Watching the video on YouTube, I realized that on the radiator that cools the camera sensor, it is flat without ribs that would help the sensor to cool more intensively. Now in the 3D program I tried to develop external cooling for the camera with a more powerful cooler (4000 rpm 60 * 60 * 15mm) with the installation of a dust filter and cooler protection. But the question arose of how you can add fins to this radiator or how you can replace it with the same size but with fins
https://vk.cc/bX9SD0
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I am also still trying to figure out how to actually make this a practical cooling solution for daily use. My current best bet would be 3mm Heatpipes, a somewhat modified Cooler Block ( a bit "fatter" cooler block with thinner Thermal pads, maybe also larger in size with fins. And yes, fins will fit. Not with the Same Size block tho, needs to be larger, but there is quite some Empty space for that between the Circut boards, needs to be an Flat cooler) with two 3mm Heatpipes ( The ones i got are rated for 18W Heat load at 70°C) which will connect to some kind of External Contact surface which i want to mount on the Bottom Of the Camera like a camera cage. Doesnt need to be huge, can have a rater Small footprint while still allowing access to the Battery if needed. To this Outside Copper Surface i will be able to mount Air coolers or Waterblocks, even Peltier modules would then be possible, because outside the Camera i will have plenty of space, but will still be able to get the external more beefy cooling solution off quickly if i need a smaller Camera to move very Quickly when shooting (without first needing to open the Camera and Replacing the Cooling block on location). .
This is so far the most promising idea, because it still is a "hybrid" approach to cooling, meaning i can go full Watercooled or add any very beefy external cooler of any kind very easily, but the Camera will still work as-is as a Standalone Unit if needed (as the block itself still does the same work as bevore and the Heatpipes wont obstruct the usual cooling in any way, if any they improove heat transfer across the Block and add surface Aera), also its a drop-in replacement which doesnt need extensive permanent modification of the Camera itself and can be easily reverted to standard configuration.
Its also is a very capeable cooling solution at the Same time, it should be able to get the sensor quite a bit down in temperature if not even pretty close to Room Temp (if the Heatpipes still can transfer enough power at those Temps and you add an Waterblock or Peltier Module).
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Now for your idea, i also allready tried this ( if i understand correctly you are trying to make a shroud for the front air intake holes to push More air in with an powerfull fan), force feeding the Camera with more air, and it does improove Cooling, yes, but not by all that much. You can only get so much air inside, and at a certain point, the Internal Fan will even start to limit the amout of air you can Push through. so if you can Manage to get some Serious increase over the Current amount of Airflow (like order of magnitude kind of increase, which would most likely need the internal fan to be removed and also some way of preventing the air from exiting through the Bottom intake holes, by either a second intake Shroud or closing it), it might be worth a try and can actually improove Sensor Temperatures by quite a bit, but with only a single fan i assume it would propably be hardly noticeable. For reference, i used an 14krpm 40x40x30 Server fan, which pushes some Serious air and also has plenty of Air pressure, not sure which exact fan you are planing on using, but even with that one i could only get like 2 to 4°C improovement (didnt make a fancy shroud, to be fair, had a way more sketchy setup), and i am not sure if that would be worth it for me, camera sounding like an actuall Jet Engine (this small server fan is really loud, against this one, even the Stock Chronos fan seems very reasonable and quiet.
https://forum.krontech.ca/index.php?topic=521.msg3922#msg3922 ). Now 2 to 4 °C is still something, but if i would do something like this i would maybe go with an even More Powerfull Fan to make the Effort at least worth it, like some of the bigger server Fans, which can push quite some air, those could get the Camera down quite a bit in temps.
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In terms of external cooling solutions involving air, i guess easiest and most effective one would be to just get yourself one of those Moveable air-conditioner Units and making some kind of "Blimp" for the Chronos, but not for Noise like in the old days, but as an Air Shroud, in which you would feed the Air-Conditioner Air, going at full blast, putting out 15°C or Colder air. (for Reference:
https://search.yahoo.com/yhs/search?p=arri%2Bblimp ). I think this would be way more effective than your idea, considering cooling solutions which wouldnt need to fumble with the cameras internals. Because a thing i also didnt understand at first, the Copper Cooler experiment helped me a lot to understand it better, is how the current Thermal design actually works. This Small Cooler Block made from Aluminum attached to the sensor isnt really meant to dissapate all that much heat directly into the Air, but rather to transfer it into the Metal Case/ Body of the Camera, and the Fan itself seemingly doesnt mainly cool the Sensor itself. The Fan (as far as i understand it and how it actually seems to work in the end, not absolutely sure about the intentions when designing the Thermal solution for this Camera) seems to mainly directly cool all the other internal Components which are not connected to the Case by contact pads or heatsinks, and at the same time provides some base forced Airflow through the Case, which in turn happens to Cool the Case down a bit. So actually this is more of a passive Cooling solution (talking about the Cooling for the Sensor itself) than an Active one, because it seems that for extended runtime of the Camera (everything longer than 30 or 60 Minutes), when the Thermal Mass of the camera reached thermal Equilibrium, the Camera outer Surface seems to do quite some of the Cooling, if not the mayor part of it. The Fan sure helps to cool the Metal of the Camera Case down a bit, because any kind of Airflow will massively improove cooling in such a situation, but considering all of the above said things about the current thermal design of the Camera, i propably wouldnt go and try to just push more air through the airpath inside. The current airflow with the Stock fan is somewhat at a sweetspot, where it still does help quite a bit with cooling, but doesnt need utter overkill Fans and Shrouds, from this point on, you will allways need to up your Airflow Way more to still see little improovements in cooling for the Internal Airflow. As you allready said, when pushing those amounts of air, as would be needed to considerably lower Sensor Temps from just that, dust buildup would propably become an actuall problem. Because the Small Sensor Cooler block itself doesnt really do all that much in terms of Air Cooling surface, might as well cool the outside of the Case better with additional fans or bolt some heatsinks onto the outside. Pushing more air through the Camera will keep the Sensor Cooler for the first 5 Minutes of use, but for longer runtimes above 40 Min, cooling the outside better will propably outperform internal Airflow with way less effort. Now Considering that the Outside Surface is doing a lot of the Cooling, blowing really cold air from an Air Conditioner Unit at it would not only increase temperature difference between outer Surface and Air, thus increasing Dissapation, but also would add considerable outside airflow. An AC Unit is Still Pretty Bulky tho, not the kind of thing you want to have to bring to any shooting location, except for Studio work, where the camera will be setup all the Time and doesnt need to move all that much.
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Still kind of a difficult topic, because no matter the amount of Airflow you will be able to generate, as of now the Cooling solution still has the problem that the thermal resistance between the Sensor and the Case is still pretty high, meaning even if you could Force the outside Of the Case to 22°C Room Temperature with massive Fans or something, Sensor would propably still sit at something like 30 to 35°C (or even worse possibly). So sure, this will work for the Average user propably, but the thing is, that this sensor just has way more potential Image Quality available, which needs a better cooling solution somehow. Now if you can even get it to 35°C on the Long runtimes, thats allready a huge win, but everything below that will almost sure need Internal Modification or use of an AC Unit or something like that.