Single spool dry-box

Update August 8th, 2023.
I realised I didn't need to drill the box for the humidity sensor, I simply printed a revised adapter so it screws into the hole designed to pour out the cereal etc. that the box is designed for.
The new humidity sensor adapter is two pieces - HumiditySensorTop and HumiditySensorBottom.

I decided I needed individual dry boxes to print directly from. I have been using a dry box with multiple spools but this was less than ideal since I needed to constantly open the box to change filaments which degraded the silica gel quickly - and was a pain!
Amazon (UK) sell a variety of 4L "cereal boxes". The ones that worked best had no ident for a hand hold, instead having just external ribs. These ones are ideal: https://www.amazon.co.uk/dp/B089YPCYZG?psc=1&ref=ppx_yo2ov_dt_b_product_details.
I designed spool holders for lengths of standard 25mm wooden broom handle.
I used the angled filament guides from this: https://www.thingiverse.com/thing:2896547 with the 4mm t