The final machining (on the lathe that is) of the light is now complete:
The design of the light is perhaps best explained with reference to the following drawing:
With reference to the BOTTOM edge of the drawing, the small finger of metal immediately above the O-ring serves to limit the travel of the front glass. This ensures that (as the front bezel is tightened down) the glass itself can only travel ‘so far’ which translates to exactly 50% compression of the cross sectional diameter of the O-ring.
Again with reference to the BOTTOM edge of the drawing, the finger of metal protruding to the underside of the O-ring and alongside the front galss, serves to locate the glass yet allow it to move (slightly side to side in order to allow for thermal expansion) and also front to back (within the range allowed) as the glass is forced toward the rear by the bezel.
Water pressure once applied simply causes the O-ring cross section to extrude into an oval section with the maximum diameter touching the glass on the right side and the metal of the lighthead itself on the left.
The bezel is secured by four (4) stainless steel (M5) allen bolts into the main lighthead body.
Altough not detailed on the drawing, the MR16 globe is connected to the electronics via a ceramic socket and teflon coated wires which pass through the metal immediately below the switch section and into the rear housing.
The switch by the way is a Piezo Electric switch screwed into a milled and threaded M16 recess in the main body. The wiring for this switch also shares the transit hole from the front to rear compartments.
In the next post i’ll show the milling operation and also get into the cannister (not literally!) for the Lithium battery unit.