3D FPV Tinywhoop

Have you ever wanted to fly FPV with 3D video (depth perception)? If you have a set of older skyzone goggles that have 3D FPV mode in the menus, and a spare VTX/Camera, you can try it out, super cheap and easy.

This simple lightweight TPU canopy just holds two FPV cameras at exactly the center of the ducts on a 65mm whoop frame and a spot to put a second VTX for sterescopic 3D FPV. Its designed to be used with a whoop FC that has a built in VTX (crazybee f4 lite, 2g4, betafpv matrix 5in1 etc), so you only need to add a single external VTX, and an extra camera to enjoy 3D FPV.

You will need to use an older Skyzone FPV goggle like the V2, Sky02 V3, Sky02s V+, Sky02x or Sky03. It does not work on the Sky02O, Sky02C, sky03O or Sky04 series onwards; basically anything that has a steadyview receiver dropped support of the 3D mode the older ones have. If in doubt, check the specs for your goggles, and go into the goggle menu (long press the right hand button "Track" to get into the menu and if it shows 3D in the second page you can use their 3D mode

How it works:

in 2015 or so Skyzone released a 3D FPV system which consisted of a big camera and VTX module with two big antennas on it. It works by sending the left and right video feed on 2 different video channels. The goggles separate the diversity receiver modules to receive the left video footage on one receiver, and the right footage on the other receiver. They dont tell you which channel goes to which eye, but with a bit of testing i found the default setup is R3 for left and R4 for the right eye. So this was all the rage for about a week but then everyone realised its big, expensive, and not very noticeable when you are flying fast outdoors. It works well for closer distances but you cant get too close to a quad with 5 inch props spinning at 30000rpm!

Then there were some noteable other options that made it smaller/lighter, and far more expensive: Blackbird V2 and Nerdcam3D. These worked on a single FPV channel, but they squashed left and right images into one frame (so you lose half of the already limited analog resolution).

So here is my attempt at making this much more accessible and fun. On a 20g tinywhoop, the effect is very noticeable, and its small enough to fly very close to people and things. And it can be done cheaply! If you already have a 65mm tinywhoop like a mobula6 or Air65 that has a built in VTX all you need to do is add an external VTX and a second camera. https://youtu.be/VqduSLmhwyI (looks like my right camera needs a clean...)

This 3D print holds 2 cameras precisely behindthe center of the front ducts of a tinywhoop. That equates to an IPD of about 46mm...a bit closer than human eyes but enough to have a 3D effect. Doing it centered on the ducts is intentional because the ducts are in your field of view, and i wanted them to line up in 3D mode. The Runcam Nano3 mount remixes the NANOMOUNT V2.5 which itself is a remix on Kbar's NanoStinky camera mount. The pinch mounts are based on Kbar's Little Stinker and McStinky canopies. For the mcstinky, i actually shrunk it down to be a tighter fit since i didnt want it slipping around. The 16x9 Ant version is for the special Ant Lite that was in the UZ85 and Flywoo sold it at one point. I dont know if many people had that version but i have two of them so i made a mount to suit them.

Building the 3D whoop:

I printed this with tree supports at a 65 degree angle... Which puts the camera mount horizontal (25 degree camera angle). But if you are comfortable with printing TPU it can probably be printed right way up as well.

The left camera connects to the FC as normal (Camera plug)

For the additional right camera, all we need is 5v and ground from the FC; this goes to the external VTX. The second camera's power, ground and video goes straight to the external VTX.

I am using the OVX300, but you might want to use a TBS Unify Nano or another VTX which is better suited to work WITHOUT SMART AUDIO. The FC cannot talk to the second VTX, as it is set to communicate with the builtin VTX (in my testing, if you assign the SmartAudio function to another UART the built in VTX goes to a random channel).

In my pics you see the SA wire soldered on. This is so i can update OpenVTX via passthrough flashing if i need to. I would need to change the port for SmartAudio to the UART i attached the green wire to (UART1), do the update then switch it back to the built in VTX (UART2) before flying.

The camera holder screws in to the side mounting posts on the Air65 frame. You may be able to use other frames, as long as the top of the mounting post is in line with the duct, as the camera mount sits on the duct and side braces For the nano3 and Ant Lite versions the screws are under where the camera sits, so once the mount is screwed in, put some kapton tape or electrical tape over the screw - it might short out components on the camera otherwise The cameras are press-fit into the housing, and should be quite secure. The second VTX is attached on its 'sled' with 3M VHB double sided tape The loops on the top of the camera mount are for feeding a 1.5mm carbon fiber rod through, to keep the cameras aligned (do this after everything else is built). It works without that, but you might have trouble focusing the 3D image if the cameras arent perfectly straight. 64mm of carbon rod weighs 0.15g so i think its worth it, but thats up to you. Just snip those 'ears' off if you arent using them.

Set the left camera/built in VTX to R3. Put your OSD in the corners, and keep it to a bare minimum if possible. Voltage and OSD at most (in the video above i have current draw on my OSD as well - i was testing motors and wanted to find the best combo for efficiency). The right camera has no OSD, so in your 3D image, you will get semi-transparent OSD. You dont want to be distracted by that...

Set the external VTX to R4. On Open VTX, you can set the channel with the button now. Cycle through all 48 channels until you are on R4, and set output power to 25mw (long press the button to change power - you want to be on power level 3 for 25mw).

In the pics i have an LHCP antenna on one side, which is matched on the goggles side, but in practice this doesnt really make much difference. If you have 2 linear antennas in a V configuration, do the same on the goggles.

My whoop configuration:

• Happymodel CrazybeeF4 Lite (from the original Mobula6)
• Happymodel S0702 23000kv (lowest kv, for efficiency)
• 2* Runcam Nano3
• Happymodel OVX300 OpenVTX VTX
• Tinywhoop TrueRC SMOL antenna LHCP
• Betafpv Air65 frame
• Gemfan 1219s propellers

The final weight is 20.37g. It is certainly not an ultralight and thats fine, it isnt a normal whoop. No weight saving measures done either; still got plugs on my motors and using metal screws. It would be trivial to get this under 20g, maybe just switching to the VCI lite motors or Betafpv 0702s