20230503 Update to sliding mount

Using 140mm gobilda D shaft and clamping method instead

For clamping

• what screw + size 

• #6 hardware too big, m3 will work

Added upper clamp to limit how far it slides down (keep it outside of bottom camera FOV) 

could stop it right there so it stays outside bottom camera FOV 

Use other camera to see if gripped or not 

Not sure if this drops low enough to grip without legs getting in the way though

Other solution, move gripper further back on sub

Or just have it drop completely down and intersect with bottom camera fov + use bottom camera to as primary way to determine if gripped or not