Manipulating the Future

This project is a home-brew of a parallel manipulator robot known as a Delta-Robot. This robot has 3 degrees of freedom and allows for very fast positioning of it moving platform. The project started as an idea for learning\teaching kinematics. With too much on the go with other activities progress was idle for some time. Although the mechanical work is near done there is a load of software work now to make the robot useful.

The interesting feature of this robot is its design symmetry. There are relativley few different parts. The XYZ movement of the triangular platform (end effector) is accomplished via three angular joint mechanisms that are placed 120 degrees apart on the base.

Note the implementation shown is still missing the mount to hold it upside down from what is pictured.

The joint mechanisms are each controlled by a separate model airplane servo that pivots the fore arm. This arm is attached to a parallelogram seen as the parallel white rods in the photos. The parallelograms pivot on the fore-arm and the end effector. Again, three assemblies of the servo, fore-arm and parallelogram are placed at 120 degree angular spacing.

From the two photos shown next one can see the rather large range of motion the end effector can have with little change in the fore-arm's angular position.

The project is built with black lexan, while delrin and white fiber glass rods. Although it is not as light as it could be the implemention is sturdy and allows for a good deal of force.

The servos are controlled by a serial servo controller. (The small circuit board shown).

The end-effector platform can be seen below as the three-legged black lexan piece. The joints for the parallelograms are also made from black lexan. Some 8-32 nylon screws hold the pieces together.

More on all this later......