My steel framed router

**pavlo** · 03-03-2011

Hi FOX

Glad you like the router, I will PM you with as much information as I have regarding plans and suppliers.

One thing to bear in mind is that although aluminium is about a third of the density of steel, it's Young's modulus is also a third of steel's. This means that for the same geometry, you need to use three times as much aluminium to get the rigidity of steel. The benefit of aluminium is that the geometry of extuded sections have a high second moment of area (I) which gives good flexural rigidity.

**Jonathan** · 03-03-2011

Originally Posted by pavlo

One thing to bear in mind is that although aluminium is about a third of the density of steel, it's Young's modulus is also a third of steel's. This means that for the same geometry, you need to use three times as much aluminium to get the rigidity of steel. The benefit of aluminium is that the geometry of extuded sections have a high second moment of area (I) which gives good flexural rigidity.

That's what I was referring to, but you put it better.
Also steel is 1.7x more dense than aluminum, which is something to consider with regards to resonance.