Harmonograph

I have a (annually renewed) Merlin SeasonPass that is used to visit LegoLand Günzburg, Heide Park or LegoLand Billund. LegoLand Günzburg has the biggest assortment of bricks, so that's where I get the largest part of my supply. I visit the park at the start of the season to buy new parts or parts in new colours (for my mosaics), and I visit the park again near the end of the season hoping for a few bargains. If I visit the park the last weekend of the season (like I did in November 2015) than I am much too late to find something interesting... There was only one bargain left: the price of bricks in the Pick-and-Mix boxes ("Wühlkisten") had dropped from €70/kg to only €30/kg. An interesting price, but there were no interesting parts left in the boxes... You had to move at least 10kg of 64178-bricks before you could find some other bricks near the bottom of the boxes. First I thought to buy a few of them to resell them to Technic-builders from our LUG, but I ended up leaving the shop with approximately 1,5kg...
It was only when I got back home that I started thinking of what could be done with (just) this brick: a very sturdy construction! But what needs to be extremely sturdy??... Oh yes: something very, very heavy...

When I was a teenager I once saw an artist in a parc making weird drawings on a huge construction. I liked those drawings, but I had no idea what this machine actually was. The drawings reminded me a bit of the spirograph-drawings I made in my childhood, but searching YouTube didn't point me into the right direction. It was more by accident that I stumbled upon a video with a machine that looked a bit like the one I could remember from my teenage years. That's when I found out what these machines were called: "harmonographs". Now I could finally start studying the subject in detail...
I started with a two-pendulum harmonograph where both pendulums had a gimbal-pivot. Unfortunately I wasn't really satisfied with the resulting images. So I tried to make it bigger and turned it into a three-pendulum device: a drawing-table with a gimbal-pivot, and two pendulums to steer the pen (without gimbal-pivot). I preferred these drawings over the ones from the two-pendulum harmonograph. I have already made hundreds of drawings during two events from our local LUG, with many bedazzled looks from visitors...

I already regret that I only bought 1,5kg of this special brick: I want to enlarge my table and turn it into a four-pendulum device. I'm convinced that drawings from a device like that will even look better than the ones I have now. Time will tell if there will be a successor-harmonograph...