Custom bench from 40mm "Maker Rails"

[sixtimesseven]

Having a few server rack sized instruments which are generally to deep to put onto a standard electronic workbench I decided to build my own.

The underlying structure is built using standard 40x40mm I-Type aluminium extrusions cut to size. The workbench is a 27mm and the instrument shelf is a 19mm beechwood plate. Size of the work table is 2000x1000mm and the top shelf is 2000x600mm.

So far I tested a couple of configurations and decided on the size of the instrument shelf and workbench. I'm currently oiling the plates and deciding on some last points:

I'm still undecided about the exact construction of the shelf and the support structure. I find that the setup now is very stable. The height of the top shelf is pretty good so that instruments up there can be viewed and manipulated seated and standing. Also the height is perfect to place a monitor below on the workbench.
But I'm not sure yet about the front beam of the instrument shelf. It provides optimum stability and might serve as a shade for LED lighting behind and as an attachment point for cables and probes. On the other hand while not in the line of sight to the monitor - It still seems a bit to close up.
I might move that beam back behind the line of the monitor (while leaving the side structures as they are).

Another thing are the additional shelves. The idea is to fit them between the top shelf and the workbench to put smaller / more regularly used instruments there (oscilloscope, bench multi meters usw). The monitor(s) should also be suspended so that the entire workbench remains essentially free below the shelves.

One last point is the attachment of the wood plates. I'm not sure how much they will expand / contract over time so I do not want to screw them down too much. My current idea is to just screw together the bottom / top structure where they meet with two M8 bolts trough both beams and the 27mm plate. And similarly screw together the top shelf with another set of sunken in M8 Bolts on both sides. The plates, in particular with all the loading, should then hold together pretty well.