Sunday, 14 July 2013

The one-armed bandit

During 1983 and 1984 my father and I collected the Home Computer Course partwork magazine published by Orbis in the United Kingdom.  At that time, I was 12 years old, and spent my time writing programs on a Sinclair ZX81 and BBC Micro (model-A).  I also tinkered with wires, light bulbs, and speakers, building the most basic of circuits, but my knowledge of electronics was rather limited back in the day.

I was fascinated with robotics, and this is the article which started it...

The Home Computer Course magazine

The article featured the Armdroid 1 robotic arm produced by Colne Robitics Ltd. This was available in kit form, or ready built, and designed to meet the needs of light industrial and educational users.   I wanted one !

Wind forward a few years, I'm studying at University and too my surprise, the computing department was having this clearing out sale (mostly junk).  On the top of the pile was this broken and sorry-full looking Armdroid, and I grabbed it for a mere £20.

The arm was really in a mess, the strings only just holding together, the pulleys on the Steppers broken - the arm simply couldn't support it's own weight!  Next problem... How the hell do I connect it up to a computer?   This was still in the days of pre-Internet... I had the University look in every cupboard and everywhere including the library for any documentation, nothing was found, the arm was soon to be abandoned once again.  Of course, a quick google search today, blue prints, user manuals, and documentation can easily be found.

I recently had the idea of restoring my Armdroid, after all, I've been threatening to do this for a long time.

There are mechanical problems to be sorted, possibly problems with the on-board electronics which is really an unknown quantity, and finally interfacing to a Raspberry Pi.  I have in mind building a web-based application and control the whole lot from an Android based mobile phone, or tablet.

My Armdroid in it's current condition:

Armdroid before restoration

The broken pulleys:

Armdroid - Broken pulleys

I also have the hand controller, and used this to spin up the motors on a bench test many years ago.  All the stepper motors ran well, lets hope they still do...

Armdroid Hand Controller

This blog, which incidentally is my first, will follow this adventure, I'll update as often as possible, but I cannot promise it will be every day.  I hope you'll enjoy reading... and if you have one of these arms yourself, can help, answer my questions, or maybe I can answer your questions, then by all means drop me a message...