Orange peel vs. "roughing it up?"

Orange peel vs. \"roughing it up?\"

I really admire the beam quality produced by those orange peel finishes, but it got me to thinking. (Which usually leads me to a question or two.) /ubbthreads/images/graemlins/thinking.gif

For us hobbyists, if I machine my own reflector from some sort of nicely reflective metal, polish it but make no attempt to remove the swirls, scrapes, cut marks, etc., will those "machining artifacts" be enough to make the reflector smooth the beam in the same way the orange peel finish would? /ubbthreads/images/graemlins/confused.gif

Re: Orange peel vs.

I think the machining artifacts would not really do a good job of it. The orange peel effect is supposed to be truly randomised. Your machining artifacts would probably have some concentricity to it.

One trick I can imagine (which you will probably have to try to verify), is to use a medium to low grit emery cloth (suggest 100 grit) as the final step. Don't bother with polishing, just cut the reflector to shape. Then, rub it down with the emery cloth without worrying about removing all the swirls and scrapes. Move the cloth around as you spin the reflector. That should give you a nice orange peel effect.

Let us know if that works.

Re: Orange peel vs.

if you were patient, you could probably randomly attack it with a nail or other sharp object before repolishing...

Re: Orange peel vs.

In a word, no, I don't think so. Ok, so that was 5 words /ubbthreads/images/graemlins/grin.gif

I've had deep discussions with other members about this and have experimented with faceted, OP and etched diffusion planes and reflective surfaces and the conclusion we've come to is that shallow angle dispersion surfaces (such as gentle OP, bead blasting) result in much less loss due to inefficient scattering which is a major component of high angle dispersion surfaces (such as acid etching, sandblasting). I can't do the math but this is what appears to be the case empirically. I think this explains why SF use OP exclusively in their reflectors as opposed to facets, blasted or etched.

Wilkey

Re: Orange peel vs.

Thanks guys. Ginseng, that was an interesting explanation, and it does make some conceptual sense. I appreciate it! /ubbthreads/images/graemlins/thumbsup.gif

Steelwold, I don't really have the machining tools I'd need to make my own reflectors, but hopefully someday. Until then, I can always beg Roth, the Lathe Monster! /ubbthreads/images/graemlins/grin.gif