Cheap brackets and hardware?

Does anyone know a good place to get brackets and other metal hardware for mounting servos, building robot arms, etc. ?

Try McMaster-Carr or Pololu - Hardware

http://www.robotshop.com/ca/mechanics.html

We use Meccano (US = Erector set) but it's expensive. Pic below shows simple robot arm in its early stages. The strip is used a) to mount the bottom servo in the small box so it doesn't tip and b) for the arm itself. That's my daughter's work on her arm so far.

I'm looking for something cheap too.... some kind of strip with no holes maybe, so they can be drilled as needed.

I'm looking for something cheap too.... some kind of strip with no holes maybe, so they can be drilled as needed.

I often use copper clad PCB boards.
I bought 12X12 Single Sided & Double Sided 1 oz PCB material and use this.
I cut them to length/width sand the edges and drill holes where I need them.
You have the option of soldering nuts/screws to the copper foil.
You can also solder (on both sides) a piece of DS pcb to a PCB arm, at right angles, then mount things.
The fiberglass is strong and won't kink.

Big chain hardware stores usually have angle, C channel, tube, flat, and box steel and aluminum. You can bend it into shape pretty easy with a hammer and piece of wood/metal. C channel is good if you need something thin and rigid.

Check out 8020 (www.8020.net) for more heavy duty stuff.