Let's Make Robots!

Small nuts and bolts, where do you get them?

I asked this question once before in a bad spot I think. Where do you all get small nuts and bolts. I went to a local hardware store for really small nuts and bolts, like 2x20mm, 2x12 mm, and similar sized imperial nuts and bolts. I walked out of the place with like 30 bolts and 30 nuts and it was over $30.00!!! I used all of them on one project and still have to go get more. But at 45 cents plus a bolt, it is gonna bankrupt me. Is there a good place online to buy these things in like 100 packs or boxes or something for cheaper than a dollar for one nut and one bolt?

Servo selection problem

I have been working on a robotic arm for my first solo project from scratch. Everything has gone well for the most part, I will post the robotic arm when it is finished. I have run into a problem though and need some help with what to look for in a servo as far as specs. The problem is, the first vertical joint cannot handle the weight of the rest of the arm very well when it is idle. In motion, the arm swings fine, when at rest, it has a tendency to just fall over. I am assuming I need to buy different servos for use in my arm.


Has anybody checked out this challenge.gov site?