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.
