Jump to content

Arriflex 16 S


micheallLeake
 Share

Recommended Posts

  • 3 weeks later...

Your motor is the basic Arri 16 S / 16 M Governor Controlled motor that was modified to output a 1 volt sync pulse/signal that was fed to a 1/4 inch synchronous tape recorder. One would plug the sync cable (umbilical cord, as it was called) from the recorder into the single pin RCA jack located on the back of the motor next to the knurled turning knob. Any minor speed variations or fluctuations of the camera would be recorded on the ¼ inch tape.

With this motor you could then shoot lip-sync sound with your noisy Arri 16 S (with additional sound coming from the 400 ft torque motor) or M camera (well, maybe the camera was in that user friendly ‘blimp’). You wouldn’t need an A.C. power supply or the Arri a.c. sync motor for sync filming. The camera was driven by batteries and same for the recorder. 

“Governor controlled motor for 8 V battery operation with fixed camera speed of 24 (Cat. No. 1161) or 25 frames per second (Cat. No. 1162). This speed is automatically maintained and cannot be changed. The speed required should be stated when placing an order. Other speeds can be adjusted on request. This motor is designed for forward drive only, and a knurled knob for turning the camera mechanism by hand is also provided.”

Most likely the speed of your motor is 24 fps. You can always check the speed of the motor on the camera with a strobe light.

The motor used for this modification was the early Arri Governor Controlled motor. This was the one without the transistor attached to it. I would guess your motor is from the early to late 1960s.

The sync pulse modification did not change the operation of the motor. 

So, now you have a constant speed motor (24 fps) for your 16 S camera.

This motor was modified by Magnetic Sales Corp, an equipment division of Loren Ryder’s ‘Ryder Sound Services, Inc’ at the same address.

Loren Ryder started his business in 1948. He was an early pioneer in magnetic sound recording for Motion Pictures, initially working for Paramount. He became a leader in the industry for portable magnetic recording on location.  https://en.wikipedia.org/wiki/Loren_L._Ryder   There is a nice article about him in the May 1973 American Cinematographer.

 

 

Link to comment
Share on other sites

  • 1 year later...

Does anyone here know how much power a fixed speed arri 16s motor draws.  I'm looking at using a RC model power supply that is 45WH,  5000 mah, 8.4 volts.  Seems like it would be more than adequate, but not sure how much juice the motor pulls and how long I can expect the camera to run on a full charge.

Link to comment
Share on other sites

  • Premium Member

Steven;

I feel sure this may not answer your question, however;

Some time ago I constructed a battery pack with two 15.3 V lithium polymer batteries. I have a buck convertor with which I can regulate voltage and amps from 3.7V to 15.3V. I can get exactly the voltage I need, and I can switch between batteries without interruption of power.  I have no idea how long the power will last because I have never run my arri 16 more than 30 minutes. I can also use two different poser cords, one an arri original power cord and one which is custom built.

E22F1FF5-01CF-4A8F-AF09-8BA6876DE9BA.jpeg

7E22FC0D-431A-4F1D-B0FE-901A836C265E.jpeg

DB1D3D3D-511C-4581-803A-6F1E4FFC055E.jpeg

Link to comment
Share on other sites

That looks pretty cool.  I'm hoping for a much simpler solution.   I did actually get the RC battery and I'm trying to decide if I landed on a defective battery pack (it is certainly a cheap one).  At 8.4v and 5000mah or 5 amps, I reckoned on this powering the arriflex for at least 20 minutes continuously without a problem, but it can only manage about 20 ft of film before slowing down and then coming to a complete stop.  

Link to comment
Share on other sites

On 6/11/2020 at 5:00 AM, steven jackson said:

At 8.4v and 5000mah or 5 amps, I reckoned on this powering the arriflex for at least 20 minutes continuously without a problem, but it can only manage about 20 ft of film before slowing down and then coming to a complete stop.  

You should get at least an hour with that sort of capacity. 

Do you know if the motor works properly?  Does the camera turn over manually without much effort? Does it run without film? Could there be resistance in the power cable or plug, how did you wire it up?

Link to comment
Share on other sites

Thanks Dom, I have run film through the camera and it functions well and turns easily, as does the motor.  I've decided that my cheap battery problem is exactly that...it's a cheap battery that doesn't live up to it's claims on power (the cells are C size, which seem a bit small to be able to offer of 5000mah).  I also question the charger I bought as well.  I've decided to re-purpose an Eclair battery back and rebuild it with better quality NiMH batteries. I have included a photo of the battery in question. 

Screen Shot 2020-06-12 at 07.34.13.png

Link to comment
Share on other sites

  • 6 months later...
  • Premium Member

I used those RC car batteries to power the 24fps constant speed Arri motor for years. Checking with a strobe, the speed was spot on. I think the RC car batteries were 7.2 volt or 7.4 volt, can't quite remember. Turned out to be a much cheaper way to shoot with those cameras compared to the battery belts.

Best, -Tim

Link to comment
Share on other sites

I use similar style RC batteries too to power Konvas cameras. They work very well in that application but the cheapest ones have crazy self discharge rates which is why I need to charge them at least couple of days before shooting with the camera or they don't have any charge left for filming.

The cells which have higher mAh rating compared to size tend to self discharge faster by my experience and the "overrated" mAh capacity may indicate that the battery is a bit lower quality than the counterparts which use physically similar sized cells with less rated capacity.

You did fully charge the batteries before testing them with the camera or were they left charged for longer period and then you tested the camera assuming that the batteries still had the full charge in them? in case of those rc batteries they may have something like half of the charge left if you store them couple of weeks or a month. Can be even almost empty if storing for couple of months and they are bad quality ones

Link to comment
Share on other sites

I had no luck with these RC batteries but they were the mega cheap ones so perhaps that was the problem.  In the end, I built my own battery pack using Amazon batteries, D cells rated at 10,000mah and they have proven to be excellent.  I re-used an old Eclair battery pack and soldered up 7 1.2v D cells and it works a treat.  I still haven't had to charge it after using it numerous times.  All in for under $50.

Link to comment
Share on other sites

  • Premium Member

C20D6538-A248-4A92-8E71-3BAF10BC57FE.thumb.jpeg.1101c70f42147dfb00670c19c4605519.jpeg1CD35AA0-CA02-4281-90E2-BCD61B0C1250.thumb.jpeg.e46ba5a7c09add37c91a64d638690371.jpeg0782FB42-0A2B-459B-BE28-C3769CB520DD.thumb.jpeg.2fb057ec159694b7fe2b7e3bc82b03c2.jpegF3D934A8-B95D-4349-B157-CFB176F9B250.thumb.jpeg.1fd1bda8463eaf0910d95dc0dd16d7ad.jpeg

Starting with the bottom photo, I have 2 turnigy 4 cell 5000 mAh Lithium batteries.

I have not charged or used them in one year and they are still holding a 15.4 volt charge. The middle photo shows 2 power outputs. One for my standard vintage Arri power cable to my arri 16s and the other is an output is from an r/c drone supply company. This outlput powers my Beaulieu R16.  The center led shows the power of each battery(I can switch from one battery to the other without interruption of power) The center led(which is on a buck converter) also can be switched to display the power going to the camera. the power going to the camera can also be adjusted. the 2 top photos are details of the power output plugs. If anyone needs anymore information, let me know.  I could only post this many photos because of 9.77 MB limit

Thanks

Michael Leake

Link to comment
Share on other sites

  • 4 weeks later...
  • Premium Member

I'll jump in this topic because it seems related...

I just got a constant speed 24fps motor for my 16S off of ebay (picture below). It's the kind with the transistor on the side. When I run the camera with it the tach reads 23fps.  Using an iPhone app called "Video Tachometer" it seems to be running at 22.83fps.  No wandering, it's very consistent.

How can I tell if this is an 8V motor (if it's a 12V motor could that be the problem?)   Or were the simpler Arri motors always 8V?  I'm using 7 NiMh "F" cells in a pack I built, so that's nominally 8.4V.  If it's the right motor, how do I tweak the speed - assuming the tweak range even goes that far?

AM I correct in thinking that even if the camera were a little old and sticky in the lube department, a constant speed motor would just work harder but still keep a constant speed?  The fact that the motor and mechanism don't sound like they are struggling at all, and that the speed is dead-constant makes me think that it's just the motor inherently adjusted too slow.

(Tangentially-related question: why is there a matte black stripe dead center on each of the two mirror portions of the shutter?  It certainly makes seeing what's going on with the app easier!  So maybe that's why it's there...)

Thanks,

Duncan

arri6s_motor_01.jpg

Link to comment
Share on other sites

Could it be that either your motor bearings are tiny bit sticky or that the brushes or commutator need cleaning.  You are meant to lubricate the camera at the two ball bearing points in the film compartment if the camera has been sitting a while and it's apparently bad to run it without doing this first.

Link to comment
Share on other sites

  • Premium Member
2 minutes ago, steven jackson said:

Could it be that either your motor bearings are tiny bit sticky or that the brushes or commutator need cleaning.  You are meant to lubricate the camera at the two ball bearing points in the film compartment if the camera has been sitting a while and it's apparently bad to run it without doing this first.

I'll accept about anything as a possibility!  I'm new to Arri cameras, though I have a lot of experience with cameras and electromechanical things.  There are no indications that the camera is in desperate need of lube (though as some point I will lube it or have it lubed professionally).  And I don't know how the speed governor works in these motors but I would think up to a point the governor would hide a lot of ills like bad bearings or brushes by just working harder/hotter to maintain its set speed.

Duncan

Link to comment
Share on other sites

I have had the experience of my 16st running slightly slow because of a bad contact between the rubber cable plug end and the camera plug socket pins. There was nothing visibly wrong that I could see but using a different cable sorted it out.  In theory, this bad contact idea could also apply to the switching mechanism (metal contact points) located in the film compartment.

Link to comment
Share on other sites

  • Premium Member
16 minutes ago, steven jackson said:

It could also simply be the rubber drive coupler is worn or stretched and isn't gripping the motor shaft as it should.

 

It's a brand new one from Sean Charlesworth.  Which to be fair, may not act identically to a real Arri one would (if you could still get them), but I'm pretty confident he knows what he's doing.  So I'm not ruling that out, but again the absolutely unwavering speed at which it runs makes me less suspicious of things like that, which would likely present as a more erratic result.

Duncan

Link to comment
Share on other sites

  • Premium Member

To all; I have purchase several arri 16 motors from eBay, they all had issues. I finally made

a crude device to measure torque of the motor clamped gently in a vise.  They all were different. The ones with the most torque resistance I disassembled and replaced the bearings and the brushes. Unsealed bearings (in the motor)  were replace with sealed bearings(purchased from the internet). The rebuilt motors worked much better.  I also had disassembled the arri 16(very carefully, and with lots of reference photos), lubed and reassembled. On my mirror, I removed the black bowtie paint(very carefully as the mirror is front or top silvered, and you do not want to scratch it). 

ML

Link to comment
Share on other sites

  • Premium Member
7 minutes ago, Michael Leake said:

The ones with the most torque resistance I disassembled and replaced the bearings and the brushes.

Anything tricky about disassembling the motor, or pretty straightforward and is obvious as you get it apart?  I'm a whiz at reaplacing bearings in random things, but have never tried to find replacement brushes for a small motor before.  Do you have a source?

 

9 minutes ago, Michael Leake said:

On my mirror, I removed the black bowtie paint(very carefully as the mirror is front or top silvered, and you do not want to scratch it). 

Any insight as to why that's even there?  It does seem like it would make the viewfinder image that much less bright when filming.

Duncan

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...