Drive Sizing 101

[Chuck Glick]

Originally Posted by IKE

For those looking for the extra credit, what Efficiency did 217 use in their calculations?

I am going to say somewhere in the 60%-70% range, but it could also be as low as 50%. The reason I would guess 50% is it is half of the full power, so if it could do it in the set constraints at 50%, then at 100% or anything greater than 50%, it would be guaranteed every time.

[Paul Copioli]

Tom,

The force on the latch is much lower than you think. The design we are using is made such that the contact forces on the vertical pole are greatly reduced.

Paul

[Tom Line]

I'm very anxious to see your comp bot then. With our initial design, when the bot was out at the end of the 36 inch arm plus the 18 inch riser, we had 54 inches (call it 4.5 feet). With the 150 pound robot at the end, that's 675 foot-lbs. However, our initial end effector was only 6 inches tall, so the torsion on the top point was 675 ft-lbs / .5 ft = 1350 lbs. Of course, we were trying to package within a 16 inch tall robot, which is why we limited it to 6 inches tall.

Since you're not worried about the tunnel, I suspect you didn't have that constraint regarding packaging.