I’m using L-girder benchwork, with fairly large areas of flat ground (since most everything prototypically should be around 15 feet above sea level, if that). This would normally entail risers with cleats on them, so I can drive all of the screws from below. The main reason to use L-girder benchwork is the ability to move risers & joists as needed, and that is hard to do if you drive screws in from the top.
I dislike using cleats on the risers — it’s not that hard but it can be kind of fiddly.
I also have the luck of being able to use most of my joists as the riser as well, since most of the lumber I used to make the joists was cut at the same time so they’re the same height.
Time to dig out the tools. I have a jig to make these nifty pocket holes, and they work beautifully for driving the screws from below. This joist is a bit smaller than most, so it’s attached to the leg and not the L-girder.
The jig holds the board securely and has a guide for a special bit. Everything is set “just right” for the pocket hole to be drilled and a pilot for the screw placement. A bit of sawdust is created, and you’re ready to drive the screw and hold the joist to the plywood.
I placed several pockets to attach to the boards above. No part of the screw protrudes above the surface of the plywood when they’re driven.
I think they’ll all be out of the way as I need to drill switch throw holes in order to place the switch motors, but if not, I’ll just move the joist. That is the beauty of the whole L-girder system after all.
The jig is from Kreg and can be ordered online or from your favorite local hardware store.