Quote Originally Posted by NordicCnc View Post
Have you built any machines with face-mounted rails and 160x80 extrusion gantry that was not stiff enough to mill aluminum efficiently?
Very few on this Forum can answer that question regards 160x80 profile because they won't have needed to change if done one before the other.!

I've built 5 machines that use face mounted and 14+ machines that use top/bot and all cut aluminum perfectly fine. These machine sizes range from 4 x 2 to 10 x 5 and the 6 machines with face-mounted are all 8 x 4 or 10 x 5 machines because saving space wasn't an issue. So in this case, I went for the easiest method of fixing and setup, also fewer parts to machine.

Honestly, it's not something you need to worry about on router that's mostly going to cut wood with occasional aluminum work.

One other method I use often, esp when needing to keep gantry low but with the highest clearance is to mix n match bottom rail on the front, top rail on the top. This gives the most clearance under the gantry and keeps gantry height low.

So like I say use the method that suits your needs because no one is better or worse than the other. You won't see any difference when using the machine.