From my understanding. Steel has great tensile strenth than aliminium. If you are going to the effort of making a solid base then you might as well use steel all round.
Besides steel is far cheaper too. Consider that most professional machine are made of steel and not Ali. If you go for concrete fill, you can always add glass fibres to it to give it far greater strength and stability.
Personally, if you are just cutting timber, then all these measuers might be a bit of overkill. |