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Graflex RB-Auto 3x4 -- quick lens board question
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keshlam
Joined: 21 May 2021
Posts: 38
PostPosted: Sun Jul 25, 2021 4:52 am   Post subject: Graflex RB-Auto 3x4 -- quick lens board question

In my camera, the lensboard is secured with a diagonally-sliding metal piece, much like the Graflex-back film carrier.

In Theory, then, it would seem that it should dismount the same way -- slide that retainer out of the way, then tilt slightly until the top is clear, then lift up slightly to clear the pocket at the bottom.

Right?

It's resisting the tipping-forward step. I'm guessing this is just be "it's been decades since anyone even tried and it's a bit stuck", but I'm reluctant to push harder until I'm sure there isn't some trick that I'm missing.

(More new-owner nerves... just making sure my sanity check won't bounce.)
45PSS
Joined: 28 Sep 2001
Posts: 4081
PostPosted: Sun Jul 25, 2021 5:48 pm

Slide the lock bar to the unlock position.
Lift up on the lens board until the bottom will clear then swing the bottom out then the lens board down to remove the top.
keshlam
Joined: 21 May 2021
Posts: 38
PostPosted: Sun Jul 25, 2021 7:16 pm

If I look through the diagonal slot, I don't see anywhere to raise the lensboard until after it has been tilted out. And it doesn't seem to want to tilt out far enough to be lifted. So I'm still confused.

Can I assume that the screws in the corners of the lower bracket are just holding the bracket in place, and don't penetrate the lensboard?

45PSS
Joined: 28 Sep 2001
Posts: 4081
PostPosted: Sun Jul 25, 2021 7:41 pm

See https://graflex.org/RBGraflex/#InterchangingLenses section for the RB Auto.
I may have stated the directions for the Telescopic Graflex.
keshlam
Joined: 21 May 2021
Posts: 38
PostPosted: Sun Jul 25, 2021 9:09 pm

Yeah, the RB instructions say release slidelock, tilt out, lift up.

That tilt step doesn't seem to be working for me; not tilting far enough.

I _must_ be missing something obvious.
45PSS
Joined: 28 Sep 2001
Posts: 4081
PostPosted: Sun Jul 25, 2021 9:36 pm

Does the top edge of the board have a bevel? If so the board was put in upside down.

Loosen the screws holding the bottom retaining strip 1 to 2 turns to gain more clearance.
keshlam
Joined: 21 May 2021
Posts: 38
PostPosted: Mon Jul 26, 2021 2:02 am

Not seeing a bevel. But since the rb-auto lens board swings out at top rather than at bottom, the board might still be in upside down, or it might be someone's homebrew that they didn't bevel.

I'll keep looking...At least I have confirmation that it shouldn't be fighting me, so something is odd.
.
keshlam
Joined: 21 May 2021
Posts: 38
PostPosted: Mon Jul 26, 2021 3:01 am

Figured it out:

The inner barrel of the Heliar 18cm f4.5 just barely fits into the bellows opening. There is simply no room to tilt or lift it; it seems one _must_ remove the bottom bracket. The inner lens housing shows some scrape marks top and bottom, so apparently I am not the first to wrestle with it.

If there had been sliding latches on _borh_ sides, that would let it pull straight out. Wonder if anyone ever tried to retrofit that. Since this camera can do some upward shift there might be enough room, and it feels like it might actually make sense.


Well, now I know. Not that I expect to change lenses any time soon; this is mostly about understanding and perhaps doing a basic cleaning of the camera. I guess another limitation of the 3x4+ model is that there's just less wiggle room and a bigger shoehorn was needed when mounting this lens.



In the process of figuring this out, I discovered that one of the screws holding the lens flange to the lens board has gone AWOL, leaving an open hole thru the lens board. It looks like it _may_ be in a place where it wouldn't be a light leak, but if I can close it up...

Any chance one of you fine gentlemen could tell me what size that screw is supposed to be (or at least likely to be), so I can try to fit a replacement without (further?) stripping that opening? I could try removing and matching one of the others but if it came to that Iight just tape that hole and call it good enough for now.


Ah, old equipment. There's the factory spec, there's the standard modification, and then there's whatever the last people to work on it did to solve the problem of the moment... and from the customer's point of view, the last guy who touched it is responsible for whatever it is.
45PSS
Joined: 28 Sep 2001
Posts: 4081
PostPosted: Mon Jul 26, 2021 3:28 am

That's a non standard lens for that camera. Another way would be to unscrew the rear cell from the lens barrel then remove the board. It will be a tight fit to get ones hand in the body with the mirror up and curtain at O.

The flange for that lens likely uses a #2 to #4 flat head wood screw about 3/8 inch long. Remove a existing and measure iit.
45PSS
Joined: 28 Sep 2001
Posts: 4081
PostPosted: Mon Jul 26, 2021 5:17 am

What is the serial number of your camera? Its on the view door behind the view hood, usually at the top of the door.
keshlam
Joined: 21 May 2021
Posts: 38
PostPosted: Mon Jul 26, 2021 2:26 pm

SN 95231.

Unscrewing the rear element: Hm. Can investigate that next time.

Matching the screws: Yeah, if this is a nonstandard setup gifs know what they used, so that makes sense.
45PSS
Joined: 28 Sep 2001
Posts: 4081
PostPosted: Mon Jul 26, 2021 6:31 pm

http://piercevaubel.com/cam/catalogs/1915graflexlp592.htm pages 26 & 27.
95231 - 1916.

https://www.boltdepot.com/Wood_screws_Slotted_flat_head_Brass.aspx
keshlam
Joined: 21 May 2021
Posts: 38
PostPosted: Mon Jul 26, 2021 7:20 pm

Thanks for the lead re brass hardware. That may be useful for other projects too.
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