DIY Lenses?

[Powdersummit]

Well I've spent hours searching on the subject and I can't find much on making your own lenses. I've found some info on the math involved with lenses but not much on the manufacturing process. I would like to try and build some lenses on my own but I'm not sure which way to go.

The easiest way for me to do it would be to buy acrylic rod and machine it on a CNC lathe and then polish the hell out of it on the manual lathe. Is this possible? I haven't tried to turn acrylic on a lathe and I'm not quite sure how hard it is to work with.

If anyone has any experience making their own lenses I would appreciate any input you could give.

Carl

 

[Th232]

Can't give you much help on actually doing it, but I believe Saabluster moulds the aspheric lenses he uses in his DEFT (see his thread in the Custom Builders & Modders for more info). Can't remember anyone lathing their own though.

Definitely interested in the results if you get it working though.

 

[UnderTheWeepingMoon]

This thread might be of interest to you. Ra is an optics engineer and judging by his lights, he knows his stuff.

 

[RocketTomato]

Astronomy hobbyists make their own lenses for telescopes. I would look at one of their forums for advice.

 

[Powdersummit]

Thanks for the information thus far. I got on youtube and found this on "How it's Made"

http://www.youtube.com/watch?v=Am5wJUEiNAI

I'm thinking this is a bit much for what we're doing here but I think that Doing Acrylic rod on the CNC lathe and then polishing it in a second op is the way to go. A good tool and die machinist could probably do these on a manual lathe with a jig/fixture setup but I've got the technology at my disposal so I might as well use it. One of these days I might try and work out some fixtures so the manual guys could give it a shot.

I hope to be ordering some acrylic rod and do some brushing up on my optical physics here once I get over this damn head cold.

Carl

 

[PCC]

I had asked my cousin about doing something like this and he suggested using liquid acrylic instead of trying to turn acrylic rod. The reason is that it is much faster and easier to pour a casting as opposed to trying to turn something on the mill. Just saying...

 

[Powdersummit]

PPC, You started me searching on using "Liquid Acrylic" molding. I does look a lot easier than machining out each individual lens even though I could probably crank out the blanks fairly quick on the cnc lathe.

Well in my searching I came across tapplastics.com and a few other sites which has a clear polyester casting resin that looks like it's pretty nice and the prices aren't too bad. There are even videos on there to show how to use their products. (I'm not endorsing the site, just showing some useful information.) I don't know how well the material holds up to the weather but it might be worth a shot.

Carl

 

[wquiles]

Thanks for the information thus far. I got on youtube and found this on "How it's Made"

http://www.youtube.com/watch?v=Am5wJUEiNAI

I'm thinking this is a bit much for what we're doing here but I think that Doing Acrylic rod on the CNC lathe and then polishing it in a second op is the way to go. A good tool and die machinist could probably do these on a manual lathe with a jig/fixture setup but I've got the technology at my disposal so I might as well use it. One of these days I might try and work out some fixtures so the manual guys could give it a shot.

I hope to be ordering some acrylic rod and do some brushing up on my optical physics here once I get over this damn head cold.

Carl

Great video - thanks for posting

Will

 

[PCC]

PPC, You started me searching on using "Liquid Acrylic" molding. I does look a lot easier than machining out each individual lens even though I could probably crank out the blanks fairly quick on the cnc lathe.

Well in my searching I came across tapplastics.com and a few other sites which has a clear polyester casting resin that looks like it's pretty nice and the prices aren't too bad. There are even videos on there to show how to use their products. (I'm not endorsing the site, just showing some useful information.) I don't know how well the material holds up to the weather but it might be worth a shot.

Carl

My cousin used to work at Tap Plastics and that was why I asked him. I forgot this bit of info: if you do decide to cut lenses from acrylic rod then make sure you use cast acrylic as opposed to extruded acrylic. He said that the cast stuff mills much better than the extruded stuff, from his experience. I'll need to confirm this with him as my memory is a bit foggy.

 

[Powdersummit]

I think I'm going to shoot for the cast route first and see how it works. The last thing I want to be doing is polishing every lens from a turned blank. I can set the feed very slow for the final pass but the polishing would still take forever. With the cast route the lens is already pretty good and with a Jig for my wood lathe I could quick polish them up at home. The only thing I would have to make on the CNC lathe would be the original dummy lens which could be out of aluminum.

Carl