I have a Probotix Meteor CNC, and enjoy their design for it's aluminum extrusion 3060 t-slotted frame with nothing running inside the frame. Over the years I've had it I frequently find a flat hardwood part I've clamped to my MDF t-track bed doesn't cut through evenly all around. Even if I've just milled the bed flat using the CNC. Lately on a mission to tighten up the precision of my Meteor I realize a piece of hardwood with a little warp in it that I clamp flat to cut is warping the MDF bed rather than being pulled flat by the t-track clamps.
A few years back I made some bridges to span between the Meteor side rails to hold an assembled student project inside the frame so I could cut mortise arrays on the bottom for her legs. The bridges are an L shape made from 18mm BB ply and very stiff. They don't flex once bolted to the frame rails. In a moment of inspiration I wondered if 2 or 3 frame bridges, a little fancier than my initial two might be all that is needed for holding flat work down to cut.
So I've made 3 bridges in a T shape that have a single t-track down their middle, a row of holes for pegs to help align projects with, and cam levers on their ends to make it easy to release and move them up or down the frame rails for each project.
Two shown in the attached photo. I use a 3rd when clamping longer boards that might droop or bow up between two.
4D
A few years back I made some bridges to span between the Meteor side rails to hold an assembled student project inside the frame so I could cut mortise arrays on the bottom for her legs. The bridges are an L shape made from 18mm BB ply and very stiff. They don't flex once bolted to the frame rails. In a moment of inspiration I wondered if 2 or 3 frame bridges, a little fancier than my initial two might be all that is needed for holding flat work down to cut.
So I've made 3 bridges in a T shape that have a single t-track down their middle, a row of holes for pegs to help align projects with, and cam levers on their ends to make it easy to release and move them up or down the frame rails for each project.

Two shown in the attached photo. I use a 3rd when clamping longer boards that might droop or bow up between two.
4D