Jump to content


Photo

Eclair NPR Beauviala motor problem


  • Please log in to reply
3 replies to this topic

#1 bill santen

bill santen

    New

  • Basic Members
  • Pip
  • 2 posts
  • Student

Posted 29 June 2010 - 09:03 PM

Any suggestions are very much appreciated:
My eclair NPR crystal sync motor worked fine yesterday and this morning a disturbing pattern began. The problem occurs with or without the film magazine.
1. sync speed for 45 seconds, wobbling sound from the shutter, whine, motor disengages and runs at 1/8 speed-
2. after 45 seconds, restart camera and the motor is normal for 30 seconds
3. 15 seconds
4. 5 seconds

The square controller box becomes hot when the motor slows-

If the motor rests for an hour or more, the cycle can be repeated.

When the motor is removed from the camera body, the problem disappears.

Help!!
Thanks
Bill
  • 0

#2 Ian Cooper

Ian Cooper
  • Basic Members
  • PipPipPipPip
  • 469 posts
  • Other
  • England

Posted 30 June 2010 - 03:06 AM

Any suggestions are very much appreciated:
My eclair NPR crystal sync motor worked fine yesterday and this morning a disturbing pattern began. The problem occurs with or without the film magazine.
1. sync speed for 45 seconds, wobbling sound from the shutter, whine, motor disengages and runs at 1/8 speed-
2. after 45 seconds, restart camera and the motor is normal for 30 seconds
3. 15 seconds
4. 5 seconds

The square controller box becomes hot when the motor slows-

If the motor rests for an hour or more, the cycle can be repeated.

When the motor is removed from the camera body, the problem disappears.

Help!!
Thanks
Bill


Some of your symptoms sound similar to some problems I had with my NPR motor, assuming they are both the same.
I know it's not very clear on this snap, but this is the motor on my camera:
Posted Image

My problem was that everything would run fine, then for no apparent reason the motor would just stop. In this condition the switching FET bolted to the top of the box would heat up (thus warming the box). If the motor was removed from the camera then it was possible to see the motor shaft would turn slowly, but it didn't have any power behind it to drive anything.

With a bit of fiddling I seemed to track the problem down to the green connectors used to connect the motor and its feedback encoder to the control circuit board inside:

Posted Image

These appear to be unavailable these days, and there isn't much space in there to fit alternatives. I did solve that problem by carefully applying "silver conductive paint" to each of the contacts, then pushing the two halves together whilst the paint was still in its liquid state.

Once I'd sorted that problem, I then found it would run fine for 100's of ft of film before suddenly starting to play up and stall for no apparent reason. If the switch was turned off and the manual advance knob given a tweak then suddenly you'd see the motor wake up and return the shutter to the 'park' position again. I never did quite find a definate reason for that one, but think it might be related to load on the camera.

I found that the 'problem' seemed to be related to how well seated the motor was on the camera, and the exact angle of alignment between the two. By shuffling the motor position I was able to make it complain a lot more frequently, or almost not at all. Since sending the camera off for service/lubrication I don't appear to have had a repeat of the problem (touch wood).

I was put in touch with a chap here in the Uk that does camera electrical repairs, and is used to working on the NPR motors. He explained how circuit diagrams have never been available, and even supposedly motors of the same type have different value components - suggesting each one was tweaked on assembly. The green connectors going a bit dicky is a frequent problem, and if he can't fault find the circuits fairly quickly then it works out more effective to replace the circuit with a board of his own design.

If you're not 'into' electronic engineering, then there's nothing to see and nothing to adjust inside the box, but with a bit of care and a screwdriver it shouldn't be beyond someone being careful to open it up and wiggle the green connectors to see if they've got an intermittent connection, or dose them with conductive paint to see if it sorts things.

You mentioned that the motor runs fine when it's disconnected from the camera. Does it do the problem if you load the output wheel by rubbing it against something, or carefully squeezing with your fingers whilst not on the camera? If the camera hasn't been serviced in a long time then perhaps that's getting a bit stiff and needs a touch of oil? The fact that your times gradually reduce until you let it rest for an hour or so suggests something in the circuit is heating up (not just the switching transistor bolted to the motor box).

Sorry I can't really say what's wrong, hope you get to the bottom of the problem.
  • 0

#3 bill santen

bill santen

    New

  • Basic Members
  • Pip
  • 2 posts
  • Student

Posted 30 June 2010 - 07:25 AM

Some of your symptoms sound similar to some problems I had with my NPR motor, assuming they are both the same.
I know it's not very clear on this snap, but this is the motor on my camera:
Posted Image

My problem was that everything would run fine, then for no apparent reason the motor would just stop. In this condition the switching FET bolted to the top of the box would heat up (thus warming the box). If the motor was removed from the camera then it was possible to see the motor shaft would turn slowly, but it didn't have any power behind it to drive anything.

With a bit of fiddling I seemed to track the problem down to the green connectors used to connect the motor and its feedback encoder to the control circuit board inside:

Posted Image

These appear to be unavailable these days, and there isn't much space in there to fit alternatives. I did solve that problem by carefully applying "silver conductive paint" to each of the contacts, then pushing the two halves together whilst the paint was still in its liquid state.

Once I'd sorted that problem, I then found it would run fine for 100's of ft of film before suddenly starting to play up and stall for no apparent reason. If the switch was turned off and the manual advance knob given a tweak then suddenly you'd see the motor wake up and return the shutter to the 'park' position again. I never did quite find a definate reason for that one, but think it might be related to load on the camera.

I found that the 'problem' seemed to be related to how well seated the motor was on the camera, and the exact angle of alignment between the two. By shuffling the motor position I was able to make it complain a lot more frequently, or almost not at all. Since sending the camera off for service/lubrication I don't appear to have had a repeat of the problem (touch wood).

I was put in touch with a chap here in the Uk that does camera electrical repairs, and is used to working on the NPR motors. He explained how circuit diagrams have never been available, and even supposedly motors of the same type have different value components - suggesting each one was tweaked on assembly. The green connectors going a bit dicky is a frequent problem, and if he can't fault find the circuits fairly quickly then it works out more effective to replace the circuit with a board of his own design.

If you're not 'into' electronic engineering, then there's nothing to see and nothing to adjust inside the box, but with a bit of care and a screwdriver it shouldn't be beyond someone being careful to open it up and wiggle the green connectors to see if they've got an intermittent connection, or dose them with conductive paint to see if it sorts things.

You mentioned that the motor runs fine when it's disconnected from the camera. Does it do the problem if you load the output wheel by rubbing it against something, or carefully squeezing with your fingers whilst not on the camera? If the camera hasn't been serviced in a long time then perhaps that's getting a bit stiff and needs a touch of oil? The fact that your times gradually reduce until you let it rest for an hour or so suggests something in the circuit is heating up (not just the switching transistor bolted to the motor box).

Sorry I can't really say what's wrong, hope you get to the bottom of the problem.


  • 0

#4 Boris Belay

Boris Belay
  • Basic Members
  • PipPipPip
  • 210 posts
  • Other
  • Brussels, Belgium

Posted 08 July 2010 - 04:49 PM

Any suggestions are very much appreciated:
My eclair NPR crystal sync motor worked fine yesterday and this morning a disturbing pattern began. The problem occurs with or without the film magazine.
1. sync speed for 45 seconds, wobbling sound from the shutter, whine, motor disengages and runs at 1/8 speed-
2. after 45 seconds, restart camera and the motor is normal for 30 seconds
3. 15 seconds
4. 5 seconds

The square controller box becomes hot when the motor slows-

If the motor rests for an hour or more, the cycle can be repeated.

When the motor is removed from the camera body, the problem disappears.

Help!!
Thanks
Bill


Hi Bill,

I agree: if the motor has torque when off the camera, then the problem could come from the camera (the motor overheats and slows down because of too much mechanical drag). To test this, try 1) to hold the motor shaft with varying pressure from your fingers (perhaps with gloves on) while off the camera and see how much torque it seems to have. 2) Turn the camera mechanism from the rubber coupling to the motor (motor still off, obviously) and see if it seems unusually hard. It should be fairly easy to turn the mechanism, and above all, there should be no hard spots when you turn it. If you feel a hard spot, see whether it happens always at the same point in the cycle, and try to identify which mechanical part may be the problem. Basically, the shutter revolves continuously, while the claw has an intermitent pattern.

If the mechanics of the camera seem fine, turning easily and smoothly, than the problem is indeed probably with your motor. The electronics on these Eclair Beauviala motors is antique (by electronics standards) and difficult to repair. I would try Electro Optical House for that, as George seems to be one of the few that knows and still bothers to dig into these old beasts. Otherwise, eBay regularly has (very cheap) NPR motors... and as you found out, a spare is always good to have anyways!

Cheers,
Boris
  • 0


FJS International, LLC

Aerial Filmworks

CineTape

Glidecam

Technodolly

Wooden Camera

CineLab

Metropolis Post

Gamma Ray Digital Inc

The Slider

Tai Audio

Willys Widgets

Opal

Paralinx LLC

Media Blackout - Custom Cables and AKS

rebotnix Technologies

Abel Cine

Ritter Battery

Visual Products

Rig Wheels Passport

Broadcast Solutions Inc

Ritter Battery

Glidecam

The Slider

Media Blackout - Custom Cables and AKS

rebotnix Technologies

Metropolis Post

Willys Widgets

Aerial Filmworks

Tai Audio

CineLab

Opal

Abel Cine

Broadcast Solutions Inc

Technodolly

FJS International, LLC

Wooden Camera

Visual Products

Gamma Ray Digital Inc

Paralinx LLC

CineTape

Rig Wheels Passport