Designed a Filament Dryer for 1.75mm 1 Kilogram Spools.
The Design is shaped so that a Simple Filament Roller
( https://www.thingiverse.com/thing:6732615 designed by e_grnsmnn )
can fit inside as well as Silica beads in the rear and a Mini Hygrometer in the front.
sizing required is 1.87 inches wide by 1.12 inches tall and a depth of 0.57 inches
as suppliers rotate.
Currently working on getting it just right but this seems to be a pretty stable design.
Designed to mount 20mm fan to the front left outside of base.
i would also recommend printing a TPU rim to create an airtight seal, those with multi extruders can remix this to achieve that but as i have a CR-10s Pro V2, it isn't something i have experience with.
Print the base in Black, and the Top in Transparent for designed aesthetic, will update to allow for Bowden tube to be installed in the filament exit as well.
[Updated Base to for fan. i forgot to add an exhaust port. fixed that while keeping the mounts in tact.]

Current Design is big enough to hold two spools vertically with no spool holder. upon testing the spool holder is to large for the top. I'm updating the design to compensate for this properly as well as creating a spool holder.

Currently the design works for holding and drying filament.