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ALCS Single-Speed Crystal Controller for CP16R


Aapo Lettinen

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I am developing a single speed Crystal Sync controller for the CP16R which replaces the original circuit boards of the camera which are often corroded or otherwise broken. So the new controller allows restoring old cameras which have broken original electronics.

The original electric motor and all the original mechanical parts of the CP16R are needed. The original motor is of a non-common size and replacing the motor itself would make the kit too expensive to be practical... so be sure that the electric motor itself works in the camera.

It is a modular system with the basic kit costing 400usd + shipping and can be user installed. One would get a discount if ordering more than one kit.

The basic kit has one internal speed (either 24fps or 25fps, is user switchable if the camera is opened to change dip switch position) and does not have a footage counter (but a separate footage counter module is coming soon if getting at least 2 orders and can be installed later if it is needed. the separate footage counter costs 150usd + shipping) . I am developing a shutter parking feature too but it may not work 100% accurately all the time (should work pretty well though in most situations so should not be an issue).

It is possible to input a external speed signal from a special controller which can be purchased separately (different style of controllers can be made. Variable speed and lots of different crystal speeds possible. prices range from 150usd to 300usd depending on the features needed).

I am currently making two base kits for a customer and will likely ship them in September2022.    Additional modules like add-on footage counters etc. are possible to deliver from November2022 onwards.

If others want to order this 1-speed base kit for the CP16R from the first batch, let me know in August so that I can assemble the necessary amount of kits to assemble and ship them at the same time. The next batch would probably be in Autumn2023 so I would like to assemble as many kits as possible in 2022 so that anyone needing a kit would get it in reasonable time ?

 

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the current design has a completely new tachometer sensor board so that one does not need the original tachometer sensor either. I was unsure at first if the original sensor would be useful to keep around but it is just easier to replace the whole sensor board with a new one because it makes routing power to the motor much easier.

I included a very simple inching button to the design so that the user can run the motor at a very low speed (can be user adjusted using a trimmer potentiometer if the camera is opened and is ideally set to the lowest setting the camera can rotate on reliably without stopping intermittently) . The inching button can be used for rotating the mechanism just a tiny bit at a time by short pushes which should work pretty OK for repositioning the shutter if needed.

I will probably send most of the boards to manufacturing in August and can run some tests when getting them back and assembled.

Let me know in August2022 if wanting to order these one-speed CP16R crystal sync kits and if you are interested in the additional modules like the footage counter etc ?

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CAD designed the new tachometer circuit board today and will continue work on the new back panel and the main circuit board.

I made the plans for the separately sold new footage counter board as well. Will need to figure out a good place for the footage counter controls (reset button and the footage amount selector) but the footage counter add-on should be available in September2022 (let me know early on if wanting to order the footage counter so that I can reserve enough components to assemble them all in one batch) .

A quick note on the new tachometer board: it completely replaces the original tachometer circuit board BUT the small aluminium block part used for mounting the original tachometer board in the camera IS absolutely needed as well as the original screws!  so you will get a completely new tachometer board but don't throw the small aluminium part and screws away because you will need them when installing the new board and it would be very very frustrating if losing the aluminium block as it would be surprisingly expensive and difficult to manufacture a new one as it has to be machined from solid aluminium (a 3d printed would not work as it would not be sturdy enough for being reliable in the application). Same goes with the other screws from the original camera as I am making the replacement boards and replacement back panel to be mounted using the original screws of the camera and no screws are included in the installation kit.

At least make sure that you have saved the screws used for mounting the tachometer circuit board including the small aluminium block as well. the screws for mounting the back panel and for mounting the original circuit boards and the summer are needed too. As well as the ones used for fixing the cable connectors to the bottom of the camera in the motor compartment. If any screw is lost at this stage, you will probably need to find a replacement for it before being able to install the 1-speed CP16R crystal controller to your camera...  so a quick heads up that if important screws are missing from your camera, it may be good to start looking for replacements now to have everything ready for the conversion ?

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Drafting the back panel design! 

I am cad designing the back panel but have to test out the fitting multiple times and especially the connectors etc. that the back part of them fits inside the camera nicely as there is lots of restrictions inside the camera. The easiest way to do this fitting is to print out the design draft to cardboard and then just install all the connectors and screws and test it out!

As you can see the back panel of the Single Speed CP16R controller will be very simplified. Just the connectors one needs and the switch to select between the external speed input and the internal crystal sync. I reserved a small space where the user can write down what the internal crystal speed is set at ( either 24fps or 25fps) as it can be user switched relatively easily if opening the camera but typically one does not change it very often so it is typically set once and then one writes down what it is for that other know it too.

The person installing the system may choose to install additional run switches to other places in the camera and choose their favourite location for the inching switch (I will probably install it under the lens mount on my own camera but other positions are possible too) so no run or inching switches are installed in the back panel. I don't leave any spare room or holes for them either because it would be difficult to lightproof unused switch holes and there would be a large risk of light leaks then. The back panel is not a great place for a run or inching switch ergonomically so I decided one definitely does not want those switches there ?  One can control the start stop from the EXT connector as well so a external wired start stop switch can be easily made if needed. 

The main circuit boards are installed on the backside of this panel by me and the necessary cables installed to the connectors so that it would be as easy as possible to install this system to the camera with only basic tools and quick tutorial ?

I will include some spare connectors for the EXT and PWR connectors so that the user can make custom cables easily if needed.

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And because someone will ask it anyway:  YES it is possible to connect the power routing in the camera so that both the PWR power input connector AND the original onboard CP16R battery can be used for powering the camera. I will include a solution for this but it can vary if the person installing the system wants to use this option or not.

The back panel colour will still be determined but it won't be white like that printed mockup is ?

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I sent the circuit board bases to manufacturing now as well as the first version of the back panel. The back panel will look very neat in its final finish, will post images when getting the final versions back to me ?

I should get the first versions of the boards and the back panel from the factory in about two weeks and can then start assembling the prototype. I already know it works as I have based the software and hardware on my existing crystal sync designs (this is, I think, about the 50th design I have made so far), so it is 100% sure I can ship the final installation kits in September 2022 as originally planned for.

Just let me know ASAP if you are interested in ordering one as I can assemble more kits in the first batch if there is enough interest and you would then get it much faster ?

 

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More information about the separately sold new internal footage counter. The counter costs around 150usd + shipping and can be installed to the camera afterwards if needed so it does not need to be purchased at the same time than the main installation kit.

- the counter has its own summer and a possibility to wire a external LED light to it... the counter has its own current limiting resistor so it is very easy to wire it to a normal small led directly as there is no additional components needed. One could wire it to the original viewfinder Leds of the CP16R if those still work, or just add a new 3mm or 5mm led to the desired location in the camera body.

- the counter value is saved into internal memory and stored during a power loss. No backup batteries needed like in the original cp16r circuit board.

- the kit includes some basic switches and some wire so that the user can route the footage amount selector and the counter reset button to the desired location in the camera body and parts included to make it possible to select between 200ft and 400ft footage lengths. It would be possible for the user to change the counter mode so that it accepts a 12-position rotary switch for selecting footage amount but the switch is not included because it is too expensive to manufacture for such a low cost system and most users would not need it. I will include instructions how to make a suitable selector switch using a rotary switch and a resistor bridge but as said, I will only include parts for the two position selector as it can be installed in place of the original footage selector and makes the installation most convenient ?

- I am experimenting with a feature which allows using a very basic 4-character 7-segment Led display with the footage counter to show the footage amount it has calculated in meters. There is no room anywhere in the camera body to install a display like this unless installing it to the side door of the camera needing to cut out the aluminium-magnesium body making it diffult and time consuming. but if it seems to be a practical feature to have a display possibility like this I can include a suitable display in the kit and the user can try to figure out how it could be installed or if it is necessary for them at all. Not promising this feature would be in the final counter design but it is possible so wanted to mention it anyway ?

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In the basic CP16R 1-speed installation kit there is already a frame counter output from the EXT connector which gives a pulse for every 10 frames shot. This can be used with external counters (can be made by me either separately or be inluded in external speed controllers. OR people can make a Arduino system for this external counter use if being handy enough with Arduinos) so there is always a way to use some kind of display device to show the amount of footage shot.

If using a external counter it would need to be plugged in all the time when the camera is used whereas a internal counter would be more compact and would not need to be remembered to plug in before shooting. So there is pros and cons but I am pretty sure the end user would be very happy with the system no matter which counter option is selected and how it is installed ?

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Would there be any utility in re-assigning the existing internal film compartment 200ft/400ft selector switch as the EXT-  INT CR selector and re-assigning the switch position in the new rear panel as the studio run switch? 

If the existing EXT -INT CR switch is hardwired to the circuit board then do not fret about changing it. Longer wiring runs to the switch within the film compartment might also introduce interference from the running drive motor. 

The original parallel wiring arrangement for the news cameraman's press on - press off run button on the front handle and the studio run switch on the rear was default with an option offered of serial switching with the rear studio switch as the master. 

Unless someone actually wants to install a video tap, the optional electronic footage display might be accommodated where the video tap hatch is on the front upper surface of the camera with the same risks of interference being generated by the running drive motor.

It is looking good. 

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13 minutes ago, Robert Hart said:

Would there be any utility in re-assigning the existing internal film compartment 200ft/400ft selector switch as the EXT-  INT CR selector and re-assigning the switch position in the new rear panel as the studio run switch? 

If the existing EXT -INT CR switch is hardwired to the circuit board then do not fret about changing it. Longer wiring runs to the switch within the film compartment might also introduce interference from the running drive motor. 

The original parallel wiring arrangement for the news cameraman's press on - press off run button on the front handle and the studio run switch on the rear was default with an option offered of serial switching with the rear studio switch as the master. 

Unless someone actually wants to install a video tap, the optional electronic footage display might be accommodated where the video tap hatch is on the front upper surface of the camera with the same risks of interference being generated by the running drive motor.

It is looking good. 

Yes it would be possible to wire it differently as the switch on the back panel is intentionally made separate and not soldered on the circuit board. The start stop switch needs to be momentarily acting one so one would move the int-ext selector to the inside the camera and then add a separate non-locking closing push button in place of it on the back panel.

The 6-pin accessory port has a start-stop pin too so it is possible to wire a external start stop switch from it very easily and ideally one would place this switch to the pan handle. The start stop switch would need to be a non-locking push button to function properly.

One could choose to wire the inside functions of the camera differently than originally intended and to add multiple start stop switches or inching switches on various places if that would be necessary. Inching is not available via the 6-pin connector so it has to be a button on the camera body though the user might choose to add his/her own output connector for it on somewhere else in the camera body if external inching button would be needed. The inching speed is non sync and bypasses the crystal controller completely so that one can make very short inching pushes to reposition the mirror if needed. this is actually surprisingly easy when getting used to it and if the inching speed is set very low (it is user adjusted using a trimmer potentiometer on the circuit board behind the back panel)

I will get the circuit boards in about 1.5 weeks and can then show it better but here is the cardboard mockup of the back panel showing how the int-ext switch is positioned and how it looks like in proportion to the circuit board next to it

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or one could make a frankenswitch by installing a small push button switch directly to a compatible 6-pin connector without having any cable in between. It looks ridiculous but can actually be handy in some situations and would at least be useful as a backup ?

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The news cameraman's pushbutton switch would also have to be changed to the momentary pushbutton style. 

An internal inching switch would be handy for rolling the film slowly to check the loop before closing up after loading but is not really necessary. Most folk rotate the common sprocket with its manual inching knurled rim then roll the camera with the existing switches.

My personal preference would be to preserve that internal switch position for the EXT IN / INT CR selection.

Edited by Robert Hart
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I will probably install inching switches on my own cameras to the small panel which is directly under the lens on the front of the camera. this way it can be easily accessed after each shot if the mirror needs repositioning. will need to test out if one run switch could be useful to position there too as it should be easy to access with the left hand when shooting I believe.

it would be easy to install multiple switches to the camera body, just need to drill a hole to the original panel/cover the camera has in place and then route the wires inside the camera so that they don't catch the moving parts in the motor compartment. Needs some soldering and drilling and zip ties but should be very easy to do when knowing how to connect them ?

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If your external power system would also operate from 14V V-Lock or AB camera batteries via a D-Tap cable, there may be some utility in using an industry-standard 4-Pin XLR socket for the external power-in. 

I understand that one reason for the original 20VDC was chosen so light aircraft 24VDC power could be accessible.

Edited by Robert Hart
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if using a footage counter with the 4-digit led display, it would be possible to install a small box on the outside of the camera housing the display and drill a hole to the body for the wires (so that it would be fixed to the camera body. for example on the camera door or to the motor side of the camera body) . It might be possible to fit one over the viewfinder if there is enough room for it, but I suspect the display would be slightly too thick to fit there completely and might be a bit challenging to proof for light leaks. So the easiest way would probably be to install a small separate box permanently on the camera's outer surface and route the wires through a drilled hole to the footage counter board so that no wires go outside the camera and the add-on box is just a part of the outer surface of the camera so to speak ?

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3 minutes ago, Robert Hart said:

If your external power system would operate from 14V V-Lock or AB camera batteries via a D-Tap cable, there may be some utility in using an industry-standard 4-Pin XLR socket for the external power-in. 

I think the camera motor itself can barely do 22 to 24fps with 13v or 14v so it might be risking sync stability to use low voltage battery with it. I will test it too when getting the circuit boards assembled but probably I would use something like 16v or 17v minimum for shooting sync sound with the camera.  the likely optimal range should be something like 18v to 23v or so I think.

if one would add a separate external step down converter between the battery and the camera, then one could use anything from maybe 24v to something like 36v or so as a battery and just adjust the down converter so that it provides about 20v for the camera all the time no matter what the actual battery voltage is. A down converted like this would cost something like 15 or 20usd on eBay if using the lower quality Chinese ones which should work perfectly well in this application

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I am designing a external speed controller at the moment which is compatible with this Single-Speed CP16R system.

the external controller connects via cable to the 6-pin accessory connector on the back panel of the camera and the controller has all the most used crystal sync speeds available (for example 23.976, 24.00, 25.00 and many others) as well as a variable speed knob for making speed ramps etc.

The variable speed works on the range of from 5fps to 50fps and is adjusted using a knob so one can do manual speed ramps with it too if needed ?

It has a basic 4-digit led display and I will probably add some kind of very basic footage counter to it too depending on how well it works in tests.

The controller is compatible with both my Eclair ACL 16-speed motor and this CP16R 1-speed motor. It is also compatible with some of my other camera modifications if they use a compatible pulses per frame number. One can change the camera system setting by opening the front panel of the controller and flipping dip switches on the circuit board. It shows on the display on bootup what system it is set on so the panel does not need to be opened if unsure about the setting and you probably only need to set it once (or let me set it for you when assembling the controller if you already know what camera it will be used with).

The targeted price point for this external speed controller is 220usd + shipping and it should be available in October2022. It needs to be assembled in batch sizes of 5 or more so let me know early on if wanting to order one so that I can collect enough orders to make a batch with minimal waiting time ?

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Aapo: 

I think I'd strongly suggest you use a smaller selector switch..

That long toggle seems awfully close to the exposed bottom edge right at the back,  it feels like it's just crying out to get damaged from being pushed back on a shelf or dropped into a case at the end of the day.

Maybe some kind of small rocker switch.

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38 minutes ago, Steve Switaj said:

Aapo: 

I think I'd strongly suggest you use a smaller selector switch..

That long toggle seems awfully close to the exposed bottom edge right at the back,  it feels like it's just crying out to get damaged from being pushed back on a shelf or dropped into a case at the end of the day.

Maybe some kind of small rocker switch.

It is possible to change different kinds of switches to the panel if needed. Additionally it would be possible for the user to use a dremel style multitool to cut the switch lever shorter so that it is less exposed. Personally I can easily use the original version and the switch is very easy to replace if needed.

There is a very limited warranty on the system because the end users install the system by themselves, and are allowed to do minor modifications to it, change swithes and route them differently, etc. As long as no IP is stolen, no copyright information removed or falsified and the io or power connector polarity/pin order is not altered (so that it is still compatible with original accessories). Installing additional connectors or switches to the camera body is allowed.

Making square shaped holes for switches or making protective shields for them is pretty difficult for me to arrange so every switch and connector needs to have round mounting and thus rocker switches don't work well in this application. 

One other option is to install the switch inside the camera in place of the original footage selector like Robert suggested. 

The int/ext switch gives a signal to the electronics to change the "listening input" for sync reference signal. So the actual speed signal does not go through the switch, it is just a floating pin which is shorted to ground if switch is on and then the electronics know to change to the external speed input. So the sync would work with a faulty switch without issues as long as it is know which state it currently has (floating or gnd). 

So it is possible to shoot with the camera with the switch broken if needed.

I made it this way on purpose to make the system more reliable :)

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Here is the final back panel version without connectors and surface finish. I was originally going to make it black but had to choose this natural version for technical reasons and because it is way more durable. Will install the connectors to it when having time to drill the holes to the full diameter.

The panel will have a lacquer finish when I have drilled the holes and the colour will look better then. The panel is made of fiberglass material and is very durable, on par with the original aluminium back panel.

I demonstrated how one would write the chosen internal crystal speed on the panel. If one would change it often, it would be wise to put a small piece of transparent tape over the marking spot, then mark on the tape OR adding a small piece of white tape over it like camera tape and mark on that. Then it would be easy to remove and change marking without damaging the lacquer on the panel surface.

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I designed a new tachometer sensor board which fits in the place of the old one. It was very time consuming to design and is a bit tricky to assemble so it takes some time but here is demonstrated with a unassembled board how it fits to the camera.

The new tachometer board has a small preamplifier and it would allow to use it with other types of control systems as well. Not that there is any other systems available or in development for cp16r but it is good to know that one could easily get a standard pulse signal out of the board for other systems if that would be needed.

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Good progress to see happening there and keeping it simple. There will be purists who wish to preserve cameras in an unaltered state. There are probably enough left to satisfy them. For folk who want a CP for its original robust and reliable utility, the single speed option will suit fine. This one's beating heart awaits its new pacemaker.

CP CAMERA.jpg

Edited by Robert Hart
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In regard the vulnerability of the nagra-style switch and the PCB, I had a similar concern. It should be east enough to protect with a C-channel surrounding the switch and attached horizontally with the lower panel screws. Whatever breaks that will break the case and by then all bets would be off anyway.

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I tested if it is possible to shorten the switch lever by cutting a part of it off and it is definitely a possibility. If taking about half of it off it is much more protected and should not take more than 5 minutes to do. An alternative is to install the switch somewhere else on the camera body and either drill the hole on the back panel a tiny bit larger to fit a start stop switch or inching switch there, or to cap the hole entirely if no switch is needed on the back panel. Users can choose to make diy c-channels which are fitted under the switch's locking nut (I think one could take a small piece of stainless steel sheet, drill a hole in the middle and then bend it using some tools to form a pretty sturdy c-style protector. Finishing the edges and making it to look nice would take some time and effort but should otherwise work pretty ok.

the back panel has a thin metal film on the backside which acts as a primary light sealant and capping the switch hole would be possible for example by attaching a small piece of aluminium tape on the backside of the panel over the hole so that the aluminium would be on the same side than the panel's metal film to have the best light sealing possible... and then fill the hole with some material like epoxy or similar stuff which protects the aluminium tape from punctures.

I will try to find some thin neoprene foam sheet or something similar material which can be used between the panel and the camera body to seal light from the panel's edges and to suppress internal reflections and some running noise... just like the original back panel had. This would be a secondary layer of light leak protection. The metal film is the primary one as it is extremely effective preventing any light shining through the back panel as long as the metal film is not damaged. I will include some kind of light sealing material with the kits but need to figure out the exact contents when getting the prototype working and installed to the camera

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I will have TWO extra installation kits available in September from the first batch. Please let me know ASAP if wanting to order them. I will wait for light sealing material and some minor parts to arrive and will then start to assemble the boards.

 

An additional internal framerate added: 

I had an additional switch combination available on the DIP switch so I added a fift gear/speed combination to be available as the set internal speed. If the camera has 24fps gears, then it is possible to set 23.976fps as the internal speed. This is only available for 24fps gears.

So there is a total of FIVE different gear type /speed combinations the camera can be set at if it is opened and the DIP switch combination changed:

24fps gear in the camera:    23.976fps / 24.00fps / 25.00fps

25fps gear in the camera:  24.00fps / 25.00fps

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This is a cardboard mockup of the external controller compatible with the CP16R 1-speed system.

It has a basic footage counter and camera controls. Speed is adjustable from 5fps to 50fps in variable speed and the crystal speed is adjustable in steps which include the most used crystal speeds including 23.976, 24.00, 25.00, 29.976, 33.333 and so on.

The controller is compatible with botht the CP16R and the Eclair ACL motor I am building. Motor type is changed by opening the front panel and changing DIP switch combination. The 24fps/25fps gear type of the CP16R is set using the DIP switches as well. It only takes couple of minutes so it is very easy to do.

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Please note that the CP16R does not have Phase function so the Phase switch does not work with it.

The external controller uses a separate power source and cannot be powered from the 6-pin connector of the camera (the 6-pin connector on the camera does not have power output for electrical safety reasons) . The external controller will have a separate power connector and one can easily arrange power for it using a separate small battery.

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I assembled the new tachometer sensor boards and the power distribution boards today. 

Next I will finish the software so that I can assemble the main circuit board and then the system is complete.

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Here you can see how the power distribution board is mounted on the bottom of the camera. It allows using two different power sources and the highest voltage source is automatically used to power the camera. One would wire the onboard battery to one of the inputs and the external power connector to the other one.

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One would drill an additional hole to the camera body to add secondary mounting point to the power distribution board. this drilling is pretty easy to do as long as one first protects the camera mechanism from metal chips and dust by taping plastic bags for protection which only exposes the drilling location so that cleaning is easy

Edited by aapo lettinen
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