In the bottom of the photo is a hand gripper. You squeeze the unseen handle which pulls a string which pulls the bottom of the gripper part, making the yellow lever pull against the nonmoving arm.. I made a servo version that has three joints so it can grip, move left/right and up/down.
Look at all the sheet metal I had to cut form and bend! So where did the metal come from? What did I need to fabricate it?
Step 1: Raw Material and Tools
Tools needed is a marker, hammer, and sheet metal cutter or tin snips.
Cut the molding bigger than you need. Bend with plyers any rounded edges (like on the stud), then lay on cement and hammer flat. Make your marks of where you want to make your cut then cut. use a small square so your lines are true.
Step 2: Brackets and Holders for Servos and Motors
Your cuts and especilly your bends have to be square or your finished piece will be out of square. On most parts this isn't critical, but you will find out that on some pieces it has to line up with the previous piece or the next one. If you make a mistake, just unbend and hammer it flat again.
Here a bracket is being formed. Make your line, bend it by starting with the line on the edge of your table, hold with your fingers on top and your thumbs on the bottom and push.
Look at some finished pieces. It isn't that hard to make the cuts, it's knowing where to cut and where to bend.
Step 3: Views of Finished Remote Controlled Gripper
Hinges and such will need long--two or three inches long-- skinny bolts. I call a bolt anything that needs a nut screwed to it. Your joints will need some. Look at the finished gripper. You will see the joints have a bolt holding it together and one side of the joint is firmly attached to another part.
Step 4: More....
After cutting the first two cuts for a servo bracket you will scratch your head wondering how to get that inside cut done. I would bend the metal one way so I could get my snips in place, cut it, then bend the metal back and hammer if needed. This is a trial and error experience. Be easy on yourself. Mistakes will happen. In the end you will get the job done. It might look like crap but it works, right? Your next creation you make will be better than the first one because you now have some experience cutting, shaping, bending, drilling metal. Rebuild your device or start another. Each time it will function better and look better. It won't be long untill you have a working robot that can move like a machine is supposed to.