Clacky Cog Contraption (Patreon)

It's a noise maker!  And it's an excuse to put cogs and gearing to work in the service of making really annoying sounds.

So, wonderful people, let's look at what this is and how it works!  The core of this model is a series of interlocked cogs, and those are actually from another model that I've been working on.  Sometimes projects get unexpectedly derailed and turned into annoying noisemakers instead, it seems.  So, we have these cogs, and the one at the end is double the size of the rest, giving us a useful gear ratio for extra noise creation.

The handle, of course, is attached to that big cog, and turning the handle turns all the small cog and finally drives the large-finned wheel at the other end.  Those fins pluck at sprung plates that snap back with a clacking sound.  The teeth on the cogs are spaced so that the four sprung plates are struck in pairs.  

Why, is this, you may ask. Well, print-in-place models need a reasonable gap between parts in order to print without fusing together.  But, this gap is potential movement, and when the finned wheel pushes the sprung plate it pushes back.  Since there are diametrically-opposed pairs of plates, though, those pushing forces balance out and the finned wheel stays where it's supposed to. 

A handle extender, the Wrench Handle, is provided for more convenient use, but it's by no means essential.

Print Description

This is an articulated model with lots of moving parts, so make sure your bottom layer is nice and neat and that there aren't any print issues like stringing or overextrusion that might cause moving parts to bind together!

Filament Thoughts

When test printing this thing I found that the filament involved made a huge difference to the amount of force needed to rotate the handle and get things snapping.  ABS actually worked best for me, probably because it's quite flexible.  I can spin my ABS prints around by the handle, but there's too much force needed for the PLA prints to really do that usefully.

Print Dimensions

The Clacky Cog Contraption occupies 126mm x 64mm on the printer bed and is 52mm tall.

Supports Needed?

Not at all!  Designed for straightforward printing!

Scalability

This one could probably scale up a little without too much issue - the cogs will get a little looser, which won't be a huge issue right away, and the springy noise making parts will thicken up a bit.

Print Orientation

The noise maker itself prints with the handle facing up, and the wrench handle just prints flat, like so:

File Location

You'll find this one at at 637 Clacky Cog Contraption

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

Further Thoughts

There's actually an alternative handle to the Wrench Handle - it's very similar but adds a kurled swivel handle for easier turning.  However, I have to admit I like the simpler Wrench Handle much better, so that's the one in the photos; the file is there on Dropbox if you want to give it a try, though!

Happy noise making!

xoxo

Sven.