Because I am using one of the gearhead motors as the lifter I need to make the whole thing as light as possible while still being strong. So, I used 1/16" angle aluminum that is to be cut and bent into a rectangle and then attached to a servo. With another built just like it the two will act like butterfly wings when they open and close.

To bend the angle aluminum you have to cut notches in it to prevent it from overlapping when the metal gets bent.

There, now we can stretch a fabric over it to fill in the middle. But wait, there is a problem...

The aluminum was too thin and when I bent it it snapped. $3.50 down the drain. Hmmmm... on to plan B.

I made a new one out of 1/8" flat stock. This didn't break when it was bent to 90 degree angles (but it came close).

Now that we have the butterfly grabber solved we can move on to the lifter. Here you can see it in the retracted position. This allows it to stay within dimensional limits.

Here is the arm raising up. You will notice that there has been a notch cut into the chassis to allow the arm fit into the body when in the down position.

And here it is in the down position. Close to the ground but not too close.

Well, after some testing it turned out that the motors that were used for drive were not a good choice for the lifter. They have a small armature and a 19:1 gear reduction. So, I made another trip to the surplus store in search of a beefier motor and found another Pittman. Not only was it physically larger but it was geared down 63.5:1. This new motor is strong enough to lift a hammer but it started bending the chassis under the load. This new one will work perfect!

With the new motor mounted I can now mount the servos with the grabbers attached. Looks like it can pick up some thing that are pretty low to the ground.

This time there is no problem lifting and with the additional gearing it has slowed down to a managable speed.

And, here it in the retracted position with the butterfly grabber laying flat against the chassis.

Now I need something lightweight to fill the gap of the frame of the grabber. Something that can also stretch and conform to the shape of the object that is being picked up. Latex gloves should do the trick. I just cut the wrist part away from the fingers and it should work just fine.

There we go. A little stretching and they fit like a, well, a glove...

Here is one of the soccer balls that we use during hte robot camp. Let's see if Strider can hang onto it.

Yep, sure can!