I installed the 90 degree camera from lightburn on my K40. I chose to mount it using a thingiverse 3d printed mount from the top near the lid handle. It’s a sturdy mount and holds the camera well. All in all I think I could’ve even purchased the 80 degree camera.
Like other have mentioned, calibration has been a bit rough. When it comes time to calibrate the left side of the laser bed the camera seems a bit out of focus and I repeatedly get errors saying it cant find the pattern or if it does manage to find the pattern the score is pretty dismal in the .50 range. In the end I complete the calibration but have to use the x and y offset in the camera tab to get it close. Without the offset I’m about 1 mm off on the X axis and 3.5mm off on the Y axis. Its serving its purpose so far but I’d like to get it more accurate. As it stands I still need to do a quick test cut to ensure my piece will turn out correctly. I’d like to be able to stick a tile or coaster on the bed and trust that the design I intend to etch is going to end up where I want it.
So far though, it needs fine tuned but I like the concept.