Grrrinbot! (Patreon)

Hinges and gears, together at last!  :P

This cheery robo-box features two rotational hinges connected by meshed gears so that as the lid moves upwards it also turns over, ending in just the right spot on Grrrinbot's head as it reaches the end of its arc of motion.  There are spots for magnets in case you want to pop some in for a more secure closure, too :)

Printing cogs upright is always a tricky proposition, but we're fortunate here that only a small number of the cog teeth are actually utilised in the motion, letting the rest be modified for printability without having to worry about keeping them functional as gears.

A more complex issue, though, is the hinging itself.  My usual approach to hinges with horizontal cones relies on a fairly rigid connection between two opposing hinge sides, and that's not necessarily the case here.  The limited connection between the sides means the whole thing would be prone to flexing open and dropping the lid, which would be no fun at all.  So, instead, the hinges are built from flared cylinders that extend from one part into a void inside the adjacent part, completely concealed, which not only serves to make the hinge functional but firmly fixes the two parts together, making the whole thing much more rigid.

Printing Tips

This is an articulated model, so you'll want to make sure your has a nice neat first layer and that there aren't any print artifacts like stringing or overextrusion that might bind moving parts together.

Grrrinbot prints assembled, with no need for supports, with the lid open and on the print bed like so:

Print Dimensions

Grrrinbot occupies 134mm x 115mm on the print bed and is 114mm tall.

Optional Magnets

As usual, this one's intended for 6x3mm cylindrical magnets, but Grrrinbot will work just fine without them :)

File Locations

You'll find this one on dropbox under 718 Grrrinbot

Link to dropbox post: https://www.patreon.com/posts/31697592

Further Thoughts

It would be really interesting to print this one with either a colour changing filament, or even just with a filament swap somewhere early on...

Happy printing! 

xoxo

Sven.