Ready for a challenge? Try one of the robotic arms from Lynxmotion. I got their AL5B arm kit, which sports a 5oz lift capacity, five joints, and a reach of 7½ inches. I assembled it in one evening, and I’ve been having a blast with it ever since.
All arms in the product line are based on the company’s Servo Erector Set parts. These are prefab aluminum pieces designed to mate with standard R/C servomotors. You can buy SES parts separately, too, for your own arm designs, or to modify one of the stock arm models.
The AL5B is for experienced builders. The hardware comes in numerous bags, and it can be a trick keeping track of everything. I suggest you open each bag only when you need it, and keep a measuring tape nearby to check the length of screws. Study the online assembly instructions ahead of time while you wait for your kit to arrive. The kit doesn’t require soldering, but needs a base you supply. I used a piece of ½”-thick plastic.
Included in the AL5B kit is Lynxmotion’s SSC-32 servo controller board. Connect it to your PC (via serial cable or USB-to-serial adapter), and run the free FlowArm software to control the motion of each joint. Record complex motions and play them back with the click of a button.