BigTreeTech GTR mounting frame with stepper cooling duct

My SK-Tank kit came with a BigTreeTech GTR control board. I needed to make a frame to mount it on the back, with a duct to provide cooling air to the stepper drivers.

This design is not compatible with the GTR expansion board, nor with directly mounting a Raspberry Pi to headers on the board. However, the FreeCAD files are provided, and it might not be too difficult to shift the mounting block around to get the ductwork out of the way of at least the the expansion ribbon cable.