You talking about a bed camera, or a traveling head camera? The head camera isn’t working yet in software AFAIK. I don’t see how you could mount a bed camera on the gantry. Even if you put the gantry in a known position before taking a pic to use as the background, distance is needed to see an 8 ft wide bed. The camera would have to mounted on say a carbon fiber 4 point tripod (quadpod?), might have to be like 10 ft tall, and is going to jog around when in use, which is… odd. I would worry about the accuracy shifting with all that movement.
Not so much about mounting, but bed cam lessons learned for me:
With larger beds, you want to get the highest resolution you can. Currently that would be the Arducam 16MP (don’t get the autofocus version) https://www.amazon.com/gp/product/B09BCF6TGK/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
And the 2.8-12 varifocal lens https://www.aliexpress.us/item/3256801163627310.html?spm=a2g0o.9042311.0.0.45d463c0NFUByL&gatewayAdapt=esp2usa&_randl_shipto=US
The Arducam is an unusually large imager chip, the lens construction needs to match the imager size. The 2.8-12 is the one you need. Also you need this one with an IR filter as the Arducam had that filter in the old lens which will be removed.
And an M12 locking ring is needed for the varifocal.
The reason we want varifocal is you want to adjust for zoom so the FOV just reaches the corners and nothing else. Otherwise, you’re limited to only a few FOV lens options, and going any wider than you need potentially wastes a lot of resolution.
You are in a different situation, you actually could use a fixed FOV lens and adjust the mounting height until it covers the corners. But I doubt you’d want to. I don’t know how the mount would work (maybe on the ceiling? the machine’s not going to move) but the simplest would be the shortest mount possible and not mounting on an extension arm that gets it to an exact arbitrary distance from the bed as dictated by the lens FOV.