Gregg MacPherson Posted April 7, 2022 Share Posted April 7, 2022 (edited) [Edit: any added notes will be in brackets, just so] In the 80s, there (were) several ACL Is in use in Australasia ex Australian Broadcasting. People using them for documentaries, short films, music videos. They had the small original motor, the supposedly "non orientable" viewfinder (you orient the VF then rotate your head), English 400' mags, Angenieux zooms. I had one then. There is a lot of misinformation out there, some on otherwise quite legitimate websites, so I mean to question and clarify that...Please correct me if I make any factual errors. The Eng 400' mag design... Referring to the pic above..The Eng mag is the same design as the French except for the take up system [and some other small differences]. There is no friction drive belt to the take up spindle. Instead there is a take up arm with two rubber tyres on the brass wheels that ride on the take up roll, emulsion in, so riding on the cell side. The design gives a low current draw, on par with the original 200' mags, so was suitable for the small motor on ACL I. The mechanicals...There are gears that give the offset to the take up arms drive capstan. From there a toothed rubber belt goes to the rubber tyres spindle. I'll talk on longevity and servicing in a later paragraph. There is a large circular protrusion on the feed side that is the tension adjustment for the take up arm. The platter always seems to be 200'. Maybe the 400' ones did not exist yet. No matter, a properly serviced Eng 400' mag take up roll tracks true, even without anything touching the sides of the roll. The pressure plate was a single piece design, so the whole length of the plate is pressing the film onto the gate. Early French mags are the same. [ -The French mag doors seal just by having a double step on the edge. The Eng mag doors have a single step with a grey rubber seal mounted in a shallow chanel. The same grey rubber looks to be used for the Eng pressure plate light seal. Another difference, French/Eng is that the French mags have screw adjustments for the guide shoe clearance adjustment.] Servicing the Eng 400' mag So I crossed the line (sorry Dom) and did a full tear down on two mags. I had done a partial service on one previously, but this was a full disassemble, clean, repair/replace and lube. I didn't know anyone who serviced these. Bruce at Aranda was no longer into it when I talked to him a while ago. Maybe Les Bosher does, maybe Paul Scaglione at Visual Products (VP) could, but shipping is really high relative to the value of the mag. I don't know if Covid lockdown was the excuse, but I used generic synthetc lubricants. We still don't have a list of lubricants for the ACL... For the untrained, inexperienced person there's about as much work in overhauling one of these mags as in reconditioning an old engine. It needs the right skill set and intellect and a lot of patience. The ball bearing in the drive sprocket hubs was replaced. I think most of the mags here except the brand new 200' ones have some stiffness developing in the drive sprocket bearing. Replacing was detailed, but yields to patience, straining my memory now, a puller was improvised to remove the brass hat shape at one end and a blind bearing puller was made so I could pull the ball bearing out. My friend made one for me, but the ones you can buy should work ok. The likely service intervals for different parts (sporadic rather than everyday use)... After 40 years everything needs CLA. Normally, the oblique drive shaft bearings is down to the longevity of the grease. Once or twice in a mags lifetime...Plain bearings that are loaded, a shorter interval, they will be checked whith the camera's CLA. The drive sprocket has a plain bearing and a ball bearing. The shielded ball bearing, replacement once or twice in it's lifetime. The plain bearing will need clean and lube more often. The friction is easy to assess at CLA time. Obviously, plain bearing surfaces that are loaded and rotating need care with checking at CLA time. A good calmera tech who's seen the mag before will save you money. The toothed rubber drive belts for the take up arm seem fine after 40 years in the Auckland climate. Other climates may shorten their life. One can often find fine pitch belts, or have them made, but I think parts from wrecks will cover this need if it ever arises. The little rubber drive wheels may have a life span of a few years. I had some made, cost me $1 each, needing a tiny bit of hand finishing on the edge. The light seal at the pressure plate and mag doors (look like the same sectional shape) seem ok for the life of the mag unless someone damages them. The, English seals, grey, a hollow tube or D section, look better to me than the French pressure plate seal, black, solid maybe. One can buy a 2mm diameter hollow rubber section dirt cheap on eBay and replace if needed. Paul S at VP thought so For the pressure plate seal I'll wait and see if it gets around the corners without a crease. For the mag doors I think the bend radius is fine and a crease in the corner is ok. Current draw, French 400' vs Eng 400' vs 200' mags, test results, facts vs myth... Years ago I tested the current draw on my ACL I with loaded 400' mag, 25fps, and got 1A. It was regularly serviced by a good tech. I did have him switch to sub zero grease around then for a short time, and I can't remember if I did the test with that grease in. Temperature for test, guessing 22degC. The only camera available for the test now was an ACL II with latest motor, basically almost brand new, and with the tuning for noise at VP the amps can go up a bit. Current draw with no mag, 1A. So the amps raw data may be high and misleading, but the comparative will be meaningful. I'll show that, the % change in current draw...Another issue, one that may compromise the test...I chose from three French mags the one with least friction. Mags lightly used, no service history. The fingerometer tells me that friction is slightly higher than the brand new 200' mag. 200' mag...0%...is the baseline. French 400'(Pat 2)... +39% Eng 400' (mag3)...... +6% Eng 400' (mag2)...... -6% (Edit: Took about 5 readings over 400'. There was a small increase in current draw as take up size increased. Summary is taken from max values) So I hope this illuminates the issue about the English 400' mags and the small motor. Of course, we haven't yet measured the current draw on a serviced French mag yet. I could have done that before I sold a couple to Heikki a short while ago. Heikki, if you get the urge, I'm happy to help set up the experiment. Otherwise, I will eventually overhaul the French mags here. Untill we do, test a freshly serviced French 400' mag, it is possible that the French mags are OK on the small motor. It will need to show the same amps as a 200' mag to convince me. I knew some guys that blew their ACL I motor with a French mag. I bought their second camera, with English magazine. Cameras were regularly serviced back then, but I don't know if their French mag was. Other myths about the English 400' mag... I think I read on Ermut's website that the Eng mag was prone to film jams. This is a complete myth and jams will only happen with really gross lack of service. I can illustrate with my own example...Bought an ACL I with Eng mag about 1984. The camera body was regularly serviced, but the mag not. The rubber take up tyres were slipping on the wheels. Tyres didn't look old, but maybe the wrong size ID. Result was poor tracking on the take up and sometimes a "loose wind" going to the lab. Young and not yet clever, I fixed it by improvising guide bars on the mag face and door (platters are 200'). Years later I just replaced the tyres and it tracked perfect and tight. That myth needs to disappear.....!! Final thought, make sure your loader is properly familiar. English 400' mags have a spring loaded column on the feed side. Threading around that grossly scratches the roll. My arri-familiar but new to ACL producer once helped out and did that for me (horrific scratches on the film). Gregg. Edited April 21, 2022 by Gregg MacPherson syntax, spelling, more info 1 Link to comment Share on other sites More sharing options...
Gregg MacPherson Posted April 7, 2022 Author Share Posted April 7, 2022 Forgot to include... Pic shows the take up arm in the retracted position. To engage, there is a round button on it's left end, simultaneously press and rotate that, holding the arm so it releases gently. The door won't close while the arm is retracted. Link to comment Share on other sites More sharing options...
Premium Member Dom Jaeger Posted April 7, 2022 Premium Member Share Posted April 7, 2022 10 minutes ago, Gregg MacPherson said: So I crossed the line (sorry Dom) and did a full tear down on two mags. I had done a partial service on one previously, but this was a full disassemble, clean, repair/replace and lube. I didn't know anyone who serviced these. Great job Gregg! Please don’t think that I’m against people doing this sort of thing themselves. I mean I’ve written detailed blog posts showing people how to disassemble cameras and perform certain service procedures, and I often give people service or lubrication advice (for what it’s worth) on this site. You’re careful and diligent, exactly how you should approach it. Of course some things are probably best left alone, because they need special knowledge, tools or instruments, but you know that. It’s the cocky people who think pulling precision cameras apart is no big deal that I find problematic. Your information here is great, I’ll be referencing it next time I have an ACL in front of me! Link to comment Share on other sites More sharing options...
Gregg MacPherson Posted April 7, 2022 Author Share Posted April 7, 2022 (edited) 1 hour ago, Dom Jaeger said: Great job Gregg! Please don’t think that I’m against people doing this sort of thing themselves. I mean I’ve written detailed blog posts showing people how to disassemble cameras and perform certain service procedures, and I often give people service or lubrication advice (for what it’s worth) on this site. You’re careful and diligent, exactly how you should approach it. Of course some things are probably best left alone, because they need special knowledge, tools or instruments, but you know that. It’s the cocky people who think pulling precision cameras apart is no big deal that I find problematic. Your information here is great, I’ll be referencing it next time I have an ACL in front of me! Hey Dom, I didn't really think you would mind. I was making a joke. I've seen your Cinetinkerer website with the Arri II teardown. I didn't make adequate notes or pictures when overhauling the mags, I realize that's a mistake now, it could save someone else some time. If you do have an English 400' mag job and are stuck I can try and remember. Maybe I should write it all down. Some important parts are common with or very similar to the French mags. I do have an Eng 400' mag here for parts, may help. And a few spare "rubber tyres". So, can we cautiously pin a flag on Melbourne, for our global map of techs who service ACLs..? Sweet. Last time this came up (some time ago) you were a bit cautious because you were less familiar with them. I always thought that a good tech familiar with SR and Aaton could bone up easily on ACL if he could have Q&A with an expert occasionally. Paul Scaglione recently said that he might help like that, if I read him correctly. There may be someone in Australia. Five years or so ago I was talking on the phone to a youngish sounding tech at one of the rental companies about servicing for Aaton and ACL. He was only familiar with Aaton, but a senior tech (I think in the same Co) was good with ACL. Can't remember their names, or the Co. Hopeless, I know... Anyway, there's a bit of a posse on the Eclair sub-forum trying to find suitable techs, you may have noticed. Still hoping to visit my sister near Melbourne, it which case I could drop off a set of S16 superspeeds, hoping you might check the focus lube on some or all, and swap the mounts out to PL. I'll PM about it later on. Cheers, Gregg. Edited April 7, 2022 by Gregg MacPherson forgot the spare rubber tyres Link to comment Share on other sites More sharing options...
Gregg MacPherson Posted April 7, 2022 Author Share Posted April 7, 2022 (edited) Some pictures from the drive sprocket bearing replacement... Note that there are plastic spacer washers at either end, shown in the parts drawing as same, but they measured different thickness, so measure yours when they come out. The last picture is just in thanks to Rogi, who made the blind bearing puller on a Sunday...some pics follow in the next post. I improvised a puller to remove this brass hat by drilling 3 holes in a washer, 3 screws and a spacer tube that sat around the brass hat. The knurled knob for the drive sprocket (not shown) is fixed to the shaft with a screw. Before removing shaft from the assembly carefully debur the screw detent on the shaft. Edited April 7, 2022 by Gregg MacPherson trying to add pics Link to comment Share on other sites More sharing options...
Gregg MacPherson Posted April 7, 2022 Author Share Posted April 7, 2022 (edited) More pics. First one, the blind bearing puller. We gave it a single split on the end, like a clothes peg. The llast one is the puller maker, Rogi... Edited April 7, 2022 by Gregg MacPherson Link to comment Share on other sites More sharing options...
Premium Member Dom Jaeger Posted April 7, 2022 Premium Member Share Posted April 7, 2022 2 hours ago, Gregg MacPherson said: There may be someone in Australia. Five years or so ago I was talking on the phone to a youngish sounding tech at one of the rental companies about servicing for Aaton and ACL. He was only familiar with Aaton, but a senior tech (I think in the same Co) was good with ACL. Can't remember their names, or the Co. Hopeless, I know... Probably Graham Jones at Lemac in Sydney, who was factory trained on Aatons and other cameras. But please confirm with him first. 1 Link to comment Share on other sites More sharing options...
Heikki Repo Posted April 7, 2022 Share Posted April 7, 2022 1 hour ago, Gregg MacPherson said: Some pictures from the drive sprocket bearing replacement... Note that there are plastic spacer washers at either end, shown in the parts drawing as same, but they measured different thickness, so measure yours when they come out. The last picture is just in thanks to Rogi, who made the blind bearing puller on a Sunday...some pics follow in the next post. I improvised a puller to remove this brass hat by drilling 3 holes in a washer, 3 screws and a spacer tube that sat around the brass hat. The knurled knob for the drive sprocket (not shown) is fixed to the shaft with a screw. Before removing shaft from the assembly carefully debur the screw detent on the shaft. This quite useful. I have cleaned and relubed now one French 400ft mag, but I didn't take them fully apart nor did I go for the ball bearings as I couldn't get the information necessary for this operation from anyone I asked. Link to comment Share on other sites More sharing options...
Gregg MacPherson Posted April 7, 2022 Author Share Posted April 7, 2022 If the ball bearing is free then you could just leave it. The friction feeling could come just from the plain bearing, oui. Cant remember if my ball bearings were shielded one side or both. The side visible when looking down into the hub was shielded. I may still have the bearings and can check. The parts drawing shows no shield, but.... Link to comment Share on other sites More sharing options...
Gregg MacPherson Posted April 8, 2022 Author Share Posted April 8, 2022 Just a clarification... The photo above showing the drive sprocket assembly, its from the Eng 400' mag. The drawing is from the Eng 200' mag. The sprocket drive hub on the Eng 200' mag, like the French 400' mag, has a V pulley machined into it for the take up "belt". The Eng 400' mag has instead a gear pressed on. That transmits to an idler or intermediate gear, then the take up arm spindle. Cautionary note...how easy it is to screw up... One of the sprocket drives, the detent in the shaft had burs from some prior rough treatment, that I did not properly debur. Fairly sure this damaged the brass bearing surface and maybe I damaged the shaft too. Lucky I had a spare mag wreck. A good example of not being observant and patient enough. The whole drive sprocket used to be a spare part. That would be quicker... Gregg. Link to comment Share on other sites More sharing options...
Gregg MacPherson Posted April 8, 2022 Author Share Posted April 8, 2022 (edited) Servicing the "guide shoes" and their mounting plate.. The assembly of little ball bearings (each with a lip), hold the film against the drive sprocket. Called guide shoes in the drawing. The tech for my ACL I (Bruce Pierce) had a trick of cleaning the bearings (there's a gap at the inner edge of the shields), and immersing them in oil, then somehow must have drained them enough so they didn't drip. Maybe he had a trick to speed that up. I tried this on one of the Eng 400' mags which was not as super frictionless as the other. Those bearings normally should spin fast and free with a flick of your finger tip. Anyway, was a bit of work with disassembly and all but easy enough. Draining did take a while. Aimed some air at it, think that helped. The mounting plate for the entire guide shoe assemblies..On the French mags I have there are tiny screws to adjust the gap between the guide shoe ball bearings and the drive sprocket. On the English 400', none. I did notice a tiny bit of wiggle room on the mounting screws for the plate, so I improvised by using two layers of film to set the gap, then tightening the mounting screws. I don't know, maybe a new plate would position perfectly without that. Edited April 8, 2022 by Gregg MacPherson more words Link to comment Share on other sites More sharing options...
Gregg MacPherson Posted April 9, 2022 Author Share Posted April 9, 2022 (edited) Mags falling off the camera..fact vs myth. The pertains to French mags as well, I believe, unless they have a difference in the geometry of the retaining mechanism that I didn't notice. If the mag retaining mechanism has too little spring force then the mag can fall off if the camera gets a big vertical jolt. Happened to me once jumping off a truck, holding just the top handle (zoom mounted, battery on belt). Mag landed ass first on very compacted, fine gravely road and was fine. Some writer(s) on the web describe this as if it's a generic design flaw. The retaining mechanism was I'm sure not changed with the intro of 400' mags, so perhaps the designers are at fault. Does anyone know if there were any changes to the latch or springs in the history of ACL? (excluding the obvious latch cover) Adjusting the spring force I found quite easy, by shimming under the catch tooth plate on the mag, #310 in Eng drawing below. Can't remember how thick the shiming, maybe 3 or more layers of tinfoil from a coffee can or something. If I added too much I think the latch wouldn't quite open, so that puts a constraint on it. If all mag fronts have the same dimensions (I wondered) then you have to shim all the same. A better method might be to modify or replace the release lever spring. See the UK parts catalogue for a drawing. So, fact or myth? Gregg. Edited April 9, 2022 by Gregg MacPherson more fact, less myth Link to comment Share on other sites More sharing options...
Heikki Repo Posted April 9, 2022 Share Posted April 9, 2022 Thanks Gregg! I have had my 400ft mag drop off when I forgot to put the clothespin to secure it. Unfortunately, the mag was loaded (everything on the supply side) and as a consequence of the hit, the spool axle support was slightly bent and the mag was stuck. Furthermore, I had just received the mag back from service from Bernie. I asked if he had a replacement and he told me no; he just hammers them back to shape. This was the first repair job I did on my ACL (mag). I wasn't fully able to hammer it back, but with a combination if hammering and adding a spacer in the other side I was able to solve it. Now I have replacement axles, so I'll return it back to original specs. Anyway, the risks of dropping the mags are real, so doing this "upgrade" could really be worth it. One just has to remember that some ACLs might have stronger spring force than others, so if the mag is modified, it might not be easy to remove on a different ACL. Link to comment Share on other sites More sharing options...
Gregg MacPherson Posted April 10, 2022 Author Share Posted April 10, 2022 19 hours ago, Heikki Repo said: ...some ACLs might have stronger spring force than others, so if the mag is modified, it might not be easy to remove on a different ACL. Yes, makes me think that the spring force will vary, and may get weaker with age/use. The lock spring MIN106 if not replaceable could maybe be tweaked a bit, but haven't tried, don't know if it will tolerate it. If irreplaceable, be careful. I never tried a clothes peg. That would be a 1/2 clothes peg with those in NZ. I heard of one guy whos mag fell off and it just shattered into pieces... Link to comment Share on other sites More sharing options...
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