Split Cameras

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Could you draw a little diagram showing the hookup points on the fixed or adjustable BEC direct to the cam and batteries....I'm electronically challenged

The pictures on Amazon can do better than I could. Basically you have the positive form the battery (VBAT) and its ground. Then on the bottom you have the ground and positive 5V going out to your device.



1614608777356.png
 
The pictures on Amazon can do better than I could. Basically you have the positive form the battery (VBAT) and its ground. Then on the bottom you have the ground and positive 5V going out to your device.



View attachment 452999
I'm looking at the picture you posted earlier showing the various devices...what kind of connectors are being used. It appears you have red/black coming out both ends of the split camera...I guess one end of the camera connects to the bec and the other end to the battery? That's what I was asking you to show.
 
I'm looking at the picture you posted earlier showing the various devices...what kind of connectors are being used.
I am not sure which specific picture you are referring too. The picture that I had showing all the devices I believe was the different batteries, BECs, and a wifi switch, no camera in that picture. I am using all JST connectors at the moment just for testing. In the end I will probably just solder everything straight together.

The BEC goes in series in-between the battery and camera. Taking any switch out of the loop just for simplification you get the below. The blue is the battery, greed is the BEC, and orange is the camera.
batt1.jpg

Now, My plans have changed a little and I now plan to add a voltage cut off circuit into the loop so I can use a smaller battery and just have it cut out when the voltage drops below 6v. Below shows the same with the voltage cut off circuit (Purple) and a switch (Gray). I got this circuit off Ebay.

batt2.jpg
 
I am not sure which specific picture you are referring too. The picture that I had showing all the devices I believe was the different batteries, BECs, and a wifi switch, no camera in that picture. I am using all JST connectors at the moment just for testing. In the end I will probably just solder everything straight together.

The BEC goes in series in-between the battery and camera. Taking any switch out of the loop just for simplification you get the below. The blue is the battery, greed is the BEC, and orange is the camera.
View attachment 453003

Now, My plans have changed a little and I now plan to add a voltage cut off circuit into the loop so I can use a smaller battery and just have it cut out when the voltage drops below 6v. Below shows the same with the voltage cut off circuit (Purple) and a switch (Gray). I got this circuit off Ebay.

View attachment 453004
Thanks very much Jason!
 
I’ve just completed my runcam setup. It’s a runcam split 3 nano with adjustable voltage regulator set to 7.2v. I’ve added an aluminum heat sink to prevent overheating which seemed to help when testing outside the rocket. While inside the rocket I left it recording with featherweight gps tracker and eggtimer quantum altimeter powered on and ready to test separation charges to ensure no signal interference between the electronics. All testing went perfect minus the camera overheating and shutting off after 17 mins of recording. I would be very interested to see what you guys have done to prevent this overheating. Pictured is my setup that mounts inside the payload section of the rocket with 1/2” hole drilled for the camera lens. Is it because of it being so enclosed? I’m lost on what to do with this thing to get it working correctly. It’s a shame that such a great quality camera is plagued by overheating issues.A489001A-69F0-4618-BA43-D55B0D80A601.jpeg
 
The heat sink will work if it can effectively dissipate the heat to the outside. For passive cooling, I think you would almost need conduction of the heat to outside of the airframe with a heat sink and maybe a large surface area. But, it's summer now and pretty warm outside too.
I think we would need a more active way of cooling, and that means including a fan and perhaps drawing/forcing cooler air into the bay.
When I was trying to keep a GoPro Hero Session cool in a 3" clear polycarbonate tube, I tried to introduce cooler air by using compressed air through a tube inserted into the camera bay on the pad before launch. (Note, the altimeter was not in this bay.) It worked OK, and the camera shutdown after it landed and before recovery. btw, the Hero self-heats to improve LiPo battery performance, but this is a problem for our applications.
Alternatively, perhaps add 3D printed air ducts (would create more drag on the rocket of course) and get the rocket launched asap.
Here's a link to a micro-sized air cooling fan: https://www.amazon.com/gp/product/B0866RPBM4
I'm going to get one for bench testing.
 
The heat sink will work if it can effectively dissipate the heat to the outside. For passive cooling, I think you would almost need conduction of the heat to outside of the airframe with a heat sink and maybe a large surface area. But, it's summer now and pretty warm outside too.
I think we would need a more active way of cooling, and that means including a fan and perhaps drawing/forcing cooler air into the bay.
When I was trying to keep a GoPro Hero Session cool in a 3" clear polycarbonate tube, I tried to introduce cooler air by using compressed air through a tube inserted into the camera bay on the pad before launch. (Note, the altimeter was not in this bay.) It worked OK, and the camera shutdown after it landed and before recovery. btw, the Hero self-heats to improve LiPo battery performance, but this is a problem for our applications.
Alternatively, perhaps add 3D printed air ducts (would create more drag on the rocket of course) and get the rocket launched asap.
Here's a link to a micro-sized air cooling fan: https://www.amazon.com/gp/product/B0866RPBM4
I'm going to get one for bench testing.
That fan is interesting. I’m using a 2200 mah 2s lipo. I’m curious if it would be ok to power that with the same lipo.
 
I've used a small sheet of Reflectix on the outside of the airframe in the summer because the SoCal deserts have really intense heat July through Sept. Tip: Never lay your rocket down flat in the Sun because it will get hot quickly. I'm a retired contractor, and we would place all tools at a 45 degree angle when you are using them outside (like pipe wrenches and even rebar). They do not get hot that way, and the same applies to rockets.

I was thinking a 1S LiPo to power the cooling fan. You could even twist the positive wire together with some tape and tuck in the air vent hole at the pad. I would never do that to arm an altimeter but may be a good solution to applying power in this case.
So, the first thing I would do is get the fan and a small 1S LiPo and run it on the bench. See how it does. Then, maybe in a tube with an inlet and outlet hole.

I've used aquarium digital thermometers to monitor the heat inside tubes exposed to the Sun to check temperature rise. Here's a dual temp probe I picked up on Amazon that has a probe that fits through a 3/16" hole. Great for monitoring two temps like inside/outside.
IMG_3576.jpg
 
I was thinking a 1S LiPo to power the cooling fan. You could even twist the positive wire together with some tape and tuck in the air vent hole at the pad. I would never do that to arm an altimeter but may be a good solution to applying power in this case.

Sounds like a good application for OverTheTop's magnetic umbilical (look at the very bottom of the linked post)
 
You can buy quite small fans and blowers. Here are a couple of examples:
https://www.ebay.com.au/itm/174672173956https://www.ebay.com.au/itm/392884148589
The axial fans move quite a bit of air but don't do so well against any backpressure. The radial blowers work far better against back pressure, but don't move as much air overall, generally speaking.

I ordered some just a couple of days ago. Some for our 3D printers, some for rocketry ;).
 
Do the 1080P split cameras have overheating issues? If not, I'm going to ditch my 4K for one of those. I'd rather have HD video of my whole flight as opposed to 4K video of it sitting on the pad until it overheats lol.
 
I did a flight with a RunCam Split 3 Nano. It was quite hot (approx. 90F (32°C) measured in the shadow) and the rocket was sitting almost 15 minutes on the pad in plain sun.
The main chip on the camera board gets quite hot, which is normall according to the manual. Ebay measures about 4'' x 10'' and no venting for the cam was provided except the vent holes for the altimeters.
I did not experience any overheating problem and the camera worked well.
I am convinced of the RunCam Split 3 Nano as it starts recording when you connect it to power up and stops recording when you disconnect it from power.
Power was supplied through a 2S LiPo with a magnetic switch.
 
I've recently acquired a Runcam Split HD (latest version, Split 4 no longer in regular production per their website) and have set it up with a dedicated battery (trying both 2S 430mah and 3S 1000mah) running through a BEC. The longest running time I can get so far is 4 minutes on the bench, starting at 70 deg F ambient in my shop - and with a 30x30 copper heatsink applied to the aluminum module cover, I can get 12 minutes (with 3S battery). Just curious if anyone has discovered a silver bullet solution to this overheating issue in the last 10 months? It seems odd that it would overheat so quickly (I'm not a drone guy so maybe there is forced air used to cool the module in those applications). Thanks for any new thoughts. Shame to waste a sweet setup for a small-space if it can be remedied.
 
What voltage are you supplying it through your BEC ? Just confirming that your BEC is outputting ~5V under load. I have not used the Split 4 (yet) but I have some experience with the Split 3. I attach a large custom heatsink directly to the chip. At 1080P 60fps the heat sink gets really hot. I can only imaging that the 4K version you have will get hotter still. And the aluminum cover (their version of a heat sink) they have added to the Split 4 makes means you can't access the chip directly. Adding your own heat sink to their cover like you have done is better than nothing but not the same as getting a large heat sink directly in contact with the chip. Also, high quality thermal grease is key.

Another trick is to configure the camera for minimal video file compression (which unfortunately results in the biggest file size) Compression algorithms require a lot of computation, which creates heat.
 
I am not currently shipping product but I hope to be again in the not so distant future. Take a look they at the link in my signature, I sell a camera mount with a molded carbon fiber ogive shroud. My shrouds use the Mobius Mini camera with the extension cable to point the camera out of the airframe and minimize the protrusion. Maybe they will give you some ideas.
Your security cert has expired, so I won't access it. You really should update it.
 
@MichiganJohn,

The other issue with using the RunCam Split series is that they were designed with drones in mind, mounted "Open Air". Also note that at least on my Split 4, the entire circuit board is covered in a conformal coating. That coating needs to be removed from the top of the main processor chip and thermal paste applied between it and the heatsink for max heat transfer.
 
I've recently acquired a Runcam Split HD (latest version, Split 4 no longer in regular production per their website) and have set it up with a dedicated battery (trying both 2S 430mah and 3S 1000mah) running through a BEC. The longest running time I can get so far is 4 minutes on the bench, starting at 70 deg F ambient in my shop - and with a 30x30 copper heatsink applied to the aluminum module cover, I can get 12 minutes (with 3S battery). Just curious if anyone has discovered a silver bullet solution to this overheating issue in the last 10 months? It seems odd that it would overheat so quickly (I'm not a drone guy so maybe there is forced air used to cool the module in those applications). Thanks for any new thoughts. Shame to waste a sweet setup for a small-space if it can be remedied.

I have the RunCam 2 and I had asked them at their support about running an external battery and they said no, it would cause the internal battery to overheat and you can't run it without the internal battery. It could actually catch fire. Personally I think this is a bad design but do not have the means to redesign it. It would be nice to have a couple hours of run time. Apparently these are meant for short duration videos from a drone or something, they don't take into account a rocket sitting on the pad for an hour before liftoff. I designed a radio controlled "Finger" to start my camera but haven't tried it yet. R/C radios will run for a couple hours easily especially when no servo action is happening. The drawback there is you can't be totally sure that the camera turned on... Just cross your fingers and hope!
 
What voltage are you supplying it through your BEC ? Just confirming that your BEC is outputting ~5V under load. I have not used the Split 4 (yet) but I have some experience with the Split 3. I attach a large custom heatsink directly to the chip. At 1080P 60fps the heat sink gets really hot. I can only imaging that the 4K version you have will get hotter still. And the aluminum cover (their version of a heat sink) they have added to the Split 4 makes means you can't access the chip directly. Adding your own heat sink to their cover like you have done is better than nothing but not the same as getting a large heat sink directly in contact with the chip. Also, high quality thermal grease is key.

Another trick is to configure the camera for minimal video file compression (which unfortunately results in the biggest file size) Compression algorithms require a lot of computation, which creates heat.

Thanks @Finicky, this was really helpful. I adjusted the video settings to 1080 and 'Low Quality' and was able to run it sustained for over 30 minutes on the bench, until I turned it off. The module got close to shutdown temp, but stopped a few degrees short when I elevated it off the surface a quarter inch. (Note to your question: the BEC is putting out 5.00 v under load)

I'm left with a couple new questions, not sure if you or someone else will know the answers, but:

1) Edit: disregard the following question - there is no 'lock out' when not using the aluminum cover - I had a failure-to-start a couple times with cover off, and assumed that was the root cause.
Is there a way to run the camera without the aluminum shield? I'd like to put a heatsink directly on the chip - not sure if I can 'short' the system somehow to get it to run without the shield screwed down. (The lowtech method would be to remove the section of shield directly over the chip).

2) How does choosing a Low/Med/High setting for 'Video Quality' impact the video - this is separate from resolution setting. And I don't see a compression setting to modify, per your suggestion - maybe it's not available on Split HD, or maybe the Video Quality setting is actually for compression? (Thought I'd be able to find this in RunCam documentation somewhere, but coming up short on their site and via using my google machine).

Appreciate the insights - already seems like it might be a usable option now.
 
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@MichiganJohn,

The other issue with using the RunCam Split series is that they were designed with drones in mind, mounted "Open Air". Also note that at least on my Split 4, the entire circuit board is covered in a conformal coating. That coating needs to be removed from the top of the main processor chip and thermal paste applied between it and the heatsink for max heat transfer.

Thank you @Tobor - helpful tip - will use it.
 
I have the RunCam 2 and I had asked them at their support about running an external battery and they said no, it would cause the internal battery to overheat and you can't run it without the internal battery. It could actually catch fire. Personally I think this is a bad design but do not have the means to redesign it. It would be nice to have a couple hours of run time. Apparently these are meant for short duration videos from a drone or something, they don't take into account a rocket sitting on the pad for an hour before liftoff. I designed a radio controlled "Finger" to start my camera but haven't tried it yet. R/C radios will run for a couple hours easily especially when no servo action is happening. The drawback there is you can't be totally sure that the camera turned on... Just cross your fingers and hope!

Yes I've had similar experience with RunCam4 - a couple of good flights at first, and then it's been hit or miss on whether it stays running on the pad. I saw a tip here, re turning it on then off then back on, so will try that going forward. But yeah, not the best situation if camera turns itself off after a minute or two. 😑
 
Thanks @Finicky, this was really helpful. I adjusted the video settings to 1080 and 'Low Quality' and was able to run it sustained for over 30 minutes on the bench, until I turned it off. The module got close to shutdown temp, but stopped a few degrees short when I elevated it off the surface a quarter inch. (Note to your question: the BEC is putting out 5.00 v under load)

I'm left with a couple new questions, not sure if you or someone else will know the answers, but:

1) Is there a way to run the camera without the aluminum shield? I'd like to put a heatsink directly on the chip - not sure if I can 'short' the system somehow to get it to run without the shield screwed down. (The lowtech method would be to remove the section of shield directly over the chip).

2) How does choosing a Low/Med/High setting for 'Video Quality' impact the video - this is separate from resolution setting. And I don't see a compression setting to modify, per your suggestion - maybe it's not available on Split HD, or maybe the Video Quality setting is actually for compression? (Thought I'd be able to find this in RunCam documentation somewhere, but coming up short on their site and via using my google machine).

Appreciate the insights - already seems like it might be a usable option now.
You are correct that Video Quality is not the same as Resolution. But both settings will effect heat output from the chip. Lower Resolution will result in less heat (at least in my experience). This is because you are moving around lower pixels/second of data while recording.

I know this is counterintuitive, but you want Higher video quality to get less heat (again, in my experience). The Video Quality setting implies video compression algorithms that are analyzing the video data in realtime and deciding what they can throw away. The highest quality setting performs the least data compression on the video stream, and this generates the least amount of heat. The downside is that the video files are big and you might run out of SD card space. But in my experience with a 64Gb or 128Gb memory card, the battery dies long before you run out of memory card space.

I believe the reason you were able to run for longer before you overheated is that you switched from 4K resolution to 1080P. If you leave it at 1080P and then switch to High Quality video you would hopefully be able to run even longer. But you are kind of losing out on the full "beauty" of 4K video if you drop the resolution to 1080P. Personally, I've always thought 1080P was good enough.
 
You are correct that Video Quality is not the same as Resolution. But both settings will effect heat output from the chip. Lower Resolution will result in less heat (at least in my experience). This is because you are moving around lower pixels/second of data while recording.

I know this is counterintuitive, but you want Higher video quality to get less heat (again, in my experience). The Video Quality setting implies video compression algorithms that are analyzing the video data in realtime and deciding what they can throw away. The highest quality setting performs the least data compression on the video stream, and this generates the least amount of heat. The downside is that the video files are big and you might run out of SD card space. But in my experience with a 64Gb or 128Gb memory card, the battery dies long before you run out of memory card space.

I believe the reason you were able to run for longer before you overheated is that you switched from 4K resolution to 1080P. If you leave it at 1080P and then switch to High Quality video you would hopefully be able to run even longer. But you are kind of losing out on the full "beauty" of 4K video if you drop the resolution to 1080P. Personally, I've always thought 1080P was good enough.

Thanks, appreciate the clarification.
 
I have a Split 3 and a Split 4, both of which have exhibited similar behaviour. I've found that two (2) approaches in concert allow for greater than one (1) hour of recording on both cameras. The first, and I believe most important is to make sure the supplied voltage does not drop significantly below six (6) volts. I know the specs indicate five (5) volts, but I've been unable to get the cameras to operate predictably below 6. The second , restrict the resolution to 1080. Both of these concerns, voltage and resolution, have been mentioned above and for me addressing both together have provided stable operation on the bench. I hope to fly them this weekend to test in-flight operability.
 
Thanks for the responses @BryRocket, I didn't realise you could rotate the mobius mini camera lens that way! That's really helpful and something I'd not considered. I don't have a 3D printer so I won't be going down the custom sled path. My expectation is that I'll mount the board with standoffs on a G10 sled and affix the lens with double sided tape and maybe a epoxied "shelf" for it to rest against during boost.

@ChuckH, I'm fairly certain the RunCam Split 3 starts writing out to microSD pretty much immediately after power on. These units are FPV devices with the added feature of writing out high def video onboard. They seem to be the "top models" in their respective product lines for lack of a better descriptor. But at their heart they're still FPV cams. Thinking about that use case I'd expect most flyers power on their FPV units, confirm they're working, and then start flying. I don't think they'd want to have to execute a process to make the camera start recording. Power on and off you go. At least that's how it "seems" to work in the few youtube videos i've looked at regarding them.

@Bruce, I'm not sure. You can get them on Ali and Banggood as well, but that's out of China. TBH though I suspect no matter where you purchase them they would have been made in China.
you can buy extension cables fot the mobius camera head end. https://www.ebay.com.au/itm/321175360075
 
I’ll observe this discussion as I’m real interested in going this route in the future so I can have a little more flexibility with battery capacity and mounting. I don’t have any experience with split camera systems though and haven’t researched it enough yet. I’ve always used “packaged” cameras and then use an extension cord for the lens module. Here is my most recent design. It allows the lens module to move in and out so the eBay can be slid into the rocket and then the lens extended outward in the airframe.
Although I have gleaned a lot from this thread, I would love to know more about how you got the lens flush with the outside of the switch band. It seems like you utilized some kind of spring from what I can tell, and as you slide the sled into the coupler, I'm assuming it just kind of grazes along the inside until it pops out of the lens hole in the coupler. Is this the idea, or is there some other, more sophisticated way that Im not seeing?
 
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