Film Advance Problem with Mamiya RB67

[PhxMedFormatPhotog]

This appears to be the day for Mamiya RB67 problems, so here's mine. Yesterday I took my Mamiya RB67 on a 600 mile road trip shooting photos on the Mogollon Rim and in the White Mountains, on a very beautiful cloudy and drizzly day in normally sunny Arizona. On the first roll, I had no issues; I got all 10 exposure. However on the second roll, when I went to expose the first frame, the shutter wouldn't fire. It wasn't locked and the dark slide was out. So I cranked the winder and it turned and advanced the film through a blank frame. No problems the rest of the roll. Today, I wanted to try out Arista EDU 200 speed film, and the problem was horrific. I got 6 exposures on the first roll, and only 5 on the second roll. At various times, the shutter wouldn't fire and I had to advance the film through a blank frame (ARGH!!!). Anyone have any idea what the heck is going on? (Oh, I developed the first roll of the Arista in D-76 1+1 and FWIW, the negatives look great; of course, I'll have to look at them under a magnifier when they film dries, and make some enlargements, but it seems like the Arista film might work out-and it's considerably cheaper than the TMAX I have been using.)

 

[shutterfinger]

Are we to assume the roll that was fine and the following one with one blank frame were different brands of film? Arista EDU is a high dye/ low silver film on a 3mil base in 120. Kodak and Ilford are 4.5 mil, Fuji is 3.5 mil base. The thinner base has caused spacing issues in some roll holders.
Do you use more than one roll holder swapping them out when reaching the end of roll or do you reload the same holder? I would carefully inspect the holder to body mounting for bent pins or debris in holes. Also inspect the holder shell for the same where the insert mates into it.

 

[WilmarcoImaging]

As shutterfinfer mentioned there may be a problem with the film back to camera body communication, which is via arms (or levers) in the body, which push pins in the revolving adapter. The body arms and adapter pins can both be either bent, loose or stuck. These symptoms can cause film advance issues. In the best case scenario, cleaning and slight bending will put things right. In other cases the camera body needs to be opened. Try dry firing the body with and without the film back and see if the pins hang.

I am not familiar with Arista film, but film thickness also sounds plausible as a cause.

 

[PhxMedFormatPhotog]

Thanks @WilmarcoImaging. @shutterfinger: The roll that was fine and the following one with one blank frame were both TMAX 400. Incidentally, I noticed that loading the Arista EDU was more difficult in that it did not want to stay on the take up spool and took a couple of tries to wind on. Also, when I poured out the D-76, it was green. Happy nearly St. Patrick's Day.

I'll check out the pins and arms and see if I can't find the problem there. Thanks for your suggestions.

 

[paul ron]

arista and fomapan have a green antihalation backing. prewash the film before souping and the green backing will wash away.

your film advance problem may be in the counter mechanism... its a signal arm and a wafer disk that need to be cleaned and readjusted. have you tried another film back to see if the problem is with the rev back?

the other cause may be the revolving back issue. those 2 chrome tits where the pins pop out... sometimes the pins get hung up because of dirt in the tits. many times people lay the camera on those tits not realizing it may cause damage. check the pins, they should move frictionless. if tgey are bent, straighten them. if its just hanging.. tiny drop of wd40 on each n excersizs them.

if the problem is in the film back, it will require a cla, or if you are handy its easy enough to do yourself. pm me for instruction?