I use the standard Radio Shack “helping hands” tool a lot when I’m working on electronics. It’s pretty useful for holding components in the right place while you’re soldering or working with small parts. They can be a bit of a pain, though, because the little alligator clips tend to move around, causing components or wires to wiggle out of place while you are working. There are a few positions that the arms work well in, and many configurations in which they are just not articulated enough to function well.
Instructables user rstraugh has a nice do-it-yourself solution to this problem: Third Hand++, a multi-armed, modular tool made out of adjustable coolant hoses.
I was familiar with the adjustable coolant hose systems used to spray coolant at cutting tools in the machining industry and thought that would be a great place to start. I ordered various nozzles and hose segments from my favorite online machine tool supply company and started experimenting. This is what I came up with. While it still has plenty of room for improvement it has served me well over the last 3-4 years.
These arms can be placed into pretty much any position and they will stay there.
Another nice feature is that you can make all sorts of attachments for holding whatever you need to work on. So far I’ve made a circuit board holder, a clamp, a mount for an LCD, and an extraction fan for keeping fumes out of your face.
The cost? About $20.
The modular attachment idea is the real killer feature here. In addition to circuitboard and probe holders, you can also make grounded or powered arms. Heck, why settle for 3 arms? I wouldn’t mind a big workbench octopus.
Third Hand++: A multi-use helping hand for electronics and other delicate work – Link