To provide a test bed for a few ideas, I used a SF turbo head and a battery tube from an old SF
baton light kit. I made a threaded LED pedestal that mounts securely in the front end of the
battery tube. Not shown in the images below, there is a milled "key way" the length of the
pedestal that provides for no rotation of the flood reflector around the pedestal. The mating
threads on the battery tube that would normally allow it to be screwed onto the turbo head were
removed. The head is now held in place on the battery tube via two set screws that have machined
follower pins on their end. These pins are screwed down into a groove that was machined into the
battery tube behind the sealing O-ring. This allows the head to rotate freely about the battery
A cylinder with an external lead screw helix serves as a flood reflector when deployed. This flood
reflector will freely slide up and down on the pedestal but will not rotate as explained above. There
is a lead screw pin that is installed in the rear threaded section of the turbo head and this pin
extends into the bore of the head and drops within the relieved helix on the flood reflector. When
the parts are assembled, a clockwise rotation of the head on the body draws the flood reflector up
until a stop set screw in the reflectors bottom end contacts the rear face of the turbo head. A
counter clockwise rotation of the head drops the reflector down and out of the path of light from
the LED to the turbo reflector's surface. Since these pictures were taken, I have bored out the
reflector more than shown and it now actually serves as a host to various reflector elements I
might try placing within it. So far, a simple cylinder that has a beveled step down close to the LED
die that has been bead blasted has provided the best, flood beam with just a hint of artifacts.
Although the resulting flood beam pattern is what I was after, the current element is likely
considerably less efficient than other alternatives yet to be made or tried.
Above the flood reflector is withdrawn and not in effect and in the picture below, it is extended and
depriving the turbo reflector from view of the LED. You can just make out some of the helix
reflected in the turbo reflector's surface.
With the simple flood reflector shown which is literally nothing more than a block from light
contacting the reflective surface of the turbo head itself, a very useful and even flood beam
replaces the piercing and intense spot beam from the turbo. I selected the turbo as a host because
in addition to having it, it has wasted reflective surfaces below the focal point which are of no use
to the LED. This allows for the large bore for the flood reflector without impairing or effecting the
useful portion of the turbo reflector itself. The LED is a Lux III driven at 917 mA (DownBoy). A
lux reading of the turbo reflector at one meter yielded 2600 lux. With the flood reflector extended,
the lux dropped to 24 lux.
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