Like many of my projects this began with the chance finding of a lovely old brass bowl in a thrift shop. I paid a dollar for it and walked out thinking "I love the patina - it would make a great lamp..." and when I got home tossed it into the box of brass bits and pieces collected over the years from my frequent visits to the recycling plants, the junkyard and the thrift shops I frequent. I forgot about the bowl for nearly a year and then had a hankering to make a floating arm desk lamp in the Steampunk genre and re-discovered the bowl. This provided the impetus and I went looking through my boxes for other bits and pieces which could be re-purposed to provide key elements of the construction. Many of my projects start this way and in a sense, this is what makes them difficult to present as a how-to-do-it instructable. So much of this depends on what bits and pieces you may have to hand or can find, that even planning is no more than a vaguely realized "Concept Drawing". The actual details will vary depending on what components one can find, or, in hitting a problem, how one chooses to solve the problem.
I am a self-confessed amateur, learning as I go and am indebted to the online maker community for all the open-handed and generous sharing of tips and techniques from which I have learned so much.
The tools used here include a drill press, angle grinder, hand file, taps and dies and a large and a small soldering torch. I like the Steampunk genre because it allows me to use the materials I most like working with: well-seasoned hardwoods, brass, copper and steel, as well as using simple mechanisms such as springs, electro-mechanical or clockwork, rather than "black box" electonics. (Not to decry electronica - just not in Steampunk!) Aesthetically, It also allows a certain "industrial functionality" of finish, which makes the crudity of finish and the overall roughness of my pieces almost acceptable.
In all my projects I have two criteria: the piece must work as planned and it must meet my own aesthetic standards, what I call pretty functionality. Half the fun is in solving the problems as they arise and as there's never only one solution, the project could go off in any number of ways at any stage, which is what makes it interesting. I'd love to hear about anyone else's version of this sort of construction.
Note: To make the mechanism clearer, check out the video on http://www.youtube.com/watch?v=AvsyH4dtlTE shown above..
Step 1: Lamp Base
The brass legs are made from blank brass rod - a scrapyard find, thickened at each end by soldering a matching piece and then grinding to a teardrop shape with an angle grinder. The construct was then drilled to take the threaded end of an industrial electrical contact ( For some reason, I quite often find these at the local metal recycler and always snap them up when I find them as they seem to be infinitely adaptable). The threaded pin was then shaped by filing in a drill press ( in this case acting as a turning device, like a poor man's mini lathe).
Step 2: Rotary Mechanism and Lock
The lamp base is curved and the arm is a long lever, therefore it will fall away from a selected position. Accordingly a locking mechanism using a toothed wheel and a toothed pawl were devised. These are shown in the images attached. The arc of rotation of the lamp was limited by arresting pillars as shown and symmetry was maintained by using identical gas-line connectors to provide the base for the locking mechanism and the electrical wiring egress point from the base to the arm of the lamp.
Step 3: The "Skeleton" of the Arm
The skeleton was put together using components found in my boxes of scrapyard finds.
Step 4: The Rigging or Muscles.
The outriggers were added to help disperse the springs, for aesthetics and because they were fun to do.
About the only principles I can enunciate after all this messing about are these:
1.In order for a joint to "float" in a selected position, the forces trying to extend the joint, must match the forces trying to flex the joint.
2. Start by trying to animate or float one joint. The more joints you add, the more complex will the rigging become and true balance harder to achieve.
3. The arm should be heaviest and bulkiest at the base or shoulder and get lighter towards the hand. failure to do this will make the entire construct top-heavy and liable to topple over.