NPR Perfectone Motor Problem
Posted 15 July 2011 - 11:40 AM
Posted 15 July 2011 - 02:00 PM
Posted 15 July 2011 - 02:25 PM
Posted 15 July 2011 - 02:38 PM
Maybe lubrication of the motor/shaft, etc?
With the power disconnected, turn the shaft by hand. If it feels OK, I wouldn't mess with it. If it feels gummy or grindy, that's the problem.
Posted 15 July 2011 - 05:33 PM
Posted 16 July 2011 - 07:17 PM
Posted 17 July 2011 - 03:41 AM
Disassembled the power connector and switch - meter reading was a full12v at the connector and the switch simultaneously. I removed both end caps, applied power, and just wiggled the motor around inside the casing... It fired right up. I'm not sure what I did to make it work... But at least it's worth something other than a paperweight for the moment.
Sounds like good news. Does your motor use the unreliable 'green' connectors, like the ones shown in this thread I started on my motor? In the end I replaced them with a modern alternative (which was a bit of squeeze to get inside the box!). Although I haven't used the camera a great deal since, I haven't experienced the motor problems when I have. If all you've done is wiggle connectors around then it sounds like a similar issue.
The fact the 'sync' light came on whilst the motor wasn't turning isn't too suprising. Whilst I don't know the precise details of your motor, in general closed-loop speed control means the motor will be driven by a PWM (pulse width modulated) voltage. The width of the pulses will determine the motor speed. There will be a speed feedback sensor fastened to the motor which will give an indication of the motor actual speed. The control circuit will compare the speed feedback from the motor to the reference speed generated by a crystal oscillator (or from a user twiddly knob), then adjust the width of the pulses driving the motor until the error difference is reduced to zero. If there is a big difference in speed references then it will apply a large correction to the motor pulses, if there's only a small difference in speed then it will only tweak the motor drive pulses slightly. If the difference is too great then the 'sync' light will be illuminated.
The fact that the motor wasn't turning would mean no speed feedback, so the error difference between actual speed and the crystal reference would be large, so the sync light would be lit up. This would suggest the problem lay on the drive side to the motor - either the connection to the motor, the transistors used to drive the motor, or the circuit generating the pulse train.
If you loose the feedback from the motor then once again the difference signal will be large and the circuit will try to compensate, only what will happen is the motor will run up to maximum speed in a vain attempt to reduce the speed error (or it will stop if it thinks the motor is running too fast, which is an unlikely failure mode). In this case the suspect areas would be the speed sensor on the motor, its connections back to the control circuit, then any electronics which process that signal and compare it to the crystal reference.
If you haven't got the equipment (oscilloscope) to start tracing the signals through the circuit then you'll struggle to do much more than plug wiggle or look out for obviously damaged components. Even with the relevant test gear one will still struggle without a circuit diagram to show exactly how the components are connected. Eclair didn't make life any easier by wiring everything together with great bundles of wires all the same colour!
Posted 19 July 2011 - 05:08 PM
No "green" connectors in my motor. Once the controller box is removed from the top of the motor, it's pretty much just a circuit board. I definitely notice that the more I play with the motor...turning it on and letting it run for a bit, increases the response time. If I let it sit overnight and hit the power, it's response isn't as fast to get up to sync speed a if it's warmed up. Again, not sure why.
Anyway, taking it apart and wiggling things around seemed to get it going! I'd love to have a Tobin motor - they seem hard to come by though
Posted 20 July 2011 - 02:03 AM
...I definitely notice that the more I play with the motor...turning it on and letting it run for a bit, increases the response time. If I let it sit overnight and hit the power, it's response isn't as fast to get up to sync speed a if it's warmed up. Again, not sure why...
Is that with it connected to the camera, or seperate?
If it's connected to the camera it might suggest it could benefit from a clean and re-lubricate? After you've let it run for a bit the greases and oils will have had chance to soften etc, motor warm though (ie. make the lubricant in its bearings soften up as well), so the camera load will be reduced a bit compared to when you start it 'cold'?
I don't know what your motor is like 'normally', my own motor reaches sync pretty much instantly. If 'wiggling' gets yours going then it suggests connector issues, or possibly dry solder joints? Both could give increased impedance on the motor connections and thus perhaps less starting current available to the motor, and therefore reduced starting performance??
Afraid that's somewhat clutching at straws and guessing though.
Posted 25 July 2011 - 04:44 PM
Posted 25 July 2011 - 06:03 PM
and the fact that your motor fired up when wiggled
suggests a connection problem rather than bad electronics.
I would look for something loose, broken, brittle, cracked, etc.
in the power wiring to the motor, maybe even inside the motor
Posted 26 July 2011 - 05:08 PM
...it definitely reaches sync speed in half the time... a second or two versus five to ten seconds.
Once again, I don't have any personal experience of the Perfectone Motor - I don't know exactly what the motor model on mine is - but five to ten seconds doesn't sound 'normal'. My motor hits sync in less than a second, it's as good as instant.
Afraid I can't think of much else to suggest you could easily try yourself.
Sorry, but best of luck trying to track down the solution.
Posted 26 July 2011 - 07:02 PM