You all know that I like to put action cameras on my RC vehicles to record first-person video footage. I've recently had a little trouble with that because of the low temperatures here in Buffalo. The cold was making my cameras shut down in the middle of a flight or drive. The good news is that I've found a simple and cheap DIY solution!
My current onboard camera of choice is the RunCam 2. I have two of them and a few extra batteries. All of this equipment gets used frequently. Until my recent experiences using the cameras in cold weather, I've found them to be quite reliable.
When operating my RunCam2s in freezing temperatures, their performance is unpredictable. Everything is usually fine if the camera is on a tripod of other static mount. But all bets are off once you strap it to something that moves it through the air. Unlike other action cameras, such as GoPro Heroes, the RunCam2 does not use a protective outer case. The camera body is directly exposed to the frigid atmosphere. Vent holes in the body also allow the cold air to reach the electronics within.
I suspected that the root cause of the problem was the camera's battery. LiPo cells just do not work very well when cold. In this case, the LiPo battery was getting so cold that it couldn't keep up with the camera's demands. I began placing microwavable heating pads in my camera bag to keep the batteries warm until right before I used them. While the cameras ran longer, they still shut down in flight.
I needed to find a way to seal the vent holes in the case and also provide some degree of thermal insulation. Whatever method I used would also have to be lightweight and low-profile. After exploring a few potential options, I decided to borrow a page from the cosplay handbook and use EVA foam.
If you're not familiar with EVA (Ethylene-Vinyl Acetate) foam, it is a squishy, closed-cell material that is usually sold in sheets. Cosplay costume makers use EVA foam in lots of creative ways. Still not sure what EVA foam is? Fine, it's the stuff that beer koozies are usually made of. Now are we on the same page?
I figured that the same thermal insulation properties that keep my beer cold would also keep my cameras warm. I guess you could say that I made camera koozies. I wasn't exactly sure what I would need, so I bought a few sheets of 2mm and 6mm EVA foam at my local craft store. Each sheet was only $1 and provided way more material than I needed.
This was my first time working with EVA foam. I spent a little time experimenting with different ways to cut and glue it. I decided that I prefer to use scissors on the 2mm foam and a sharp #11 X-Acto on the thicker stuff. Low-temp hot glue and Foam-Tac both work great to bond the foam together.
My prototype camera koozie was a perhaps a little over-engineered. I basically designed a box that would fit around the RunCam2 and its mounting cradle. The front, top, and sides were constructed of 6mm foam. I used 2mm foam for the bottom and back. The back piece is actually a flap that wraps around and attaches to the bottom with small squares of very thin Velcro. I just open up the back flap when I need to insert or remove the camera.
I wanted the power/shutter button of the camera to be accessible through the case. To accomplish this, I cut a hole in the top side of the case over the button. Then I lined the bottom of the hole with white 2mm foam. The thin white foam is translucent enough that I can usually see the indicator light built into the button. In hindsight, the bottom liner is probably overkill.
This EVA foam is lightweight stuff. My completed prototype weighs just 5.1 grams, which is insignificant for any of my applications with this camera. However, my decision to use 6mm foam resulted in a rather bulky profile. One of my favorite things about the RunCam2 is that it is relatively aerodynamic (as cameras go). This thick koozie increased he frontal area by about 75% and the side area by 45%. I decided that if the koozie kept the camera working in cold weather, the additional aerodynamic drag would be worth it.
I did not approach my testing in the most scientific manner, but I am confident in the results. I basically mounted my two cameras on opposite wingtips of the same RC airplane. One camera was bare, while the other had the koozie. I sent the airplane up numerous times on a 25-degree (F) day.
The bare camera did not shut itself off on every flight, but it did zonk on out several occasions. The insulated camera never shut down. These results were consistent no matter which camera was bare or insulated. My testing indicated that the koozie was keeping the camera sufficiently warm.
I decided that my follow-up camera koozie could be a bit svelter. The only 6mm foam is the front piece that surrounds the lens. The rest is a single piece of 2mm foam that wraps around the camera. I hot-glued the wrap to the front piece and then secured the ends of the wrap with an overlay of 2mm foam along the bottom seam.
As before, the rear panel is a flap that provides access to install or remove the camera. I originally used Velcro to secure the flap. But I now prefer to simply tuck the flaps in place. This camera koozie weighs just 2.2 grams and has a noticeably smaller footprint than my prototype.
My initial testing indicates that the thinner koozie is also effective at keeping the camera warm. On my most recent outing, I had both cameras insulated and neither of them ever shut down. At the risk of tempting fate, I think I can safely say that my cold-weather action-camera woes are behind me.
Do Your Thing
I think the process for making these camera insulators is intuitive enough that templates are unnecessary. The only real revelation to share is that EVA foam is a handy material to use for this task. How you go about using it to protect your particular camera is open to infinite interpretations. In fact, I just took a quick break from writing this article to whip up a simple 1-piece koozie that is secured with rubber bands.
If your action camera has been giving you fits in the cold, try wrapping it with some EVA foam. As always, we'd love for you to share your own ideas and results in the comments section.
Terry is a freelance writer living in Buffalo, NY. Visit his website at TerryDunn.org and follow him on Twitter and Facebook. You can also hear Terry talk about RC hobbies as one of the hosts of the RC Roundtable podcast.