Building a Brachiograph

 At Liverpool earlier this year, Andy Piper was demonstrating his brachiograph, or lolly-stick drawing robot arm.

Ever since I first had my ZX81 I've been mildly curious about robotics but have never taken the plunge. More recently I've been looking at various plotter projects, even bookmarked a few. Seeing this one in real life and seeing how cheap and easy it was to build (and my boyfriend chucking some servos in my direction) finally tipped me over the edge. 

This project turned out to be, as billed, the perfect gateway into robotics. It really is very simple to build and there are tutorials online, including from Andy himself. Thanks for all this Andy!

Lots of hotglueing ensued. So far this has all been very robust. 

To make the wiring neater, I made this little distribution board.

First I screwed the Pi Zero down and found that I couldn't plug anything into it, so had to cut a little plinth for it.

I'm not going to pretend that installing the software went without a hitch. It went as well as you expect with open-source software - you follow instructions to the letter and at some point see a screenful of gobbledygook. Perseverance is the key and I don't think any of the problems I had were anyone's fault except my own. 

Once I got to the part where you run the software and the motors start to twitch, I thoroughly enjoyed myself.  I'm not the world's biggest fan of Python (understatement) but that's what we have and when you're at this point, it's very easy to make the pen go up and down and move the servos to any angle with a command. This is where you set it up and calibrate the software, which was very easy. 

I very quickly got to the point where it was drawing one of the sample images. Even though I'd built this by just following instructions, this was (and still is) incredibly exciting and satisfying. 



I didn't have luck installing the vectorising software on the Pi itself, which would be convenient (it kills the Pi Zero(1) to try and install it. I guess it would take ages to run it too) but it's easy to do that elsewhere and just transfer the .json file onto the Pi. Here are some images I've made: (I took the photo especially)


I tried felt-tip pens, but the drawing pen (above) looks best, I think.










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