So I wanted to try a 27L reflector but I was too late to see the 27LT offering, and besides, an Aleph compatible version would allow some fun with swapping out various light engines. But how to make one without a metal lathe available?
I played a hunch and bought a few parts. First a McR 27L Reflector from the Sandwich Shoppe and from LightHound a GP Tactical Bezel and an E2C Adaptor.
Once I had all the parts, the first order of business was to reduce the diameter of the largest step of the 27L until it was an easy sliding fit in the bezel. You may want to do this step second, see my error below. This was done by chucking the reflector (using the smallest step) in the wood lathe on slow speed and using a file. This went fairly fast, there's only a few thousandths that needed to be removed.
The next step is fitting the middle step of the 27L into the top of the E2C. This was a bit more involved. I drilled down a bit (about 3/8") into the E2C using a 15/16" Forstner bit in the drill press. I used some fitted wood jaws in the vise and a wood pad below to avoid marring the E2C. The Forstner bit proved easier to center and less prone to grab than a twist drill bit would be and survived not much worse for wear. Even with lubrication though, the drilling generated a lot of heat.
Unfortunately, 15/16" isn't quite big enough. DOH! Can't go back to the lathe with the 27L, The edge of the large end is now too thin to chuck without bending, and my filework tapers a bit. Can't chuck on the small step, too close to the jaws to work. If I was smart, I would have fit the reflector in the E2C first. A combination of reaming the hole and removing material from the 27L eventually allowed the 27L to slide into the E2C so that the largest step of the 27L rested against the end of the E2C.
At this point I put the lense, o-ring, and bezel ring (non-tactical, if it matters) on the bezel and screwed the E2C with reflector in it up into the bezel. There was about a 1/8" gap between the E2C and the rear of the bezel and there was almost a perfect amount of space in the E2C between the reflector and the end of an E series battery tube to fit an Aleph LE. Unfortunately, there was maybe about 1/4 turn of threads left in the E2C for the LE to engage. If I had more energy and patience, I would have bored out the chamfer in the E2C at the end of the threads and pressed in an aluminium bushing which I could have tapped to match the threads in the E2C. Instead I ground about 1/16" off the end of the E2C which moved everything back a bit. The gap between the bezel and the E2C is now only 3/32" or so, (easy to fill with an o-ring), the LE has about a full thread to support it, and there is now a small gap between the E2C and the battery tube, nothing that can't be filled with a slightly fatter o-ring on the tube.
So there it is, a 27L Aleph compatible head you can build for about $68 in parts in a moderately equipped shop. If you have a well equipped shop with a metal lathe you could do a better job than I did. I would much rather have bought it ready made from the Shoppe (hint, hint), but with the Aleph series being discontinued...
Having used (played) with it a little, the beam with a 5 watt Lux is like a tight version of an L4, with a bit of a "donut hole", and the beam with a 3 watt is as advertised, a tighter version of the McR 20 beam.
I played a hunch and bought a few parts. First a McR 27L Reflector from the Sandwich Shoppe and from LightHound a GP Tactical Bezel and an E2C Adaptor.
Once I had all the parts, the first order of business was to reduce the diameter of the largest step of the 27L until it was an easy sliding fit in the bezel. You may want to do this step second, see my error below. This was done by chucking the reflector (using the smallest step) in the wood lathe on slow speed and using a file. This went fairly fast, there's only a few thousandths that needed to be removed.
The next step is fitting the middle step of the 27L into the top of the E2C. This was a bit more involved. I drilled down a bit (about 3/8") into the E2C using a 15/16" Forstner bit in the drill press. I used some fitted wood jaws in the vise and a wood pad below to avoid marring the E2C. The Forstner bit proved easier to center and less prone to grab than a twist drill bit would be and survived not much worse for wear. Even with lubrication though, the drilling generated a lot of heat.
Unfortunately, 15/16" isn't quite big enough. DOH! Can't go back to the lathe with the 27L, The edge of the large end is now too thin to chuck without bending, and my filework tapers a bit. Can't chuck on the small step, too close to the jaws to work. If I was smart, I would have fit the reflector in the E2C first. A combination of reaming the hole and removing material from the 27L eventually allowed the 27L to slide into the E2C so that the largest step of the 27L rested against the end of the E2C.
At this point I put the lense, o-ring, and bezel ring (non-tactical, if it matters) on the bezel and screwed the E2C with reflector in it up into the bezel. There was about a 1/8" gap between the E2C and the rear of the bezel and there was almost a perfect amount of space in the E2C between the reflector and the end of an E series battery tube to fit an Aleph LE. Unfortunately, there was maybe about 1/4 turn of threads left in the E2C for the LE to engage. If I had more energy and patience, I would have bored out the chamfer in the E2C at the end of the threads and pressed in an aluminium bushing which I could have tapped to match the threads in the E2C. Instead I ground about 1/16" off the end of the E2C which moved everything back a bit. The gap between the bezel and the E2C is now only 3/32" or so, (easy to fill with an o-ring), the LE has about a full thread to support it, and there is now a small gap between the E2C and the battery tube, nothing that can't be filled with a slightly fatter o-ring on the tube.
So there it is, a 27L Aleph compatible head you can build for about $68 in parts in a moderately equipped shop. If you have a well equipped shop with a metal lathe you could do a better job than I did. I would much rather have bought it ready made from the Shoppe (hint, hint), but with the Aleph series being discontinued...
Having used (played) with it a little, the beam with a 5 watt Lux is like a tight version of an L4, with a bit of a "donut hole", and the beam with a 3 watt is as advertised, a tighter version of the McR 20 beam.
