Locking positioning pin

A position adjustment mechanism comprising:

• a first component, the first component defining a track aperture extending in a first direction and a plurality of receiver cutouts spaced apart along the track aperture wherein each of the plurality of receiver cutouts has a second direction width that is larger than a second direction width of the track aperture, the second direction orthogonal to the first direction;
• a second component selectively fixable relative to the first component by a locking positioning pin assembly, the locking positioning pin assembly comprising:
• a shaft attached to the second component at a first end of the shaft, the shaft protruding through the track aperture, the shaft having a second end opposite the first end and the shaft translatable in the first direction within the track aperture to allow translation of the second component relative to the first component in the first direction;
• a nut threadably engaged with the shaft and rotatable to thread along the shaft between:
• a closed position relatively closer to the first end of the shaft;
• and
• an open position relatively further from the first end of the shaft;
• a knob rotatable about the shaft to cause rotation of the nut;
• and
• wherein:
• when the nut is in the open position, the knob is translatable relative to the shaft and the nut to allow a plunger to move between a disengaged position relatively further from the first end of the shaft and an engaged position relatively closer to the first end of the shaft;
• when the nut is in the closed position, the plunger is forced into an engaged position and is prevented from moving into the disengaged position due to abutment of one or more features of the knob with one or more features of the nut;
• and
• when the plunger is in the engaged position and the plunger protrudes into one of the plurality of receiver cutouts, abutment of the plunger with one or more edges of the one of the plurality of receiver cutouts prevents relative movement of the first component and the second component.