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Posted

Hey All,

I'm moving this thread here as I figured a discussion here may be helpful to others.

I recently acquired an 16BL for next to nothing and was already cautious about purchasing an item that had no history of whether or not it worked.

I first attempted to power the camera at the rental house, and it appeared to only want to "take off" on me and run at a very high fps, essentially maxing out. I didn't want to damage the motor so I would only run the camera in short bursts. 

The camera came with a crystal motor (Georg Jensen 505) and figured it may be that -- It wasn't. Even bypassing the crystal motor the camera did the same thing..

I called Andre at AMCamera here in Los Angeles and described my problem. He said that when the camera wants to "take off on you" that it is likely to do with a failure to send a Signal Pulse. My knowledge is very limited here so I could really only understand this as to be 'no good'. Perhaps one of you can better describe this phenomenon. 

I ended up taking the camera over to Tyler Purcell who was an immense help at showing me where the problem might lie. He tested various systems and came to a conclusion that the problem likely lies on the motor tach board itself.

So while I wait for Du-All and Visual Products to get back to me, I'm hoping that I might find a wiring circuit diagram of the motor (if anyone has one) ad attempting to find out where the problem of the components lies. 

 

Hope to take yall on this journey of repairing this old camera and bringing it back to life in the new millennium lol 

- T

Posted

After a bit of research, it seems this is an ARRI motor and is called a BLE motor. Apparently one of the 3 options ARRI supplied for the 16BL. Now my next question might be, does this motor NEED a crystal sync unit to be attached in order for it to be 'governed'?

Posted

Nope, it has a rudimentary motor controller built in, i can post schematics of the motor electronics later when i'm at home

its controlled with a small governor that keeps the speed roughly +-1fps. you need a plug/cable with the right pinout to make it work correctly though. Basically the camera has a small tachometer that produces an ac signal, that signal is routed to the rear 12pin plug, then by the correct arri cable back into the built in, rudimentary motor controller, idea being that a quartz controller can just take in the tachometer input and then inject its own PWM signal to the motor transistor.

 

Posted
6 hours ago, Vincent Wolfram said:

Nope, it has a rudimentary motor controller built in, i can post schematics of the motor electronics later when i'm at home

its controlled with a small governor that keeps the speed roughly +-1fps. you need a plug/cable with the right pinout to make it work correctly though. Basically the camera has a small tachometer that produces an ac signal, that signal is routed to the rear 12pin plug, then by the correct arri cable back into the built in, rudimentary motor controller, idea being that a quartz controller can just take in the tachometer input and then inject its own PWM signal to the motor transistor.

 

Hey Vincent, thank you for your reply

A wiring diagram would very helpful to me and I imagine that they are very difficult to come by.

In all honestly, I will need to get up to speed regarding this technical information as I don't have a background in electronics -- but i'm willing to give it effort to learning so.

Posted

UPDATE:

I spoke with Andrew at AZ Spectrum in NYC. I believe he works primarily on older film cameras.. Anyway, he says that a common problem with these cameras is that within the motor, there is a magnetic disc (which I believe acts like a Hall Sensor) that sends a signal pulse by "disrupting" via it's magnetic field each time the motor spins a rotation. 

In the motor if you see the photos, it's that silver object positioned at about 7 o'clock. 

He said that over time the magnetic field becomes weak and no longer is able to create a pulse, so he suggested I either introduce a new magnet by replacing or just physically sticking on on there in order to mimic this effect. 

I will try this either today or tomorrow when i'm in a position to plug this into a battery as I don't own one.

Posted

Havent had time to scan those old circuit diagrams yesterday, i'm sorry.

I cant seem to open your images, i think you need to set your google drive links in a way that everyone can see them.

Posted
3 hours ago, Vincent Wolfram said:

Havent had time to scan those old circuit diagrams yesterday, i'm sorry.

I cant seem to open your images, i think you need to set your google drive links in a way that everyone can see them.

My apologies! Let me know if that has fixed it.

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