Arduino test bench

This is a flexible test bench for arduinos and solderless bread board. The extension parts bolt on while the accessory boards are designed to have units placed on via 2.8mm pegs. The peg array is a grid 10mm center to center. TT motor mounts have pegs and a slot for a Velcro strap.
The bolt holes in the test bench are mad to have heat pressed m3 threaded inserts installed. I put recesses in for the m3 panheads. The motor mounts and accessory boards are at a 45 deg angle for ease of use.
I plan to design more units to hold parts to the accessory board. Another planned addon is a set of drawers to go under it for wires and components. I will also be working on a version that is printed in section and then assembled for smaller printers.