Sultan Thahir Posted March 18, 2015 Share Posted March 18, 2015 Hi all,I'm going to try my best to describe my troubles in hopes that someone will understand what I'm talking about.Basically when I run film through my Arri 2b, the film (or more specifically the perforations) hit against the small knob/gear that says "Fette (Grease)".I don't think it is damaging the film too much, but it just doesn't seem right.Here's a photo of the knob/gear I am talking about. I have a shoot coming up soon, so anyone with insight please let me know ASAP.Thanks Link to comment Share on other sites More sharing options...
Mark Dunn Posted March 18, 2015 Share Posted March 18, 2015 As long as your loop looks like the one in the manual, and runs true and isn't pulling short, contact with the perfs won't affect the image area. Things are pretty tight in there. Link to comment Share on other sites More sharing options...
Sultan Thahir Posted March 18, 2015 Author Share Posted March 18, 2015 Okay great. The loop does look like that after it's loaded into the camera body, but after I roll the motor, it does tighten up and makes contact with the knob. Link to comment Share on other sites More sharing options...
Premium Member Aapo Lettinen Posted March 18, 2015 Premium Member Share Posted March 18, 2015 I don't know that particular camera well but sounds like a mag issue to me (used 35-3 and 16bl which have similar type mags), if the lower loop tightens then the film must be slipping on the take-up side sprocket. have you tried with different magazine, did it do the same with it? if so, then it could also be the camera side gear which drives the magazine Link to comment Share on other sites More sharing options...
Premium Member Aapo Lettinen Posted March 18, 2015 Premium Member Share Posted March 18, 2015 there may be too much tension on the take-up side (wrong friction adjustment) which causes the film to slip. you should see this on perforations if you use a dummy roll for testing. you can also upload a video and post it here (remember to include audio) , it should be easy to spot the issue then Link to comment Share on other sites More sharing options...
Premium Member Tyler Purcell Posted March 18, 2015 Premium Member Share Posted March 18, 2015 There is a clutch on the take-up side which is probably damaged. It takes a few milliseconds for the pulley to get up to speed and during that time it's designed to take up fast and then slip. Most likely that little mechanism isn't dropping to it's "slip" position fast enough. You should be able to feel this by putting tension on the take up pulley and starting the camera. It will probably jerk right out of your hand. Link to comment Share on other sites More sharing options...
Premium Member Dom Jaeger Posted March 19, 2015 Premium Member Share Posted March 19, 2015 The sprocket roller in the mag throat keeps the loop size constant, it's very unlikely to slip and change size because of a tight take-up clutch, the perfs would have to rip. More likely the loop is too small to begin with, or the film is being laced in the gate at the wrong perf. Always manually inch the camera over a few frames before rolling to check that things are correct. Link to comment Share on other sites More sharing options...
Charlie Peich Posted March 19, 2015 Share Posted March 19, 2015 Sultan, I agree with what Dom says on this. Is your loop size correct? It is important to maintain proper loop size: 54 perforations for both the 400 ft and the 200ft magazines. What size mag were you using, 200 ft or 400 ft? If it's the 400 ft size, which mag do you have, the 35-II B mag with the belt drive on the mag, or the later 35-II C / 35-3 (called the 480ft Color magazine) version with the gear drive? If you have a 400 ft 35-II B mag, the cloth belt acts as the clutch, it is easily adjustable, but I doubt it would have enough torque to pull the film and strip the perfs. If the tension is too tight, you would hear a 'clicking' or buzzing sound from the film when the camera is running. Usually the cloth belts got loose, and wouldn't take up tightly. At least that was my experience with the mag. 35-II B mag, 54 perf loop take-up cover removed The yellow arrow points to the adjustment spring thats puts tension on the take-up belt. You can use either of the 2 posts to increase or decrease tension. Read pages 42 through 51 of the repair manual I sent you! A tension gauge is recommended to adjust properly, page 48 of the manual. If you need a new belt, I don't know where you would find one. Arri stopped supplying those decades ago. It would be easier to get a 35-II C mag with the gear drive than to find a belt. (UNLESS, Dom has some in his parts drawer) (I do have some new/old stock 200 ft belts). The thing is, with the gear drive magazines, you then have to deal with the felt clutches... another story. Charlie (Greetings Dom!) Link to comment Share on other sites More sharing options...
Sultan Thahir Posted March 19, 2015 Author Share Posted March 19, 2015 The loop size is correct. Can you elaborate on what you mean when you say the film is being laced in the gate at the wrong perf? Link to comment Share on other sites More sharing options...
Charlie Peich Posted March 19, 2015 Share Posted March 19, 2015 I believe Dom is referring to the upper loop size. That loop should be 15 perfs. Link to comment Share on other sites More sharing options...
Sultan Thahir Posted March 19, 2015 Author Share Posted March 19, 2015 Okay I think this is a little more complicated than I thought. I will try to post a video tonight. Thank you all! Link to comment Share on other sites More sharing options...
Sultan Thahir Posted March 19, 2015 Author Share Posted March 19, 2015 Thanks for you help everyone, it was in fact the upper loop that I've neglected. One last question that's unrelated. After I load the mag in the dark, do I have to place the loop into the film gate in the dark as well, or is that something that can be done in the light? Link to comment Share on other sites More sharing options...
Premium Member Aapo Lettinen Posted March 19, 2015 Premium Member Share Posted March 19, 2015 you can load the mag to camera in normal light, you will only expose the visible loop. the film rolls have to be loaded to the mag and exposed film removed in dark Link to comment Share on other sites More sharing options...
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