On Thu, 13 May 2021 16:05:27 +0100, PeterC
wrote:

On Wed, 12 May 2021 23:20:30 +0100, T i m wrote:

or can adjust once you have them?

You can with many of them with a hot air gun.

I have tried that with many glasses but some are plan plastic arms (no
wire) and so you have to hope they are made out of some sort of
thermo-plastic. I have got some pretty hot with a hot air gun and they
didn't seem to give or take a new set.

I got my thermoset ones just right with a hot air gun. Tried it first on a
pair of ready readers with almost identical frames and it worked.

Good plan.

Made sure that the hot air got nowhere near the lenses. Just a guess, but
the lenses might have a bit of inherent stress from the forming and even
relatively low temperature might 'relax' them.

Good point.

That's how they adjust them at the optometrist.

Ha! Mine tried a glorified, fixed, hair dryer. I did point out that it
wouldn't work and stopped her from getting the lenses in the airstream.

So called 'professionals'. ;-(

Made the mistake of having flat metal arms on my latest pairs - can't bend
it of course and the hot air ain't going to work!

Well, you can get things pretty hot with even cold air, as NASA know
with heatproof tiles. ;-)

Possibly a MAPP torch
would, or oxy-propane - that's a take arm off specs job.

And what if you have plastic covers over the metal ends (that don't
come off)?

I have a small hot-air gun I use for heatshrink tubing that is pretty
hot but gives a fairly well focused column of air. If I want similar
with even more heat, then the heat gun on my SM reflow station should
do it. ;-)

If I can find my GD glasses, I'll check out all those fitting numbers
and see if it's that they don't fit me (and if I can adjust them) or,
without having the hooks that go right round your ears, they are just
too heavy for my usage / expectations (eg, expecting them to stay put
like these all plastic readers generally do)?

Cheers, T i m