Inspired by an excellent example in another forum (
https://modelshipworld.com/index.php?/t ... ent-452268 and newer version further down in the thread as well as a review of it:
https://modelshipworld.com/index.php?/t ... ent-473797), I decided to put into action something that I had planned to do for a long time. From my late father’s estate I inherited a cast-iron foot that presumably belonged to a some sort of chemical laboratory equipment. Not being impressed with the commercial ‘third-hand’ I kept this piece of cast-iron with the view of converting it into a tool with less and better controllable degrees of freedom. Also just having a pair of cheaply made alligator clamps didn’t add to the useability of that tool that, in consequence, spent most of its life on the shelf. I also inhereted a good quantity of pre-war quality alligator clamps.
Third hand with small hooks for rigging workThe cast-iron foot was de-rusted and a proper seat for the bar-clamp had to be filed – I could not find a way to clamp the piece to the table of my milling machine. The foot then was primed and painted in my favourite ‘bottle green’ (RAL 6007).
Third hand with small clamps in steelWorking predominantly in small scales with tiny parts, I sized the tool appropriately. The main bar is 6 mm steel and the two pillars are 10 mm aluminium. I actually prefer steel, but in this case working with aluminium was faster on my small machines. The arbors for all the clamps are 4 mm steel rod. The diameter of 4 mm was chosen, as the alligator-clamps have sleeves that are meant to be pushed over 4 mm-banana-plugs.
Third hand with alligator clampsThinking about the likely kind of applications, I made a pair of small sprung clamps from steel, a pair of larger toolmaker-style clamps (excellent idea by Michael, btw) in aluminium to be used for soldering, a pair of small hooks in 0.5 mm piano-wire for rigging tasks, and a pair of collect-chucks.
Third hand with toolmakers-style clamps in aluminiumThe collet-chucks are a commercial products from China with ten collets that clamp from 0 to 3.2 mm. I thought this might be a good idea for clamping wires and perhaps ropes safely without distortion or marring. They were so cheap at 1.50€ for a chuck with ten collets that there was no point in makimng them myself.
Third hand with collet chucks to hold wires etc.I also plan to make set of clamps from bakelite for soldering, but have not received the material yet.
The thumb-screws are also bought-in, as I have local source here in Paris that sells them for one Euro a piece, which is not exactly cheap, but good value considering how much time I would have spent making them myself.