Everyone in the 3D printing community know about the issue. Filament spools run out. You want to start a large print, but are unsure if the filament will be enough. A filament sensor may tell you when to change it, but you don´t want to wake up in the middle of the night to change filament. Also if the printer cools down you will find a loose print on your build plate.
In addition to that: What if after 10 hours of printing you make a mistake while changing the filament and the whole print gets ruined?
So usually we take a new spool and keep the other for smaller prints. This usually works out, but then there is the rest of filament, which is not enough for those small prints.
One idea is to slice them together and print some fancy vase you don´t need. Well, the slices may break and again you wasted the filament.
I usually tend to keep any filament longer than 20cm in storage. Just in case I need it! Today was the day.
While developing a new project I needed to print multiple prototypes to see, if that works out and what not. Starting from a simple design I worked my way up to get more and more fancy. Check the objects in the pictures. From left to right you can see the basic idea growing.
I was there sitting next to my computer, so I simply used all filament leftovers I found and stuffed them into my printer, while designing and updating the CAD files.
As you can see on the images I used some red filament left from printing Nintendo Game Case holders, when that ran out I emptied some black filament and so on and on. I could have sorted the colors, but where is the fun in that. Thats why the last part (top right in the images) utilized six filament colors.
Now all the small pieces of filament in my collection are gone and I also emptied three rolls of filament, which my shelf is thankful of.
Since I printed the prototypes using a direct extruder the left overs on each spool are about 2-4cm of filament. Also all those longer pieces are gone now. Used in a nice way. Most of the printed parts will be dumped anyway, as they are useless. I broke some or cut them to fix CAD issues. They are trash anyway, but the filament I used for this already was trash. Why print them with a full spool, when you just invest a little work and save money.
Yes, it is a little more work and you need to check your printer every now and then to manually change the filament, but you will get better and better on doing that. And in the future when you really want a multi color print and need to swap the filament you have tons of experience.
Happy Printing!