would heating and shaping also work for the chap that wanted some lenses for a pair of MkIIIa goggles?

above was supposed to be in the thread with Alex describing making parts out of ferrero rocher boxes!

In theory I guess although I dont have a pair of MkIIIs so im not too familiar with them. Saying that, the Ferrero Rocher boxes are a stiffer plastic than the (original) lenses are made from, so I'd look at sorting another material. But if you had an original to make a pattern from, i dont see why not..

Thanks for thinking of me but i was after something a little more realistic. The theory is the same i guess, 2-3mm plastic cut & curved to shape.

Seeing the lenses in my MkIIIa's I can't shake the feeling these aren't shaped at all.
I would make a good (flat) lens and let the frame do the forming.

Cheers, Toine

Toine,

I have two pairs of MkIIIa's and a pair of MkIII's I have had the lenses out of all of them and they all show to some degree a curvature. The ones in the 38 and 39 dated RAF mkIIIa's are curved more than the ones in my 42 dated RCAF MkIII's. These lenses are quite thick so if using a replacement of equal thickness I would think they would need to be shaped to the frame. In my opinion not shaping them would run the risk of damaging the frames.

Interestingly there is also a curved very thin blackend brass fillet that comes out with the lens, I wonder if it is there to help keep the lenses in shape?

...and I still have the material which was not easy to find. It's a very close match to the original, especially in thickness, but naturally it's clear unlike the aged originals. The lenses are handmade and although I haven't made a pair for several years I could knock out some more if there's any interest. I just need to find the time. Click on my name and email me if you are interested. 

They are curved to closely match the curve on originals and that is one of the tricky bits to acheive as it's a complex curve and if it's not right they won't go into the frames- it's a bit of an art actually and I usually mess up a lens or two in the process, which is a bugger because all the shaping work (cutting, filing and sanding) needs to be complete before they are shaped.

The fit is usually a little tight but they shouldn't affect the frame. You do need to make sure the metal shim is located correctly as well- I suspect it's there to assist with sliding the lenses into place- a bit like a washer.

Here's a shot comparing an original on the left to the new on the right.

This is a complete pair

A fitted example.

 

Really super work there.

Hi Andrew, i can't seem to sent you a PM, would it be possible to contact me at; [email protected] with regard to your MkIII lenses?? Thanks, Kerry.

Will do Kerry, and i'll check my profile to see if i'm accepting them. cheers