tab so that I could glue them together but found that the gluing was not actually necessary.