Use-Up-Reel-Ends Box

Out with the old reel, and in with a new one! Some problems that come with printing parts using the last bit of plastic in a reel have been bugging me for a while, as it's usually difficult to judge whether something that you want to print will use up all the remaining plastic, and how it does so.

You can take an approach of printing something so large that there isn't quite enough plastic to complete it, and the object gets truncated, but there are very few basic printer parts with a large unnecessary section at the top for your uncertainty to fall within, so most of the time one can't be sure if the printer will run out of plastic before finishing a crucial section.
You could also run a few print jobs of very small parts, but then you either have a significant length of waste plastic at the end, a final print of small parts that may not be useable if you run out halfway through, or you end up printing one of Zeno's paradoxes to try and avoid either of those fates.

I've tried to develop something that solves the first option, while always producing something useful at the end, so long as you're within a very wide printing margin. I'd say this print comes with an element of a nice surprise in terms of what size your box is, but you might want to check on the print as it runs out of filament, and stop it on a layer just before the loose end goes past the filament drive, so that you don't end up with a mess or have the extruder drive grinding away at its idler for a while.

Alternatively, if you have some awesome ninja printing skills, you might be able to get a new reel of plastic on whatever spool you use, in time to feed the new starting loose end in directly behind the old end without stopping the print. However, if you could manage that without hiccups in nozzle output, then you wouldn't even need this thing to begin with.

These handy trays can be used to sort small fasteners, jewellery, fishing tackle (all the same really) or similar bits, with a lid that gets completed at the start of the print.