Download the free pdf with instructions here.

It took quite a number of attempts to get this to more or less work. It still occasionally ‘hesitates’ or gets stuck, but I believe the only remaining improvement would be to add a bit of oil or lubricant to all the hinges, which I am not prepared to do.

After a lot of trial and error, it appeared that the only design that could work has a difference of half a unit between the length of the red ribbon elements and the yellow blocks. If the difference is zero, then the ribbons are too tight. If the ribbons are one unit longer than the blocks then they are too loose.

So, half a unit difference. This meant that the blocks had to be build ‘sideways’ ( orthogonal to the ribbons ), so that they could include thin lift arms. And because there are no suitable pins and axle-pins that connect half unit-wise, the blocks are not of the most elegant design. I know, the 1,5 pin exists but it has no ridges and makes for only very loose connections. The 1,3 pin exists, but it is not strong enough.

Lastly, the blocks had to have rounded edges so that the ribbons can easily glide around, but since the blocks are built sideways, this then led to messy add-ons.