Review: Beta85X 4K Tiny Whoop Micro Quad

by Oscar

BetaFPV took the popular Beta85X, replaced the Turtle camera with the Caddx Tarsier and made the latest Beta85X 4K which is capable of recording up to 4K videos. It’s also now 4S compatible!

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I previously reviewed the Beta85X HD with the Turtle camera.

Where to Buy?

In the box there are the quad itself, a remote control and ND8 filter for the Tarsier camera. Manual is online.

Components and Specs

Here is the specification of the Beta85X 4K with comparison to the previous Beta85X HD.

Beta85X HD Beta85X 4K
FC F4 FC with MPU6000 F4 FC with MPU6000
ESC BLHeli_32 16A BLHeli_32 16A
Motor 1105 6000KV 1105 5000KV
Propellers 2″ 4-Blade 2″ 4-Blade
Battery 3S 4S
Camera CADDX Turtle V2 CADDX Tarsier
Receiver Frsky XM+ Frsky XM+
VTX Z02 (48ch,25/200mW) A01 (48ch,25/200mW)
Weight 75g 89g

We don’t see a massive difference from the previous Beta85X HD. The main change is the motor KV which has been dropped from 6000KV to 5000KV.

Another change is 4S support for the Beta85X 4K. This used to be a problem in the previous version, as some people had burnt ESC’s running 4S. It appears they have fixed this problem in the latest 4K version.

One reason that they recommend 4S on this quad is due to the increased weight. With the Tarsier 4K camera, and the canopy changes to accommodate the new camera, have increased the total weight by 14 grams.

What’s Special about the Beta85X 4K Whoop?

First thing I noticed is how expensive the new 4K whoop is. It retails for $260 (with radio receiver), which is $60 more than the HD version with the Turtle.

And it’s now getting heavier as well, weighing at 89g without battery, and I am not sure if you can still consider this a tiny whoop. I guess that’s why they now recommend 4S over 3S to compensate for the extra weight. But a 4S battery is also heavier, so that becomes a vicious circle.

The good news is, even with the recommended 4S 450mAh LiPo, it takes the total weight to around 140g, which is still way under the 250g weight limit to be able to fly without license in many countries.

Buy 4S 450mAh LiPo:

Side by side comparison with the Beta75X

The FC and ESC are NOT connected with rigid header pins anymore – it wasn’t a very good idea as it can break from crashes. They are now connected with flexible ribbon cable.

All the electronics: VTX, FC, ESC and camera are now plug and play, it’s solder-free when you have to repair or replace these parts.

The Tasier camera is mounted inside the canopy, and it’s separated from the FC stack. The camera is located much more forward than the previous version, which is a good thing as you can now angle the camera down and still not getting the props in view.

It has a carbon fibre bottom plate with arms where the motors are mounted on. This design increases the rigidity of the frame and help to reduce oscillations.

The battery connector is a XT30, with a 220uF capacitor solder to it and wrapped in heatshrink.

The camera and VTX can get really hot, do not hold the quad by the canopy, the exposed VTX can burn your fingers.

Overall the component and build quality are top notch.

How to Setup

There isn’t much info on how to setup this thing, so I will try to document what I did and you don’t have to repeat my mistakes.

Quad Setup

  • The Beta85X 4K Whoop comes with Betaflight Firmware 3.5.7. You could update it to the latest firmware, I didn’t and it worked just fine
  • Bind the XM+ receiver to the Taranis. Note that USB doesn’t power up RX, you must plug in LiPo
  • In Betaflight, I turn off RX_LOST Beacon and set Beacon Tone to 3
  • Setup modes for arm, angle mode and beeper
  • I have to turn off LED (in features) because it’s a bit too bright for me to fly indoor :)

That’s all you have to do to fly the quad, the rest of the setup is to get the Tarsier camera working.

Camera Setup

First of all, get a good SD card that supports 4K recording, ideally one with relatively large capacity because 4K videos take up a lot of space.

Here are my SD card recommendations.

Download the “CaddxFPV” app on your phone (there are multiple apps from Caddx, make sure it’s the right one).

There are two buttons to the camera located on the rear right of the quad. The button closer to the front of the quad toggles recording on and off. The red LED flashes when recording. Auto recording is on by default, which means as soon as you power up the quad, it will start recording.

To enable WiFi, hold down the record button for several seconds until the green LED flashes (on the left side of the quad) .

Go to your phone and find the WiFi network named “Caddx_XXXXX” (X being numbers). WiFi Password is 12345678.

Now open the App you downloaded on your phone. It’s similar to what the Runcam App can do, you can format the SD card inside the camera, change settings as well as playing back clips.

As your first time, I suggest formatting the SD card inside the camera. To do this, click on the gear icon on the top right, then Device Settings, and SD Format. This will delete everything on the SD Card so make sure you don’t have anything important on it.

Flight performance

The first problem I encountered was poor range. I couldn’t fly more than 150m or nearer behind trees without failsafe.

By mounting the RX antennas 90 degree apart helped slightly, but still not ideal. I will try changing the antenna length next (default length is 23mm), but it could just be a defective receiver, because I’ve used a number of XM+ receiver in the past and never had this problem.

Flight performance is similar to the previous Beta85X HD, it still can’t handle dive very well and sometimes it gets wash-out (prop wash, wobbles and out of control). To avoid this you just have to not drop throttle too rapidly when the quad is leveled. if you want to dive, try to pitch forward to minimize prop wash.

Although I am powering the quad with 4S 450mAh, it still doesn’t feel powerful. It hovers at 42-45% throttle. Certainly not the best whoop to perform acro moves.

As you can see in the video, it handles the wind well (15MPH at the time). There are some oscillations and wobbles at times, not much you can do really, all tiny whoops do that when there are gusts. However it flies pretty smooth and stable in calm weather, especially indoor. Beware of the noise though, it’s 4S powered and it can surely draw some attention.

The Tarsier has similar HD image quality to the Runcam Split or Caddx Turtle, but in 4K. The main advantage is the better WDR FPV feed. Here is my review of the Caddx Tarsier. When flying outdoor in day light, using the ND8 filter definitely makes the footage smoother and removes some of the jello/oscillations. But the image becomes darker and dull, you can fix that with some editing and color grading.

Here are some demo footage of FPV, HD, with and without ND filter in 1080p:

Here is the raw 4K footage uploaded to Youtube:

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Rich Sugden M.D. 6th April 2020 - 5:37 pm

Thanks for your review .. solved many problems getting my 85X 4K going … Still have a problem in that it will only record video to the SD card in 4K … all other settings, like 1080 just give a black screen?? Any suggestions?

Damian 28th January 2020 - 8:26 pm

Hi Oscar,
I loose video whrn the 85x4k is about 2 metres away not 150m, i think its in pitmode(?) Do you know how to check or change the vtx settings?

Oscar 2nd February 2020 - 4:04 pm

Did you update Betaflight without updating VTXTable?
You can check in OSD menu what mode the VTX is in and change it: