Moviecam SuperAmerica 3 perf movement conversion question
Posted 11 November 2015 - 10:15 PM
Basically, what I'm wondering is if anyone has a 3 perf conversion kit. I know they made them and I know some of the arri parts fit this camera, including some movements. Since I'm a noob to the whole situation, figured I'd make a post and see what is available. I can't afford to shoot 4 perf, especially since 90% of my work will be finished digitally.
Posted 12 November 2015 - 09:02 AM
Are you sure they made a 3-perf conversion kit for the SuperAmerica?
I'm really only familiar with later Moviecams, but I always thought they only made 3-perf movements for the Compact MkII. Could be totally wrong though!
It's a pity Moviecam have completely shut shop, for a number of years after Arri bought them you could still get good technical support, even less than 10 years ago. But now not even Arri has any information as far as I'm aware. Maybe some rental houses could help you out, if you called around.
Posted 12 November 2015 - 03:22 PM
Arri has given up all support for older film products. I was just hoping someone may have some parts lying around ya know?
Ohh yea, I've been to rental houses. Nobody has anything for those cameras in L.A. anymore. They have some SL parts, but no movements.
Posted 12 November 2015 - 05:17 PM
Are you sure those weren't just matted gates?
Maybe they are... but why would they make a 2 perf matted gate? Seems strange to leave so much negative unexposed.
Posted 22 November 2015 - 07:01 PM
It uses an offset cam design, where a shaft fits through two rotating cam's. Those cam's profile decide how much the pull down mechanism moves. I tried to get the assembly apart, so I could measure the cam's profile and maybe do some math, however even after taking out all the screws that hold it in place, it wouldn't budge. Since it's a working camera, I didn't want to put too much force on it, so I gave up and put it back together again after around 4hrs of studying and analysis.
Good news is, I found someone online who did it with their superamerica, so it's possible. I e-mailed them and hopefully they'll get back to me. In any event, it was fun exploring and the more hands-on I get with this camera, the more knowledge I gain.
Posted 23 November 2015 - 06:20 AM
it's your camera so you can do what you like with it, but as someone who has worked on this kind of gear I thought I should mention a few things.
A modern sync sound camera like yours is a very finely tuned machine. It's not like a lawnmower that you can pull apart and examine how it works and put it back together and expect it to work perfectly again. In the movement/gate area there are probably dozens of adjustment settings, each set to tolerances of around one or two hundredths of a mm and often requiring special gauges, jigs and optical test tools. It's very important to know which screws you can undo and which you should leave alone. Anything that is sealed or painted in should definitely be left untouched, but even undoing unsealed screws can sometimes lose an adjustment.
Now some settings are more crucial than others, maybe they only affect lens mount to gate centring and things like zoom tracking, or maybe it's a belt tension adjustment to keep the noise level down, or maybe it's a levelling adjustment that prevents one corner of the groundglass image from being a bit soft, etc.
But maybe a setting controls the film channel width (or more likely one side at a certain height) and the film is now being bruised as it passes through and much more likely to jam. Or it might be one of many adjustments that can affect the flange depth, which will cause soft images, maybe only on one side. Or it could be something that affects steadiness, or simply heats up a moving linkage until the camera just seizes up.
Pulling down an Arricam/Moviecam movement is something I very rarely attempted, and only to a certain level, otherwise the settings get lost and it needs to go back to the (now non-existent) factory. There are multiple linkages in there, all finely shimmed or calibrated, and it all needs to move freely without any tight spots or play. The pulldown is not just a question of distance, but also curvature and dwell.
If you're serious about trying to manufacture your own 3 perf movement I would suggest getting the help of technicians who are familiar with the camera. You will need a new gate, which is extremely crucial and not at all something easy to fabricate either, and it needs to be positioned correctly. You could try contacting Aranda Film who used to specialise in conversions, but I don't know if Bruce is still working, and I'm not sure he ever converted Arricam/Moviecams.
Personally I think you should keep it 4 perf unless you find a conversion kit that would work with your camera, and even then it will be at least a day's work for a technician to fit and adjust it. That's how long it used to take me to fit a new 3 perf movement to Arricams and Moviecam Compacts, using factory jigs, measuring gauges, shaped shims, new belts and gears. The electronic timing needs to be reset, the mag electronics upgraded. It's not a hobbyists job, and will be expensive.
But again, it's your camera and you can do what you want with it. I don't want to come across like some finger-wagging know-it-all. I was working on rental house cameras used for features and stuff where they had to be reliable, quiet and produce the sharpest, steadiest images they were capable of making. Not everyone needs that level of exactitude I guess.
Anyway, just some information to think about. Good luck with your project.
Posted 23 November 2015 - 01:29 PM
I'm actually a pretty good technician, I've worked on far more complex things in my life. I wanted to pull it apart to figure out if it was something that I and another machinist could do, but alas, I feel its a bit more then simply mechanical changes. It was great to understand how it works, lubricate everything and throw it back together again. That was a real treat and worth the effort.
I'll contact those guys in Australia see what the deal is.