metal lens holder, reliable?

[Nii]

I can get them powder coated for free pretty much. Worth it?

[buffo]

Free powder coating? Hell yeah!

Truthfully, the corrosion issue is probably moot. But if nothing else, powder-coated optic mounts look great! They also reduce the risk of stray reflections, although with steel that is much less important than with aluminum.

Adam

Edit: One caveat: while powder-coating would be nice for optics, I would not powder-coat anything that you needed to transfer heat through, like a diode mount for example. Unlike anodizing, powder-coating is basically an insulator.

[Nii]

Cheers Adam.

15characters

[planters]

I can get them powder coated for free pretty much. Worth it?

Steel has a higher modulus (it's stiffer), so for a given size mount it will deflect less than brass or aluminum. Newport, for one, markets stainless as a high end option for some of its mounts. It has a modulus similar to milled steel and doesn't corrode, but it has terrible thermal conductivity and is nasty to machine. They are certainly manufacturing with flooded CNC equipment and obviously the thermal aspect during use doesn't bother them.

Stiffness is very important. Larger components can sag as they change position, but the most significant, practical effect is the spring back and deflection when adjusting. Ever tried to nail a flex-mount and a dichroic for beam combining? The far field spot moves from just inserting the hex wrench.

I would stay away from the powder coating as it is a compliant, organic coating on an optical support. It would probably be OK, but it might introduce some plastic deformation when squeezed down by mounting screws.

[buffo]

I would stay away from the powder coating as it is a compliant, organic coating on an optical support. It would probably be OK, but it might introduce some plastic deformation when squeezed down by mounting screws.

Excellent point, Eric. I hadn't considered the idea that it might allow some extra flex when tightened down. The severity would no doubt depend on just how thick the powder coat ends up being...

Adam

[kecked]

those sk rail mounts are aluminum. If all you want to do is hold a lens they work well. I have not seen any issues using them. They are easy to dill to the size you want as well. Think about compression is it does deform a lens. If I do it again I'd use a ring to hold the lens and glue it.

[Nii]

I agree, they look good. I've already ordered few of them. I'm thinking of cutting the top half of the circle off and make it like these holders http://www.ebay.com/itm/High-quality...MAAOSwHnFVk7n6
If you cut the top part where the hole is completely and get a flat surface then you end up with a good holder for square cylindrical lenses.

But such a holder is very easy to make from plain steel, alumium or brass bar with a circular saw and an ordinary big drill bit for the inset.