Anyone making their own lenses?

[Mr_Light]

I have been updating a bunch of vintage flashlights and have been replacing the lenses
with Acrylic cut out of sheets using a hole saw. The basic process is:
1. Choose a hole saw about 4mm bigger than the lens, use it to cut a hole through a
piece of 1" thick wood.
2. Clamp a piece of acrylic sheet (home depot window glazing...) between the piece of
wood you just cut the hole through and a piece of scrap lumber.
3. Remove the pilot drill from the hole saw and use the predrilled piece of wood as a
jig to drill the hole through the acrylic. Be sure to not to let the hole saw get hot
enough to melt the acrylic (when cutting several holes).
4. Pop the cutout from the hole saw and trim the edges with a file or razor knife. Peel the protective paper off and you are done.
If I get a drill press I won't need the wooden drilling jig.

 

[joedm]

I use glass from a cheap photo frame. Cut a square relatively the right size and then trace a circle with my glass cutter on both sides. Then trace lines out from the circle like rays of the sun on both sides. Using rubber gloves (and eye protection) use a pulling action holding the piece I want to keep with one hand and each section of rays with a pliers. Making sure not to clamp down too hard with the pliers as this will crush the glass. Tidy up edges with a file or stone. I've managed to cut lenses as small as 24mm in diameter.

 

[2xTrinity]

I use glass from a cheap photo frame. Cut a square relatively the right size and then trace a circle with my glass cutter on both sides. Then trace lines out from the circle like rays of the sun on both sides. Using rubber gloves (and eye protection) use a pulling action holding the piece I want to keep with one hand and each section of rays with a pliers. Making sure not to clamp down too hard with the pliers as this will crush the glass. Tidy up edges with a file or stone. I've managed to cut lenses as small as 24mm in diameter.

This raises an interesting idea -- I know that more expensive photo frame glass is actually anti-reflective coated. Buying that and cutting it into windows for flashlights may be significant cheaper than buying ultra-clear lenses that are pre-cut and coated. It may also allow AR coating in sizes that aren't normally readily available, such as larger windows for lanterns etc.

 

[TOOCOOL]

This raises an interesting idea -- I know that more expensive photo frame glass is actually anti-reflective coated. Buying that and cutting it into windows for flashlights may be significant cheaper than buying ultra-clear lenses that are pre-cut and coated. It may also allow AR coating in sizes that aren't normally readily available, such as larger windows for lanterns etc.

Nope the photo frame glass you are referring to is anti glare, might work if you want a smooth flood type beam though.

 

[TorchBoy]

I'm disappointed. I thought you might be making refractive lenses. :sigh:

 

[pmath]

I pop a hole saw with its pilot bit removed in the drill press. Bracing carefully against a fence I cut circles of acrylic until the drum of the say is full.

Unscrewing the drum from its mandrel in the press I screw a long bolt through the mounting thread which gently extrudes the dozen or so disks.

I then mount them between a couple of widgets that go in the chuck and tail stock of my lathe and wind the tailstock up nice and tight.

Gentle passes using a nice sharp insert produces beautifully finished edges.

I leave the paper on until the absolute last minute in assembly so as to avoid any grubby paw prints. Leaving paper on the inside surface produces a very diffuse light and a very grumpy assembler!

Cheers

Peter