oh yeah I also have a an excalibur dehydrator should i ever need to dry filament.
Like airscapes said - most people who need to dry filament regularly - already have methods to do so.

things that you can't yet easily get for 3d printing.
idiot proof filament joiner. It's on my list of future projects. I'm looking at basing my joiner on a set of cheap hair straighteners.
But something where you just shover two ends into a slot, presssed the thing and had a clean joined filament would be great.

Also what we still don't have yet is a decent and reliable desktop widget to recycle failed prints, benchies ets back into useable filament.
A number of pople have tried - so far I've yet to see anything that either works or is cost effective.

Where people seem to fail is they just make an extruder. To keep the filament diameter consistent, I believe iy needs to be extrudede under tension, so a built in winder/tensioner is essential.

If I were you I'd look at the filament joiner as your project.
It's needed, it's not complicated and it's doable on a decent budget.