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ImageMaker
Joined: 20 Jun 2006 Posts: 93 Location: North Carolina
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Posted: Thu Jun 21, 2007 1:57 am Post subject: Adapt-a-Roll 620 -- loading, film counter, and friction |
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I've just acquired a *beautiful* Adapt-a-Roll 620 (4x5) in a trade deal, but I'm having trouble with the frame counter. I downloaded the instructions (from somewhere on graflex.org, I believe), and loaded the back according to those instructions, but the frame counter wasn't clicking before I saw the paster and closed the darkslide and was very slow starting up afterward; I think I wound two, maybe two and a half frames before it got to the 1 after setting the start mark as soon as I saw the paster.
I had tested with a bare backing paper first, and found there wasn't anything like enough tension (with a 120 supply spool) to operate the counter, so I'd taped in a foam friction pad that I thought would contact only the supply roll; however, partway through the roll that pad came loose and got rolled up into the takeup (and should be interesting to extract when I load that roll into the reel in the dark). The counter continued working after that occurred, but I only got 5 or at most 6 frames (I could hear/feel the film tail come off the supply roll, then the backing come off on the next advance), which I think was due to the counter not starting to "click" when I first closed the dark slide and set the knob to "S".
What am I doing wrong? Do I need to lubricate the cam on the friction roller that operates the pushrod (or some other part of the mechanism, like the carrier for the pawl that advances the counter wheel), find another way to add friction to the 120 supply, or have faith and load according to instructions? Or something else???
Also, has anyone converted the takeup clutch in one of these to rotate the opposite direction (by cutting an opposite notch for the spring and roller), so the film winds "right side out"? Doesn't look as if it would bollix up the feed to have the film go to the top instead of bottom of the takeup spool (it'll run around the supply a little, but that'll just ensure tension and it'll be backing to backing)... _________________ Is thirty-five years too long to wait for your first Speed? |
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Dan Fromm
Joined: 14 May 2001 Posts: 2120 Location: New Jersey
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Posted: Thu Jun 21, 2007 9:53 am Post subject: |
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Two thoughts.
Speak to the entire frame counter mechanism with powdered graphite. Then foof it out.
I have an AAR that's been modified to take film up right side out. And others that haven't been modified. The modified one has slightly worse, I sometimes think, film flatness at the take-up end of the gate. So I use the others. Since I send my E-6 films out for processing, I have to respool exposed ones on to a 120 spool before sending them to the lab. That's what a changing bag is for.
Cheers,
Dan |
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ImageMaker
Joined: 20 Jun 2006 Posts: 93 Location: North Carolina
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Posted: Thu Jun 21, 2007 2:33 pm Post subject: |
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I process my own film, so saving the 620 spool isn't a big deal, it's just annoying to have to go through a bunch of rigamarole to seal the roll, and I really don't trust the seal after having to fold the tail of the roll backward far enough to get the seal strip to reach. I greatly dislike respooling where it's not necessary (unavoidable when converting film to 127 or 828, though); almost all the 620 cameras I own accept a trimmed 120 supply, and I never let loose of a 620 spool any more (though long term, takeup conversion is desirable, so I don't even have to carry 620 spools, my Reflex II will never get that conversion -- virtually impossible to convert the takeup, and supply is fine with trimmed 120 -- and neither will any of my 620 box cameras).
I'm much more concerned about operation of the counter; I'll try blowing some dry graphite into the pivots and put a tiny dab of the teflon grease I use for focus threads onto the cam, and see where I wind up.
The takeup modification I plan will be reversible -- that is, I'll cut a second notch in the original Bendix plate, and if I don't like the operation of the holder after modification it'll be the work of ten minutes to take the knob off and move the spring and roller back to the original notch. If you take the knob off yours (uses a 5/64 hex driver on the setscrew -- careful you don't drop the spring or roller) you'll likely find that's the case there, too. _________________ Is thirty-five years too long to wait for your first Speed? |
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Dan Fromm
Joined: 14 May 2001 Posts: 2120 Location: New Jersey
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Posted: Thu Jun 21, 2007 3:55 pm Post subject: |
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Actually, I think that all you'll have to do is turn the notched plate upside down. And you're right, care must be taken not to lose the one-way clutch's roller or spring. |
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ImageMaker
Joined: 20 Jun 2006 Posts: 93 Location: North Carolina
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Posted: Thu Jun 21, 2007 4:35 pm Post subject: |
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Dan, I had the knob off, and I think there's a bearing sleeve attached to the plate that goes through the body casting. Won't know for certain if they're attached until I find a screwdriver that a) fits the screws, and b) will fit inside the compartment while c) letting me get a grip good enough to actually turn the screws, which probably haven't been moved since the unit was assembled a minimum of about 40 years ago. I *might* be able to improvise something with a 1/4" box wrench and driver bit from my interchangeable screwdriver set -- except I don't think I have a 1/4" box wrench. _________________ Is thirty-five years too long to wait for your first Speed? |
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ImageMaker
Joined: 20 Jun 2006 Posts: 93 Location: North Carolina
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Posted: Mon Jun 25, 2007 4:45 pm Post subject: |
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Okay, follow up on this (so it gets into the archives).
I blew graphite into the friction roller bearings and down behind the toothed counter wheel, sanded off the corrosion on the operating cam (at the end of the friction roller), then applied a dab of Permatex Superlube teflon grease to the cam and another to the contact surface of the pawl tooth (that drives the toothed counter wheel). I think that's got it; it takes much less effort to manually operate the counter via the friction roller now, and when I loaded a roll of film the counter started clicking well before I saw the leading edge of the paster, and seemed to be advancing about the correct amount for each click.
While I had the thing open, I also took out the Bendix plate. I was correct; I couldn't just turn it over to reverse the operation, because there's a collar (that acts as a bearing for the drive key shaft) that goes through the body of the AAR. Instead, I used a Dremel cutoff disk and small files to cut a matching, but opposite notch and put everything back together; the advance now turns the opposite direction and will roll the film the normal way. Dan, I'm now certain your reversed AAR can be un-reversed in about ten minutes, if you want to bother; you just have to take the knob off, reassemble the spring and roller in the notch for the opposite direction, and reinstall the knob. And a correction -- it's a 1/16 Allen key, not 5/64 as I posted earlier. The marks in my (very cheap) hex driver set aren't very well aligned with the actual key storage slots... _________________ Is thirty-five years too long to wait for your first Speed? |
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Dan Fromm
Joined: 14 May 2001 Posts: 2120 Location: New Jersey
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Posted: Tue Jun 26, 2007 1:17 pm Post subject: |
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Thanks for the update. |
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ImageMaker
Joined: 20 Jun 2006 Posts: 93 Location: North Carolina
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Posted: Thu Jun 28, 2007 4:31 pm Post subject: |
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Well, after running a test roll through the cleaned and lubricated Adapt-a-Roll 620, I seem to have the opposite problem -- that is, instead of the backing slipping and giving huge, erratic frame spacing, I now have almost no space between frames, even overlaps of a couple mm.
Given it's not practical to introduce a controlled level of slippage, what I expect will be needed is to build up the diameter of the friction roll in some fashion; I'm thinking of coating it with rubber cement, perhaps two or three layers. That will avoid making the roller slip on the backing, but will very slightly increase the amount of film that rolls past with each revolution of the roller; if I add half a millimeter to the roller diameter, I'll add about 6 mm interframe spacing (at four revolutions for a 6x9 frame), which should be just about right.
I'm guessing this is due to a change in the backing paper since the AAR was made; modern films use a thinner backing, and sometimes show some effect on frame spacing with counter mechanisms that rotate the takeup by a fixed angle, as well (because those depend on spool diameter to set advance distance, and diameter builds up more slowly when the film/backing sandwich is thinner). Even a quarter mm difference in total thickness could cause overlaps where there were originally narrow interframe spaces... _________________ Is thirty-five years too long to wait for your first Speed? |
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Dan Fromm
Joined: 14 May 2001 Posts: 2120 Location: New Jersey
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Posted: Fri Jun 29, 2007 9:53 am Post subject: |
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What you suggest has been done on one of mine. |
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Murray@uptowngallery.org
Joined: 03 Apr 2002 Posts: 164 Location: Holland MI
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Posted: Fri Jul 13, 2007 7:57 am Post subject: rubber coating for spool |
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I bought some Plasti-Dip to try on bellows after unsatisfactory attempts with black nail polish.
The Plasti-Dip comes in aerosol also.
It has 5 solvents. They say you can dilute it somewhat with xylene.
I didn't have any, but had a couple of the other solvents. Acetone resulted in a lumpy looking, not very smooth mix that acts like it doesn't even want to wet the sides of a glass jar I mixed it in.
Elmer's Unstick (formerly Seal's Unseal), is a heptane naptha blend for removing adhesive from photos etc. Naptha is one of the Plastic-Dip components IIRC so I tried that & it results in a nice smooth mix.
Both the acetone-diluted and the Unstick-diluted results looked the same and seemed to have same adhesion on a razor blade (fingernail test) when dry.
This stuff always dries out before I use an entire 12-or-so ounce can.
IM, email me off list if you want to try my diluted blend.
Murray _________________ Murray |
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ImageMaker
Joined: 20 Jun 2006 Posts: 93 Location: North Carolina
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Posted: Fri Jul 13, 2007 1:06 pm Post subject: |
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Murray, I'm pretty sure the USPS wouldn't want you shipping that stuff; nor would UPS or FedEx be very happy handling it. OTOH, this past weekend I took some "friction tape" -- sold to protect wiring from friction where it goes around corners and such, it's cloth tape with a rather tacky surface on the back and adhesive similar to electrical tape -- and wrapped a single turn onto the roller at each end, and in the middle. The diameter buildup is just about exactly what I wanted, it'll come off readily if needed (and even the adhesive residue will come off with naphtha or Goo-Gone), and the roller was turning even with the light touch of the backing while I still had the roll in one hand threading through the frame gate and starting the tongue into the 620 take up spool.
I'll know if the spacing is right after I finish the roll, but the tape thickness should be adding just under half a millimeter to the roller diameter, which in turn would add about 6 mm to the spacing -- which should be just about perfect. _________________ Is thirty-five years too long to wait for your first Speed? |
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