Quote Originally Posted by leadinglights View Post
.... The same mass of aluminium should be more rigid than steel...
about 3 times more rigid... but also 1.7x linear length, i.e a beam 5cm x 5cm steel will need to be 8.5cm x 8.5cm in aluminium for the same mass, or 6.5cm x 6.5cm for the same rigidity, but because it is less dense it will more easily transmit vibrations from motor to workpiece partly destroying the benefits...