Quote Originally Posted by Nickhofen View Post
Hi Clive.
Nice input,thanks!
I will then go for 50x50x4, maybe?

Nick.
Hi, May I ask what rails/tracks/guides you are using and what is the method of attachment? What do you want to cut?
The span of the section is where you need to pay attention. Mass/stiffness can be your friend.
Welding can be you enemy with shrinkage and distortion. The 50 x50 x3 might be used for bracing , but the main rail support might be stiffer with 75 X 50 X 5.0 RHS.
Tool load and weight of the material you are cutting will also dictate frame material properties. Sorry not many answers and a lot of questions.

Paul