Building on Anachronist's Nuts & Bolt Baby Dexterity toy, this version keeps the same screw dimensions but provides varying nut external dimensions. Your toddler can have fun stacking them in order of size (or in any order that pleases them).

There are six files to print:

• The main bolt, which has a head 225% of the original size
• The 200% nut
• The 175% nut
• The 150% nut
• The 125% nut
• The 100% nut

I printed a version with a silk filament, and pleasantly observed the nuts spin down with gravity most of the time after the initial thread. Tip: even if the nuts are spinning down themselves, this still counts as your toddler playing with it, and you may upset them by interrupting the process.

Note that the bolt is quite long compared to the head diameter, and a child might be able to get enough leverage to break it. Please use with adult supervision at all times.

This toy should be compliant with the small parts test in Health Canada's Safety Requirements for Children's Toys and Related Products, although the design has not been submitted for any certification.

I've included the .scad file I used to modify the original file (which is available on Anachronist's print page, https://www.prusaprinters.org/prints/129114-nutsbolt-baby-dexterity-toy).