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  • #31
    Originally posted by Jesse Crooks View Post
    I don't know if there are any substantive differences with the Christie badged version, but it looks about the same. You mount it on the bracket so the holes go over the roll pins, and then tighten the captive screw (looks like the screw itself is missing from the Christie). There are some slight difference in the face plate (see the recessed hex screws and what look like holes for small roll pins on the bottom of the Christie). Hopefully someone who has used both can tell you if they fit the same bracket.

    The Christie cleaner pictured is the original design with a chain drive. The Kelmar cleaner pictured is the updated design with a gear drive. The gear drive spins slightly faster, which is slightly more desirable, however if you are looking for the media to advance a little faster you can also just use a "fatter" takeup core via an aluminum spacer or a 3D printed core.

    That being said, for many years Kelmar made a version with the same chain drive design as the Christie cleaner above. The only way to tell without pulling the cover off is to look at the thickness of the drive shaft that the main drive wheel is mounted on. The fatter shaft (like the Kelmar above) is the geared version and the skinny shaft (like the Christie above) is the chain drive version. Note that the Kelmar chain drive versions have a tapered center piece in place of the big handle on the Christie, where the Kelmar gear drive is flush with the edge of the main drive wheel flange.

    Either type of cleaner will mount on the same bracket.

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    • #32
      Originally posted by Ryan Gallagher View Post

      Other than the abrupt start/stop issues noted... the enclosed goldberg one we have produces a far far better wind than our kelmar bench does. I've often wondered if it would be even better to just put a couple bypass rollers on the projector and just use the projector itself to rewind, especially when aiming for re-shipping back on cores. Our best winds are definitely fresh off the projector, but they are tails out of course.
      The Kelmar is a very basic rewind table that is built well and is a workhorse. That being said, there is nothing special about it and it's not the greatest thing ever.

      The auto-stop arm roller may give a better wind because it is laterally offset a tiny bit from the reel flange. You would be better to mount a fixed roller to pass the film around though, as the auto-stop arm bounces up and down. Regardless, it's all about flange binding. You want the film to very gently just drag slightly against one of the flanges.

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      • #33
        Originally posted by Ryan Gallagher View Post
        Aside, one of our recent 70mm prints had a full 3in "fold back" onto itself mid reel found during pre-inspection. We were scratching our heads as to "how does this even happen"? But Brad's cautions about rewinders that perform the abrupt stop.... now I think I understand how it happened. If there was a tension variation anywhere in the reel, the abrupt stoppage would cause all that mass to want to carry on around... and it did, folding the film back on itself mid reel. Yikes.
        They were using a Kelmar type of table. As I tried to explain previously, if you take a reel that is tails out and rewind it so it becomes heads out and do not touch the clutch adjustment during the rewind, when you are finished the heads out reel will have the tail end wound looser than the head end. This is a problem for all the cinch scratch reasons I tried to explain earlier, but it's the table almost all theaters have, so you just have to work with it.

        That being said, there is always a point during the rewind where you can develop a "fault line" on a Kelmar table because the tension is increasing throughout the entire rewind. That is the point where such a slip and fold mid-reel could and does sometimes happen.

        Our rewind tables have electronic backtension and a dancer arm roller that controls the current being fed into the supply spindle's motor. The end result is we select a winding tension and as the rewind is happening, the electronic clutch is slowly decreasing the amount of backtension so every single wrap in the reel is wound with exactly the same tension. That's the right way to do it.

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        • #34
          Our kelmar table does need a little TLC. It's a bi-direction one but we generally avoid the reverse because the clutch tension on the normal forward motor it would have to free-spin seems to high to avoid cinching. We've never adjusted or investigating servicing it in my term, it's always been "is what it is" to everyone up here since the old-timers left. So definitely overdue.

          The guide roller certainly helps. Spindles are straight-ish but have certainly been bent and repaired a couple times. We are also on our last two 35mm spindles that have not had the key wear to the point of coming loose (no doubt from the booth abusing the auto-stop features at higher speeds). Wear to the spindle hole on our house reels (or house reel condition in general) is probably as much to blame as any bench issue for less than ideal rewinds. We've sorted them by flange/warp quality, but I have not involved spindle hole wear to that quality ranking yet.

          The split reel approach is good advice, however that requires picking up some better condition (less warped) split reels. As is we mostly avoid the ones we have due to condition and favor a plastic split reel when the need arises.

          Is it worth having the spare 35mm kelmar spindles re-keyed? Or if they have obviously been bent and straightened in their past lives, just retire them and try to get new ones from kelmar?

          If we get the kelmar bench tuned up i'll take into advisement retiring the Goldberg auto. Though it certainly was handy on the occasional print we need to ship tails out. Two rewind stations utilized for each reel as they came off the projectors.

          That raises a question. If it's so important to monitor rewinds per this whole conversation, do most people save them until after the film? Or rewind as you go? Because we staff the booth with 2 for film screenings (one to juggle all the DCI/preroll/backup stuff)... we maintain the option to have monitored rewinds regardless of when we do it. Obviously this only applies to locales where shipping heads out is the norm.

          If you needed to ship tails out on cores, would you use a good condition split reel for takeup? Or stick to house reels and do the extra rewinding steps?

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          • #35
            Originally posted by Jesse Crooks View Post
            What's wrong with the wind you're getting with the Kelmar table? That's worth some investigation before you try to develop an alternative. Is the tension set correctly? Could there be an issue with the clutch or the take-up? Are the spindles bent? Are you having issues all the time, or could it just be an issue with specific prints rather than with your table?

            They're workhorses but do require maintenance. The felt pads need to be replaced with some regularity. At longer intervals the clutch plates wear down. Belt wear and alignment can be an issue. The wiper brush for the variac and the motor brushes will eventually wear down. I've had to replace the bearings on three different feed heads in the last couple years, and most of the tables in service are probably as old or older than mine.

            Clutch issues are easiest to detect by taking an empty reel and slowing spinning it. Does it turn evenly, or does it drag at certain points in the rotation? The take-up issues I've experienced have been most noticeable at low speed. The film might bob, or power might cut out periodically, etc.

            If the table is working correctly but you're having trouble with a specific print (usually acetate that's beginning to experience structural issues) there are a few things you can try:
            • Wind it onto a split reel before winding it onto the shipping reel. Split reels allow the least lateral movement (less room to wander because the flanges are closer together) and when you feed from the split reel to the shipping it will register against the inboard flange of the shipping reel, giving you a smoother wind. You don't want this lateral offset between reels to be extreme, but the difference you get between standard reel types is fine. If it shipped on cores, even better. Running between two split reels will always get you the smoothest wind when the film is misbehaving.
            • Try inverting the emulsion orientation. Some reels will wind terribly in one orientation and perfectly in another. Obviously you should aim to return prints as received or as specified by the lender when possible, but preventing damage in shipping is far more important. Just notify them and tell them why you had to return it that way.
            • For really bad prints, using the auto-wind roller can help you get a good wind. Don't go crazy with it (run it a responsible speed and don't actually walk away from it). Just use the roller to give you a steadier wind.
            In terms of using the projector to rewind for return shipping, that sounds like a lot of trouble to do something the wrong way. If you have a problem with the Kelmar table just do it the old fashioned away and rewind by hand. It will take half the time of running it through the projector, without the risk and additional wear.

            Projecting onto shipping reels should be avoided for a number of reasons, and I'm guessing that if you're running 70mm rep titles you're probably running archival prints. If so, the lending agreements usually expressly forbid projecting on shipping reels. I would particularly avoid using the projectors for rewinding if you're taking up on cores, since your clutch tension will be too high for the 2-3" hubs that prints commonly ship on.

            Move the Goldberg to the lobby... it's only good as a display piece. Or a boat anchor.


            So did a bit of service to the kelmar station today. Could definitely justify a couple new 35mm keyed spindles (extended key if we are buying), as well as maybe belts. Not bad but you can feel some vibration still on the motor acting as the clutch at certain speeds (after servicing).
            1. Noted that one mount had definitely shifted slightly out of alignment, and they had slightly different offsets from the table edge. (Corrected, and added fender washers where I could.
            2. Opened them up, cleaned (fair bit of belt shed inside).
            3. Checked belt pulley alignment, nothing wrong there.
            4. Checked belt tension.
            5. Swapped the lesser used motor brushes from the reverse motor over to the forward motor. Still had 1/2in of brush on the more used pair.
            6. Put covers back on then...
            7. Checked if the spindle tilts matched (using non-bent/repaired 70mm spindles), they differed by .3 to .5 deg. Adjusted one of them and now they are within .1 deg.
            The one issue that still stands out is that the right side motor does not free-spin nearly as easily as the left side motor (which usually acts as the rewind clutch). Having a motor instead of an adjustable clutch seems problematic relative the tension gradient across the wind. I did not go as far as removing the belts to try the two I have in the booth. I could test the drive shaft resistance by hand if and when I do remove belts. It's either there or in the bearings I expect. This matches with the "booth wisdom" to never use reverse (cause obvious cinch danger).

            Perhaps someone can confirm these are the correct belts?

            belt2.jpgbelt1.jpg

            Did some test winds. Using good house reels I was able to get a very respectable wind, almost as good as with the guide roller in use. If either reel is not so good the guide roller still gets us there. Seems improved, with room for more improvement with new spindles and maybe belts. Perhaps bearings. If we get fully tuned up then the Goldberg can go bye bye.

            wind-test.jpg

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            • #36
              Get rid of the dual-motor Kelmar table. It's a recipe for film damage. There is NO ADJUSTMENT AT ALL for winding tension. Even Kelmar admitted "it is what it is". With Kelmar still in business though, contact us (or another Kelmar dealer) and we can see what they would charge for just the left clutch side and then you could mount it on your table in place of the left motor.

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              • #37
                I fill in at a theater that used to thoroughly abuse their equipment, including shearing the keys off of the spindles because they regularly cranked the motor power to 100. A projectionist there got his machinist friend to rekey two of them for free, but they ended up not fitting all of the house reels. One didn't work very well at all and was relegated to the parts drawer. He put the other one into service, but he would be trying to file the key down on the fly when he needed to use a reel that didn't fit. Not good. I would bring old spindles of my own when I worked there until I finally got them to order new ones. They are a bit pricey though. I believe the last time I bought a set the standard 35mm spindle was $140. If you have a machinist who owes you a favor it wouldn't hurt to try to have them rekeyed, but it might be more trouble than it's worth. If you have to pay for it, you're probably better off just buying a brand new spindle.

                With regard to taking up on a split reel, you shouldn't do it. The clutch will be calibrated for house reels, so the tension will be too high if you're taking up on a split reel that has a lower mass and a small hub. Just rewind it twice. An E series Kinoton is designed to take be able to safely take up on cores as small as 2" but that's the exception.

                In terms of rewinding during the show, plenty of people do it but that doesn't mean it's the best practice. Since you already have two projectionists per show, take advantage of that and divide the work.

                The Goldberg WILL scratch prints. It should not be kept in service simply as a matter of convenience. It's great to have a second rewind station, but make a hand rewind station instead.

                The standard Kelmar table takes a 3L260 belt. I don't know if the dual-drive version is different but I would guess not. The size may be printed on the currently installed belts (although it may not still be legible). I second Brad's recommendation to dump the "reverse" head and replace it with a clutch. In the meantime... I sound like a broken record here, but hand rewinds are the easy way out.


                Originally posted by Ryan Gallagher View Post
                Is it worth having the spare 35mm kelmar spindles re-keyed? Or if they have obviously been bent and straightened in their past lives, just retire them and try to get new ones from kelmar?

                If we get the kelmar bench tuned up i'll take into advisement retiring the Goldberg auto. Though it certainly was handy on the occasional print we need to ship tails out. Two rewind stations utilized for each reel as they came off the projectors.

                That raises a question. If it's so important to monitor rewinds per this whole conversation, do most people save them until after the film? Or rewind as you go? Because we staff the booth with 2 for film screenings (one to juggle all the DCI/preroll/backup stuff)... we maintain the option to have monitored rewinds regardless of when we do it. Obviously this only applies to locales where shipping heads out is the norm.

                If you needed to ship tails out on cores, would you use a good condition split reel for takeup? Or stick to house reels and do the extra rewinding steps?

                Comment


                • #38
                  Extended-Key Kelmar spindles often need to be filed to work with typical Goldberg Cast Aluminum 20-minute reels. Their key is wider and taller than a standard spindle key. They were designed to work with the plastic shipping reels that used a sheet-metal key on each side of the reel. Those sheet metal keys would cut through the standard key. Still, if sized right, they will FAR outlast the standard spindle. Also, use dog-pin spindles if the reel has the appropriate hole in them. I've get to have one of them fail. Kelmar may still have the finger-hole drive spindles too though they were pricey and inherently not balanced. They don't have any key issues (don't have any keys) and won't work with split-reels or flanges.

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                  • #39
                    One problem with the extended key spindles is that some house reels don't have keyways that extend through the entire reel. Easy enough to check your reels for that if you're considering buying one, but it's an unpleasant surprise if you have a full reel that needs to be rewound ASAP and you find when you go to mount it that it won't fit on the spindle.
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                    • #40
                      So maybe our ideal is two new regular 35mm keyed, and if we are feeling spendy add one extended key specifically for plastic/plated rewinds. A finger hole one is appealing but i'd have to check that all our cast house reels support that. I know we don't have a majority that support the dog pin, just the split reels and non-cast ones but I'll look, cause yeah those are much nicer.

                      I'll consider owning my own spindles if I can't get them to bite... but I've already got a mountain of personal tools in our booth.

                      Retiring the goldberg auto rewind seems a winnable argument. But not sure about getting a clutch side for our kelmar table. Would it be crazy to jerry rig a clutched feed reel arm there instead if I can't convince them the kelmar clutch is worth it? We do have a spare set of 35mm reel arms. I consider our rewind improvements a higher priority than getting the 70mm mag head upgraded, cause rewind handling affects all film we touch. 70mm mag can wait, it's pretty rare for us.

                      Noted on the advice not to take up onto split reels. We haven't done it during my term, was just curious what is advisable.

                      I may temporarily install my personal HFC manual rewinds in place of the goldberg. That would at least leave us with two functional rewind stations. That table used to have some ancient vintage neumade rewinds... but they have been retired to the back room parts museum along alongside our RCA vintage tube amps (which I want to clean up some day).

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                      • #41
                        Originally posted by Jesse Crooks View Post
                        The standard Kelmar table takes a 3L260 belt. I don't know if the dual-drive version is different but I would guess not. The size may be printed on the currently installed belts (although it may not still be legible). I second Brad's recommendation to dump the "reverse" head and replace it with a clutch. In the meantime... I sound like a broken record here, but hand rewinds are the easy way out.
                        Cheers thanks for the belt sizing. yeah so the two I had were close but not quite. 27in vs 26in of the 3L260. With my luck they will be for the goldberg rewinds. lol

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                        • #42
                          It's not crazy, but I think the ultimate solution is to educate the folks who hold the purse strings about the importance of maintaining your projection equipment. They need to invest in the tools required to do the job. A working rewind table that won't damage film, reels that aren't badly bent or wobbly, and basic projector maintenance are the bare minimum, not some lavish expenditure. They need to budget for equipment maintenance, just like they budget for the cost of shipping prints.

                          Originally posted by Ryan Gallagher View Post
                          Would it be crazy to jerry rig a clutched feed reel arm there instead if I can't convince them the kelmar clutch is worth it? We do have a spare set of 35mm reel arms.

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                          • #43
                            Originally posted by Jesse Crooks View Post
                            What color stock has this been an issue with? I’ve used it on most common stocks (including plenty of IB Tech) and haven’t had a problem.


                            I used it on my collection, which included about every type of film you've ever seen, including IB Tech and Nitrate 35, and many 70mm. Never had any issues at all. In fact it seemed to keep the film from drying out and becoming brittle.

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