Robot: Vorpal the Hexapod

The servo size the project expects is MG90 size. Tower Pro MG90S work very well, as do Turnigy MG90S from Hobby King. Don't use SG90, the plastic gears can't take the stress of walking. (also the shaft spacing is different so you'd have to adjust the 3d models a bit). Clone/counterfeit Tower Pro MG90S are all over the cheap electronics places (and even amazon/ebay etc). If you see any price under about $6 for something claiming to be a tower pro mg90, then it's very likely to be counterfeit. If you see a price under $3 it is absolutely counterfeit, because even in large quantities real TP MG90S servos cost nearly $4 wholesale. We used to use clone MG90S in our projects, but we would test every one and reject the 10% that were bad. However, recently the factories in china have been churning out batches of clones with sometimes 50% bad servos so we stopped using them and switched to real tower pro servos. If you want to buy those clone/counterfeit servos for $2 or $3, buy a bunch of extras because you're likely to have a good percentage of bad ones. A lot of them have bad gearboxes that will fail within minutes of using. Many of them recently will lose their home position after heating up, the shaft will drift 30 to 90 degrees from proper position.