Taking aperture ring off a 5x7 B&L barrel lens

[Jim C.]

I've been trying to figure out how to get the dang aperture ring off to clean it,
cleaning the foggy front cels wasn't much of a problem, I was able to take
that apart with a little PB Blaster and patience to clean between the cells,
but the aperture ring has got me, f4.5 - 5.6 is really stiff and seems to me to need a
good cleaning and possibly a little lube, I see no screws at all on the ring externally,
or internally, there is a impression of something that might be a screw but it's no where near where the aperture ring is.
So has anyone taken one of these apart ?

[Dan Fromm]

Jim, I had the same problem, asked about it on graflex.org. Les Newcomer kindly send me a jpg showing how to take the barrel apart. I've posted it at https://skydrive.live.com/redir?resid=8D71BC33C77D1008!323&authkey=!APfXBCvyT7HnqR0

If you can't download it, please complain and send me your e-mail address in a PM.

Good luck, have fun,

Dan

[Tim Meisburger]

Cool! I haven't felt the need to take mine apart, but if I ever do, that's a bit of knowledge that will save a ton of frustration.

[Tracy Storer]

Dan, thanks for posting that one.....I haven't encountered that arrangement, most manufacturers employ a (thankfully) much simpler barrel / aperture ring style.

[Jim C.]

Mystery solved ! Thank you Dan ! And thanks to Les Newcomer, where ever you are !
I suspected that there was a band, but I thought it was threaded like my Seroco, it's probably seized up
on there with finger gunk, gonna give it a PB treatment overnight and see if it slides off.

[Oren Grad]

And thanks to Dan from here too - I've got a gaggle of B&L tessars in barrel, and this is bound to come in handy!

[Jim C.]

Ok, I skipped the PB treatment, the band does slide off with some effort, probably warmed the schmutz enough from me
pulling on it for a few minutes, one thing that my lens has is that the groove on the aperture ring does not line up
with that tiny screw, a slotted set screw actually, I had to remove it to get the ring off.
A caveat about that tiny screw, work over something that will catch it if you drop it because it's about 4 threads
in length, so if you drop it you'll never find it again.
96038
That speck at the bottom of the picture is the set screw.

[Jim C.]

Another note about that set screw, in mine, it's steel so a magnetized jewelers screw driver
helps a lot in getting it back in.

Having cleaned decades of gunk off the barrel and ring the aperture ring rotates nice and smooth
but a little too smooth, and to me too loose, I put the thinnest schmear of lithium grease on the
barrel and it's better but not the velvety feel I was hoping for.
I've been searching around for a grease or wax that will dampen the ring
and came across Nye damping grease, it's used for focusing movements on lenses.
But it's kind of spendy, any suggestions on a workable substitute ?