Still going to figure this out as well. Might have to make these mounts a bit higher or add in some conduit legs after all. However, I will be using it mainly for milling, so don’t need that much height. Also, less height equals more rigidity / accuracy is what I read in most discussions here.
Most builds have a table, with the Foot+conduit+Lock_Corner legs and have their spoil board bolted on top of the table. I will have the 4040 extrusion + the above Frame_Corner part and my spoil board will be mounted below the frame. Using the conduit size calculator, I’ve determined this is the same as having 72mm conduit legs, which translates to a 85mm work height. Seems a fair amount?
Here is my calculation for this:
Normal build - standard legs - 72mm conduit - Lock_Corner (adds 7mm on top of conduit, before connecting to Bottom_Corner) - 20mm spoil boardDistance top of the spoil board to bottom of Bottom_Corner = 72 + 7 - 20 = 59mm
4040 build
- Aluminium extrusion (40mm high)
- Frame_Corner (19mm high)
- Spoil board mounted below the frame, thickness irrelevant
Distance top of the spoil board to bottom of Bottom_Corner = 40 + 19 = 59mm
Conclusion
4040 build == normal build with 72mm legs (which means 85mm work height)