Simple, low cost cooling solution for Samsung Gear VR S6

After more than a year of my Samsung Galaxy S6 phone overheating after only about 10 minutes of play in my Innovator Edition Gear VR (SM-R321) headset, regardless of setting flight mode, wireless on/off, screen brightness, power saving, do-not-disturb mode, per these tips
https://www.vrheads.com/how-deal-gear-vr-overheating
https://www.reddit.com/r/GearVR/comments/3ybc9i/gear_vr_and_galaxy_s6_phone_overheating_messages/
https://forums.oculus.com/community/discussion/27568/consumer-vr-s6-heat-issue

I was losing enthusiasm and running out of $$$ to waste on the followup S7 & S8 and newer Gear VR headset.
I did get the latest Gear VR (SM-R324) headset + Touch Controller bundle for a reasonable price on ebay,
but I was still left with the problem of overheating, which apparently is especially bad on the Galaxy S6.
I was also quite dispirited in the wallet area upon learning that Google Daydream View would require a Google Pixel 2 or equivalent latest OLED phone (like the Samsung Galaxy S8).


I have read about numerous solutions specific to certain Gear VR models, and/or phone models, including clip-on fan mounts, heatsinks which required pulling the back cover and battery out of the phone, custom drilled or 3d-printed fan mounts and crazy looking aluminium foil heatsink rigs, and highly risky frozen coolant gel packs strapped to the phone (these people don't understand the concept of condensation occurring even outside a sealed cold gel pack, simply due to ambient humidity).
https://forums.oculus.com/community/discussion/32268/gear-vr-cooler-mod-guide
http://www.arvrmagazine.com/the-6freeze-galaxy-s6-air-cooling-system-for-gear-vr/
https://www.thingiverse.com/Kelvin820/collections/gearvr-cooling-solutions
https://www.reddit.com/r/GearVR/comments/3wgo5m/3_min_overheat_fix_attempt/
https://www.reddit.com/r/GearVR/comments/4wsulv/homemade_heatsink/

I decided the best & safest route was a very simple air-cooling solution with a fan small enough to fit just inside the gear vr faceplate, but not too small that airflow would be insignificant & ineffective. 
Being powered by the same usb connector as the gear VR itself would be nice but I decided against attempting to pull apart the headset for fear of irreversible damage.

Instead, I used three cheap items to make this a battery pack free-swivel-around-play-till-you-drop solution,
which can also be a mains-powered play-without-moving-too-much solution.
I am most impressed with the fact not only does the new Gear VR Touch Controller work with the Galaxy S6,
there is also no hardware dependency on the Gear VR headset - it works just fine on my old Innovator Edition SM-R321 model.  

So, on top of the Samsung Gear VR + Galaxy S6 + Touch Controller + micro USB charger cable

I got the following items:
- standard USB-A male to female 1.8M cable
- 60x60X10mm 5V USB Cooler Fan
- dual port 1A + 2.1A power pack

For the mains powered option, I got a dual-port USB mains adapter with at least 2A output on each port.
The official Samsung USB 5V @ 2A mains adapter seems to be the only thing which actually puts the S6 into 'fast charging' mode.

I wanted this solution to be VERY simple & easy to mount/dismount the phone from the Gear VR headset, and to plug/unplug the power source.
I also wanted the power source to be mounted on the headset somehow but the lightest power packs were too low on the mAh rating, and the best power-per-buck  vs low weight tradeoff got me a 6600mAh pack which even at 216g was still a bit too heavy to consider strapping to the actual headset, especially if I wanted to avoid neck strain and/or lie back on a pillow or lounge.
Since the overheating on the Galaxy S6 occurs primarily just under the camera lens, I positioned the fan so it would hang down just below the lens protrusion with the S6 mounted, and swing back up over to rest on the top of the Gear VR when unmounting the S6.

I achieved this of course with the amazingly high tech adhesive technology of ..... (wait for it)

sticky tape.

And here's the result, giving endless VR playtime, no overheating, cool-to-the-touch even after one hr solid play (eyestrain prevented further testing).

You can see in the side-on shots, the spinning fan pushes itself away from the phone face, which is fine, since that allows the airflow to disperse across the phone backplate for more effective thermal displacement.



I will definitely be able to enjoy VR again now - although Gear VR does have that unfortunate degree-of-freedom limitation where physical motion-in-space of the headset and controller are not represented, as they are with both the Oculus Rift VR headset and new touch controllers... 
Also the CPU/GPU limit on phones doesn't allow the same level of detail you can generate with nVidia GTX high end cards.  
I only have a GTX 970 & Intel 3770K and they are perfectly adequate for Oculus Rift VR.