Spun aluminum reflectors

[JimmyM]

Has anyone looked into spinning aluminum reflectors instead of machining them out of a large rod?
The process seems simple enough. A form chucked into a lathe and an aluminum disc bolted onto the end.
If this is more complicated than I seem to grasp, someone please educate me.
Or what about punching/stamping?

 

[Norm]

Jimmy, there is a local manufacturer of spotlights close to where I live and all his lights from about 100mm up to about 450mm (that's a huge light) have spun aluminium reflectors, the body of his lights are also aluminium, even I can hold his biggest light at arms length. He makes hand held and vehicle mounted lights.
Norm

 

[gadget_lover]

Punch and stamp require very careful design to avoid deforming / cracking / scratching the metal. I've seen cheap lights made that way and they have terrible reclectors. Most $1 lights will have either cast plastic or stamped metal reflectors.

As far as I can tell, spinning is about as easy as it sounds. I've seen videos of spinning aluminum and it's amazing to watch. The difficulty would lie in getting a nice parabolic shape to use as a form.

Daniel

 

[JimmyM]

A macine shop could make a steel parabolic form with a 1/2" - 5/8" shank for chucking in a drill press. Reflectors could be a lot cheaper and more plentiful than the several billet machined types available.

 

[gadget_lover]

You can make a fairly good parabolic form on a wood lathe with relative ease. A wood form is all that's needed for spinning, since the function of the form is to stop the metal from moving inward as you repeat the process further out towards the lip of the metal.

Daniel

 

[JimmyM]

I don't have a wood lathe for the making of the parabolic form or to do the spinning.
I DO have a 5/8" drill press though.
Really, I think these would be easy to make.
Then it would be the mere task of having them mirrored and stippled (read that last part with overwhelming sarcasm)