Drawbot: much better TSP solving

Optimization is the name of the game when attempting to solve the Travelling Salesman Problem (TSP). I’ve figured out most of what Lin/Kernighan is saying and then implemented it to run as fast as I can get it to go. Here’s the progress since the last picture I posted.
Here’s one of the Seattle skyline for the Seattle Maker Fair

It helps if you back up and squint. No really, it’s like pointilism paintings. Ever heard of the Group of Seven? Like that.

Here’s the results of the Drawbot working on the above image done by the TSP solver last night.

It ran for three hours and then failed when the laptop went into sleep mode while I was at the VHS. The mess in the top left is because I tried to draw the picture twice – once it failed when the stepper motor got warm and caused the bobbin to slip off the shaft. In a future version of the drawbot I’d like to try bicycle chain and sprockets instead of bobbins and thread.

Got any suggestions for pictures I should draw? Post ’em below!