Actually had a similar thread to this come up in our Facebook group recently so I’ll just repost some of the bits from there
In terms of linkages, you might find this super old but super useful diagram useful
And as example bots, check these out. One is from Shakey’s site Nuts and Bots, where Shakey has screwed into the printed walls of the robot for the hinge, and used nuts and bolts between the linkage.
The other is built by Michael of Clements Combat Robotics. You can see here he’s used 1.5mm modelling brass for both the linkage and hinge.
