Fixing ARC4 reflector

Okay, for a few days now, I've been slowly polishing an ARC4 reflector with some Brasso and a nice soft old diaper, in order to attempt to remove all the grooves in it when it was made.

FYI, it was machined, not very finely, and then overcoated with a urethane sort of coating, which smoothed in the roughness of the machining. No sputtered/vacuum deposited reflector coatings or anything.

Anyhow, half way through the process, I thought I'd get a shot of the sun in order to show the focal point, and how precisely it was made.

For your viewing pleasure:




Here is another shot which shows the machining marks better, note they are rather smoothed down now. Before removal of the clear coat urethane (the urethane hides alot of the machining (smoothing it over), and all the polishing I've been doing, it was much prominent:

Interesting!

how did You remove the LED and circuit board?
I thought the arc4s are potted?

Will You leave the bare polished aluminium surface
oris there a special coating you apply when polished?

I'll coat it with an industrial chemical protective coating.
Not sure which one I'll use, I've got several, like Chemglaze. It's too bad various coatings, urethanes, varnish, acrylics, polyurethanes, and such decrease the reflectance (causing more of the light to be absorbed), but it is alot better than having raw aluminum, which oxidizes very quickly and not noticeable to the eye when it does so. Only when it is really bad does it become quite noticeable.

If I had access, or had the equipment at home, especially for a fine flashlight that is in the multi-hundred dollar range, I'd do one of the special ultra-thin oxide overcoats, and it I was doing that, I'd do an enhanced Al, then Enhanced Silver, then a special oxide overcoat. Unfortunately, I don't have the equipment /ubbthreads/images/graemlins/frown.gif

Yes, they are potted. More details on the unpotting it are in other threads on cpf. If you want to look, search on my user name, and dig through them. There are some photos.

Nice work. I didn't realize how "rough" the machining is. Guess that's the nature of CNC.

CM

[ QUOTE ]
CM said:
Nice work. I didn't realize how "rough" the machining is. Guess that's the nature of CNC.

CM

[/ QUOTE ]


Nope, it's not the nature of CNC machining. It's just the way these particular items were machined. CNC just uses a computer and motors to control the motion of the cutting tool and/or work piece, instead of a person cranking dials to control the motion of the cutting tool and/or work piece.

Just out of couriousity, all the Arc4 Rev1 reflectors I've seen look pretty nice and smooth.
It seems that there was a major change in between Rev1 and Rev2.
Was it?

Different vendor making the parts, as events would seem to have it.