Why not use unsupported rails?

[Shinobiwan]

If you could show how strong supported rails are attached to 40 x 40 profile like a lot of machines are you will see just how weak they are in comparison to your model?

And your point is? They'll still be stronger than the same size of unsupported rail which was the point Jonathan was making.

PS I'm a performance engineer by trade and do a lot of modeling. i would get shot down in flames if i presented statements like that without all the facts.

Obviously not a great one since your using unsupported rails

Use some common sense in this thread, realise this isn't a white paper on rail strength and that everyone here is a hobbyist