[Tim Skloss]

The Bosch extrusion is NOT a superior product. A local business that builds industrial robots out of extrusion has completely quit using the Bosch because it is notorious for vibrating loose. And on a FIRST robot that is too risky.

Furthermore, some of the numbers you quoted are funny. The pullout strenght of 300+ lbs for the 20x20 is simply impossible according to the tensile strengh claimed. The material will fail and release the fastener before you get to 300 lbs.

The specifications claimed for the item extrusion are from actual test data posted by the manufacter. You will NOT see actual test data for the Bosch. Since in europe--where item originates--manufacturers claims must be absoluetly guaranteed, you will see very conservative estimates of structural strength. In our experience the material can be up to 3 times stronger than claimed in the catalog.

Which is better for a FIRST robot? You have to weigh strength and reliability against your pocketbook... But remember the free market ensures that "you get what you paid for".