I have a project where I'm mounting everything on a flat piece of sheet metal. I need to run the gpu via a riser cable and mount it with the back flat on the metal. Anyone have recommendations on how to mount it? Should I run some longer screws to the gpu backplate attachment points and then add like a rubber spacer in-between?
Forgive me: Any of these look useful? It really depends on the card/cooling. You could potentially do the backplate screw thing IF it doesn't affect waterblock seating. You could also pull the backplate and tap new holes if it's thick enough. With the plate off you can make sure the new mounting system doesn't allow a screw to pass too far through the plate. A good option is to make an angle bracket that replaces the original backplate. If there's a lot of real estate on the waterblock plexi, you can add something there. You could also make blocks with a groove in them that hold onto the edges of the pcb.
Blocks with a groove sounds like a neat idea if you could pull that off - they could screw in from the rear of the main "motherplate". If full-length blocks got in the way of the PCIe contact strip and riser cable (or whatever is being used), you could do thin U-shaped bracket-types at each end of the card.
I try to make the CPU cutout on the motherboard tray pretty much as large as possible. The only real boundaries are the PCI slot(s) and the rear I/O ports. The RAM will usually be at the front of the board, and can be considered another boundary, but some server boards do have it at the top edge running front-to-back.