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Is there a demand for custom sync sound motors?


aapo lettinen
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I would assume that "bridging it" is a more precise term. I forgot to unplug the motor and whilst I tried using a multimeter to see if it was working. I knew power was coming in but not reaching the brushes and was trying to wok my way back.

I couldn't fin a schematic on the internet so I looked at the closest model to it which would have been a Perfectone NPR Motor. I gave it some thought and wondered if the circuit was a similar design. The switching seems the same and it contains so identical parts like the OC 30 transistor so I guessed that they may be similar. There's a 0.66uF capacitor in this diagram and maybe the 0.22uF one in my motor had a similar function? That's about the limit to my understanding of circuits:

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Wow, OC30 is one old germanium transistor! 

I am still not sure what you meant with "bridging". What Mode was your Multimeter set to when you measured, I guess on the two legs of that capacitor?

I wouldn't be too sure that schematic you found is the same in your camera, but it is neither impossible. 
- If your cap is dead, like shortened, measuring over it in any mode should not make a difference.
- If your cap is not dead, but lacks capacity (dried out), and your multimeter was in continuity mode, your brief "bridging" might have "simulated" what the cap was intended to do: Create a pulse (to get the motor going). 

Can you reproduce to start the dead motor with your "bridging" trick? And again, what is your multimeter set to?

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I set the multimeter to 2K resistance. Same thing happened today, plugged it in, switched it on, nothing happened. When I connected the multimeter to the two ends of the capacitor the motor started running. I didn't let it run for more than a second as I was using a V-lock battery that's rated just under 14vdc and the motor is rated 12vdc. The only thing I know about this motor is that they were for sale in the Cameflex Brochure back in 1971. So I reckon it's 50 years old. There's also a Motorola Transistor 2N 1557 5.36 but I can't see one in the diagram. I also got three old Camematic motors up and running using 3 PP3 Batteries in series to make 27v.  They all seem to run fine as they don't have any of the circuitry of the Perfectone.

 

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Huh, I feat I can't help you further w/o the actual schematics (if at all). I'd swap the cap as an almost free try (well, few cents, if you have none around) — that's low risk. 

BTW, when you have your Multimeter in Resistance mode, your are not "bridging" the cap. In the multimeter is a battery and you are sending a current through the test leads. That current might well also go thorugh the transistors (and whatever is connected with that cap) and hence "make it appear alive" — so I wouldn't bet too much that the cap is to blame.

Germanium transistors do not like vibration/concussions. Might well be that one of them died. They are around 60 years old after all...

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I am not able to help with that Eclair motor, never had that type of motor so I don't know about its electronics. One could work out the schematics by taking off the boards and carefully documenting all the connections but probably it would be easiest to just get a Eclair specialized repair tech look at it (if there is still any around) or replace the electronics with completely new ones. 

So there is a pilot tone generator available which works? if so, one could use it as a "encoder" to get speed measurement for a new self made speed stabilizing system. one needs to work out a good preamplifier for that (oscilloscope and multimeter needed) to condition the pilot tone signal to the form which can be accurately and safely read by the microcontroller

Edited by aapo lettinen
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  • 2 weeks later...

Here's something crazy. I've been wracking my brains trying to solve the problem with the Perfectone motor. It turned out not to be transistors, capacitors or diodes. It was a piece of dirt underneath one of the contacts on the synch pulse generator. Just got it up and running Adam very happy. Apart from buying a bunch of components that I don't need now.

So, now I've got the motor running I'd be interested to hear your thoughts about using the synch signal to provide reference to a speed controller. I found some photos a while back that showed a Perfectone motor controller that I assume was their version of a crystal lock mechanism. My friend in Switzerland managed to track down someone from Perfectone. Once I've had a word with him I'll let you know what their solution was.

Cheers

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44 minutes ago, Marek Budzynski said:

Here's something crazy. I've been wracking my brains trying to solve the problem with the Perfectone motor. It turned out not to be transistors, capacitors or diodes. It was a piece of dirt underneath one of the contacts on the synch pulse generator. Just got it up and running Adam very happy. Apart from buying a bunch of components that I don't need now.

So, now I've got the motor running I'd be interested to hear your thoughts about using the synch signal to provide reference to a speed controller. I found some photos a while back that showed a Perfectone motor controller that I assume was their version of a crystal lock mechanism. My friend in Switzerland managed to track down someone from Perfectone. Once I've had a word with him I'll let you know what their solution was.

Cheers

glad that you got it working so easily!  

most of the motors which already have a pilot tone generator or a encoder of some kind installed are pretty easy to adapt to use your existing speed control systems. The tough part is to actually design and manufacture the speed control. You need to make custom circuit boards by yourself and so on. It becomes very tricky and time consuming very fast. 

So you want to get a usable square wave signal from the pilot tone generator and to have a way to use a microcontroller system like Arduino to control your brushed motor power. 

If it is a true generator it probably outputs some kind of sine wave. You do have a oscilloscope I assume? if not, now is the time to purchase one. Because you need to confirm what type of wave the pilot tone generator outputs and how many cycles you get from there per motor revolution. I use laser tachometer and oscilloscope to measure this data.  First it is useful to run the motor normally and measure the voltage of the pilot tone generator output with a multimeter to ensure the voltage range is correct for your oscilloscope. After confirming the pulses per revolution count, the waveform and the voltage range you need to design your own preamplifier which converts the sine wave or "almost sine wave" to a square wave with proper voltage  and proper duty cycle so that your sync system can use it. Ideally you would convert it to 5V peak square wave with 50% duty cycle and feed that to the microcontroller which does the speed measurement stuff. 

Then you do you programming magic to measure the needed info from the signal. And you will generate a correction signal which is fed to the circuit which adjusts the motor power. 

You can for example take the pwm correction signal you generated in the software and feed it either directly to a mosfet which controls the motor power, or if the voltage difference is too high for saturating the fet you can first preamplify the pwm signal to the same voltage level than the motor uses (for example you amplify the 5V pwm signal to 12V level and then feed that to the mosfet which actually controls motor power) . IF you need to amplify the signal first with a bipolar transistor before feeding it to the FET you need to ensure with oscilloscope that the transistor circuit does not distort the waveform too much. 

Typically it takes about 30min or one hour to get it working correctly if your software is already fully ready and tested with another system. Have you already made your simple brushed motor control code like I suggested earlier?  the speed measuring one which is simple and fast to write? 

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On 2/13/2020 at 1:56 PM, aapo lettinen said:

I became interested in microcontrollers a while ago and I am considering a DIY sync sound motor for my Kinor 2m camera. I also have other cameras which could use a stable speed motor (for example my 35mm Soyuz-US3N camera and the rheostat motored Konvas 1KCP. This is because there is no available motors of any kind for Soyuz and the rheostat Konvas never had any sync motors made originally) . 

I started with the 16mm Kinor motor last month and I'm refining the analog control electronics and fine tuning the code now. I was just thinking, is there lots of people out there who could use a customisable sync sound motor on their camera and if so, which exact camera models would be the most in demand?

If there seems to be some common interests then I could take them into account when developing my own motor project and it might be easy to make custom solutions for other persons cameras as well.

---------

What would be the absolutely mandatory specifications for this type of motor? I am aiming for +/- 10rpm accuracy at the moment but we will see how accurate the diy solution will be when it is fine tuned for the specific motor and camera model. That 10rpm accuracy would be about 1 frame drift for every 2.5 minutes of footage shot which should be usable for sync sound uses in indie films which have relatively short takes (a minute per take for example). My current design for the Kinor16 motor will have 6 different preset speeds and it uses the original pilot tone generator just like the Olex crystal sync modification does though my design is not as sophisticated or accurate (one gets what one pays for :) the Olex motor is better and my design is cheaper). 

- what type of camera and "wild" motor would most urgently need a digital speed stabilising system like this one?

- how accurate the speed needs to be. how much it can drift to be usable? I am talking about minimum specs which would enable practical use of the system, NOT about how much would be nice to have :)

- how much it can cost, in case there seems to be so much demand that it would be doable to do for example a dozen or so of these? 

- how much the end user can assemble by themselves? is a parts kit with pre drilled circuit board enough (needs soldering and a little bit of tuning) or only fully assembled board would do?

- it is very clear from beginning that this type of product needs to be user installed to be a viable option. It would not be economical to ship cameras and motors back and forth between continents, that would ruin the whole point of this type of motor solution 

- what kind of inputs for the encoder which is attached to the motor. My current design uses the pilot tone generator signal coming from the Kinor motor but for other cameras I will use either a encoder disc or magnetic sensors for rpm feedback. 

 

To answer the original question I asked when starting this thread: 

THERE IS NO DEMAND FOR CUSTOM SYNC SOUND MOTORS.   or more specifically, there is no demand for any kind of custom sync sound motors which would have any commercial value. These are interesting projects but most people making them seem to be just very interested making them just for the sake of it, OR they are selling other camera repair services and the Crystal Sync motors are just a way to get more customers for them.

For these reasons I am only developing stuff for my own use from now on. If the systems happen to be useful for someone else, then it is of course possible to make one or two crystal sync motors for others. But I don't have high hopes on that. 

Maybe I am just getting tired of the continuous bashing and disinformation and reverse engineering and everything. The original idea was to help people to restore their old non-working cameras to full working condition with updated electronics and everything so that they would have more tools available to shoot great art pieces on film. Maybe I was just too idealistic or something. And I have learned the hard way that it is not the best idea in the world to try to help people all the time. You will just get yourself burned in the process and not getting much in return. 

There is endless possibilities available but no one wanting to use them. That is how I see it. 

By all means, let the film die then. Just shoot digital if that is the only medium which is allowed to evolve, the only medium where it is allowed to have new tools and ideas every year and out of the box thinking is encouraged to get new end results. 

Shooting on film is the thing of the past because no one is willing to let the format evolve to something else which it has never been before but which it very well could be.

Basically your own fault then.

I think I'm going to continue my ROV project for a while and then shoot some film again. Concentrating on my own projects from now on. Not trying to be some kind of childish hero who would save all the unusable film cameras out there. That was a stupid idea anyway :)

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Aapo, don't let yourself get down by this. My experience is That most people can't imagine a hypothetical product enough to get really hooked. Once you have a fully working solution, with all the kinks removed and bugs fixed, a manual, nice photos and maybe an example video, this will change. 
 

See how Kickstarter works. There is nothing but semi pro videos, mellow piano music and often pretty brilliant marketing claims. A scale of yummy pledges makes people not want to miss out. And at the end, some goon collected a lot of money, runs with it and never delivers. And you know what? Most "customers" forgot about their contribution and don't even miss their pledge. 
 

I guess that's just how capitalism works... ¯\_(ツ)_/¯

People seeing a prototype strip board with bodge wires on a messy workbench doesn't sell. It does gain interest, but not enough to make a commitment. 

My recommendation would be: Keep going. Don't think product. Think about what you want to achieve for yourself only. If you feel for that, share your thoughts and see what others reaction is. Feel free to ignore it. Harvest the gems that might have been brought up. Involve others only as much as you feel comfortable. 

Only then, when it works for you and you are 100% happy, consider making it a product. If you don't feel like productizing, you can still make it open source. That's my absolute favorite way to go. It is by far the most pleasing... for me, at least. 

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  • 1 month later...

I will probably concentrate more on the ROV project and will explore the possibilities of building simple virtual production systems too. Both can use the skills gained from these crystal sync projects and will probably be much more rewarding to do :) 

anyway, I am still working on the following Crystal Sync modifications with free schedule. The Konvas15EPSS is definitely completed pretty soon though because I have all the boards and software ready and will just need to assemble it and fine tune the user interface.

- Konvas 15EPSS (almost completed, I will post images when it is fully assembled and ready to use) 

- Leicina S and SV (probably later this year)

- Kiev 16 UE  (probably later this year)

- Soyuz US3N  and Kinor 16CX-2M (for my own use only when having more time)

- Cinema Products CP16 and CP16R  (for my own use but if anyone else is interested please let me know)

- Eclair Cameflex  (sometime later. might be that I will just adapt a modern motor to it and modify that to crystal sync instead because the original motors are not very optimal for adaptation)

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10 minutes ago, Friedemann Wachsmuth said:

What does "ROV project" stand for?

basically underwater drones which are remotely operated via cable and have varying amount of independency. cameras etc. onboard. There is lots of interesting stuff to design in the navigating and communication systems of them 🙂 it helps a lot that I scuba dive and am able to test the system components separately underwater by myself in controlled depths (and I am able to dive the ROV back if it gets stuck for some reason). The water pressure is a signifiant challenge in these underwater systems and visibility is often poor here so I am intending on designing a suitable sonar system which the ROV can use for manouvering

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  • 1 month later...

If anyone is interested about the progress of my projects, I am uploading videos to my youtube channel every now and then ( https://www.youtube.com/channel/UCRQ4FduL9HyTBzX34CDtY4A  ) and also updating the camera specific threads on the "Camera Systems and Formats" forum section .

This thread is a dead end so no sense to post anything here anymore :)  

I am currently working on some brushless designs too (the brushless motors are handy for some designs when for others it makes sense to use brushed motors. depends on what you do). It seems that some of the newest stuff may have limited amount of commercial value which is why I won't talk anything about those projects before they are finished. 

So lots of stuff happening, I am just seriously limiting what I want to post here on the forum or anywhere else. 

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