Small Mill very early design stage

[irving2008]

.... 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...

[leadinglights]

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...

Hopefully easier to address than many of the other potential problems. Modern motors, whether stepper, servo or BLDC tend to be smooth and powerful and compliance for damping in the mountings of less consequence than in ballscrews, guides etc.

Mike