Remember to do the thing! Now with Magnets!

Do you need to remember to do something periodically, but can't remember if you (or someone else) did? This easy print should help. If you don't have multi-color printing, you can easily use a sharpie on the raised surfaces to make a similar effect as shown in my picture.

I originally designed this to help remember and signal to myself and my wife when the dog was last fed, so we don't overfeed the little guy (yes, I know he's cute). However, it dawned on me that this could be great for remembering to take medication or other periodic tasks.

Printing instructions:

• Filament: I printed this in two color white/red PETG, but any filament ought to work.
• Sizing: Putting the 3 parts together should work out of the box, as I designed in tolerances, but if it doesn't, it's trivial to either sand, use a little grease, or slightly scale the spinner and the arrow by 1%, which are the tiny “cheap” parts to print.
• Orientation: The small number of overhangs here are not aggressive, but I recommend printing the arrow part wide-side down. Go slow for this little part to avoid knocking it over and to get a good fit, or use a brim.

Assembly:

1. The spinner should snap in place by pressing it down on the shaped post.
2. The dovetail arrow should slide in place, as shown. If it's too loose for your liking, scaling it slightly up can make it stick more.
3. Label slots: You can use a label printer to put labels of your choice in the designated slots, or you can use a mailing label and just write on it. You can write directly on the slots too, of course, but sharpie tends to bleed a little on 3D printed parts making it harder to read.
4. Magnets (four 10x2 mm) go in the back with a touch of superglue or whatever adhesive.

If you don't have 10x2 magnets and want another size, I've included the STEP file here to make it easy to modify the holes for whatever size magnets you do have. If you want a version without magnets for some other surface, the plain jane versions are available here: https://www.printables.com/model/417368-periodic-task-marker-for-pet-feeding-medication-or .