BOTTOM LINE, UP FRONT (BLUF)

The most important feature here that I haven't seen in similar models is that I put a tab on the top of of my pendula.  These has two effects:

• You can start the motion from above
• You get a second visualization of the wave at it evolves by just looking at the tabs on top

Hold Tight

There is enough momentum when you start the model that it will tip over if you don't hold onto the frame.  Once it starts, the forces are no longer synchronized, and you can let go.

[UPDATE] After playing with this for a few days, I've realized that you don't want to push the pendula all the way out – if you push them about 45 degrees, you get a really nice wave effect, both on top and looking through the side.  So, if you're pushing the pendula so far that the model tips over, you've pushed them too far.  Yes, I know, it's counter-intuitive.

All the Gory Details

Credit where Credit is Due

This was inspired by @3DPrintBunny's beautiful model and other, similar, models.

Design Goals

• Remove as much friction as possible (I found that some of the pendula stopped very quickly when I printed someone else's model)
• Remove the need for spacers / reduce the overall number of parts (I failed at this and put the spacers back back – without them, the pendula knock into each other)
• Start the model from above (I found I had to drop the pusher, which felt awkward)
• Don't need friction fits or glue to keep the frame together

Construction Notes

Pendulum Tolerance

You want the pendula to slide on with a little bit of friction at the ends, but not so much that you have to force them on (and break them – yes, I did this).  It should feel like the friction between the nozzle and the business card from the old days (5 years ago :-) ), when we had to manually level our print beds.

Given the variability from printer to printer, there's no way I can make 1 model with dimensions that will work for everyone.

I recommend printing one pendulum first and then adjusting the fit as necessary by scaling it in your slicer.  I would start with steps of 1%, and then fine-tune even more if you feel it necessary.

Then use that scaling for all pendula.

This model doesn't actually work “out of the box” for me – I had to scale the pendula to 99%.

Spacers Work Better on the Bottom

The purpose of the spacers is to keep the pendula from hitting each other.  That works a little bit better if you put them under the bar rather than over the bar.

Hey!  Where's the Pusher?

I didn't bother – I just use a wooden pencil to start the motion.