Servos are hard to get things for.

"Gamer_34567544;d-1003059" wrote:
I was excited to be able to build robots. However, I have yet to get everything I need to successfully build a servo. I wish there was an easier way to get everything.

There is, if you have testing cheats enabled, right click on the robot station and hit generate supplies (Think that's the name of it) it will generate all the materials you need in your active sim's inventory that includes all the parts you need.