Few weeks ago we spotted on Hackaday the post about Open Theremin, on first look nothing challenging, just classic two HF oscillators with mixer which detects your body/hands proximity to the antennas and change the frequency.
Connected to Arduino and generating variable pitch and frequency tones.
The real gem was in one of the comments. The video how this guy is manufacturing the kits with do it yourself pick and place machine which he built from $50 ink jet printer mechanics.
Knowing how demanding to operate are the real professionl pick and place machines I know what amount of work is to build such thing from nothing, to program and debug it and to actually make it work something useful. This is months of efforts! The DIY P&P which actually works deserves our admirations!
olimex 
Feb 19, 2016 @ 22:19:07
Any technical details on how to reproduce this at home? Has he published documentation about his pick-and-place?
Feb 22, 2016 @ 22:28:03
From what I understand.
He seems to use a 3D printer firmware (reprap and code (gcode), pollulu step driver command http://www.reprap.org/wiki/Pololu_Electronics )
Instead of using an extruder, he use a (cdrom) servo on the needle with a vacuum pump.
i don’t really know how he decides to manage the vacuum pump (wich gcode so the arduino activate the right relay/…)
What’s innovative in it’s hardware, it’s his use of recycled materials, and the idea to use gcode to manage the pick and place. A script helping creating it would be fun interesting.
A great augmentation (and complicate too), would be a camera for in place calibration, alievating the need to produce the exact same batch at the exact same place each time.
Mar 19, 2016 @ 15:07:17
A very inspiring video – well done. I think I want to make one as well now and your video has given me the confidence to have a go.