I build up a very small Robotic toy for the Desktop.
Inspired by the cable driven approach, I just used cherry wood, some fishing cable, 7- servos (6dof + gripper) and an beaglebone black for control. It interpretes ISO GCode via webinterface...
Step 1: Base Construction of the Arm- Done With 5mm Boards From Planed Cherry Wood
since the robot is an educational toy, it constructed symmetrically which makes it possible to reach most positions in multiple arm configurations . So it becomes easy to explain the solutions of the inverse kinematic.
The construction is attached as ACIS .sat . and pdf.
Step 2: Milling the Parts
All the parts are small enough to fit onto the table of small desktop mills.
I myself used a LINUXCNC (Machinekit) controlled PROXXON MF70.
Feel free to choose your own machinery.......
Step 3: Some Bearings in Brass and Plastics
The bearings of the joints are done on a small lathe from brass an d Plastic.
Picture 2 shows the way Ibuild up joints 4 and 6. For Joint 1 I used a Ball bearing 25x12x10 mm.
Step 4: Assembly
I used very thin cables from fishing line in an uncompressed 0.5x0.9 Teflon hose. Its a little bit tricky to get the line into the hose, used a thin wire for this job!
The servo-motors are simply mounted on a Board, and the cables of the robot are connected to the original discs of the motors which got a small groove on the lathe and a small bore to make a knot .
Step 5: Testing
don't forget to test everything before closing the box...
Feel free to use a servo tester or the final controller...
Step 6: Closing the Box and Surface Coating.
Finally apply some clearcoat using a airbrush gun.