Simple, Effective MOds for the Sailfly-x and Red Devil

The good and bad of the Sailfly-X and Red Devil
Happymodel have launched two of the better value toothpicks recently of which I have reviewed both - the Happymodel Sailfly and the Eachine Red Devil. Unfortunately both have minor niggles on the FPV side of things -

• The Happymodel Sailfly-x is low on vtx power (25mw only) and the although good for an AIO camera/vtx it it has comparatively poor dynamic range. Also, you need to change canopy if you want to change camera angle

• The Eachine Red Devil (made by Happymodel) has a better VTX which goes up to 200mW, a better camera in the Caddx EOS2 but the canopy is plagued by Jello and the camera is terrible at handling the image in low light conditions with peculiar red hues showing up at odd times.

The objective of the mods:
Since the underlying powertrain of these quads is light and effective I set out to improve the above issues while trying to stay as light as possible. Also, in order to keep things simple I wanted to avoid soldering where possible to provide an easy and cost effective upgrade path for those who wanted to emulate the build. The result? I'm super pleased:

Modded version weighs just under 39g

Sailfly-x minus 3d printed battery holder (plus rubber band) is just over 38g

Eachine Red Devil is closer to 39g with battery holder

LArva-x is quite a bit heavier due to slightly bigger motors, heavier frame and dvr on board

Total specs on the above build are:

• Runcam Nano 2 4:3 with superior light handling
• Similar weight the Sailfly-X and Eachine Red Devil - very light in the world of toothpicks
• Ability to use any battery shape, not just those that fit the 3d printed mount

• Smart Audio vtx with up to 200mw
• Stronger canopy with quick adjustable angle camera mount
• 100% plug and play - no soldering required.

My start point was the Eachine Red Devil here. You can start with the Sailfly-x but you'll need the Red Devil Frame here which is about $6. This will allow you to flip the board with USB down so you can use the canopy.

Full list of parts used:

Runcam Nano 2  CMOS 2.1mm Lens Camera Special Design Version for Larva X. Make sure you get this one - it has the correct connector.

Happymodel Larva X Spare Part Frame Canopy Camera Mount. This is my dream canopy - cheap, light, compact, strong and adjustable camera angle 😍

Happymodel Larva X Spare Part M2x18 M2x20 M2 Screw Nut D4 Damping Ball. Needed for the longer steel screws to securely mount the canopy.

​Nano 5.8Ghz 25/100/200mW 40CH 3.3~5.5V VTX (you only need this if you are starting with the sailfly-x

Optional extras:

200 PCS 20mm Diameter Rubber Band Battery Fixed for UR65 UK65 Snapper6/7 Mobula7. Good sized rubber band for anything with a whoop sized boards. Really tough too - haven't broken a single one yet.

5 Pairs HQ Prop Durable T65MM 65mm 2.5 Inch 2-Blade Propeller for Ultramicro / Toothpick. Best prop for 65mm right now. These apparently have slightly less balance issues than the regular HQ 65mm

Gaoneng 7.6V 300mAh 80C/160C 2S HV 4.35V XT30 Lipo Battery. My favourite little 2s for these quads. 3-4 minutes flight

Gaoneng GNB 11.4V 300mAh 80C 3S XT30 Plug Lipo Battery. Same battery but 3s. Recommend you run a 80% throttle cut with 3s. Very fast!!

The Build.
The build is very straightforward, especially if you are coming from an Eachine Red Devil. I have however included the steps unique to the Sailfly-x in italics:
1. Change components to the Eachine Red Devil Frame
2. Remove canopy and unplug camera
3. Replace AIO camera from Sailfly-x with the Red Devil Nano VTX listed above
4. Replace 4x nylon screws for mounting crazybee board and canopy with the steel ones from the larva-x listed above
5. Mount the Runcam Nano 2 camera to the Larva-x canopy.

Mounting a Caddx EOS2 or Runcam Nano 2 is very easy with this canopy

6. Plug the Runcam Nano 2 camera into the nano-vtx

I had to change from connector on the Runcam Nano 2 but you can avoid this but purchasing the version I linked above

7. Install the canopy and secure with nylon m2 nuts
8. Loop the rubber bands over the end of the m2 screws on the side of the canopy as below.

The outcome
Super pleased with the outcome. Firstly all jello related to the awful red devil/trashcan canopy is gone. I love the larva-x canopy - it is strong yet lighter than any TPU canopy due to injection moulding. It is also super compact and has and excellent range for camera angle adjustment.

The camera is not a million miles better than the EOS2 in direct sunshine but it really comes into its own in low or less than perfect lighting conditions. The flight below was a late dusk and I has no issue with colour aberations or missing obstacles. The VTX from the Red Devil has proved sound as well - I like to run it on 100mW so as not to stress it.

Rubber bands are a much more practical mounting solution meaning I can quickly switch between mounting types. Anything with a battery less than about 35g should be using rubber bands.

HQ props are excellent. Personally I've had no issues with the regular 65mm but I hear some batches have had problems with balance whereas the t65mm have not. Also the t65mm cost slightly less and have the option for using screws if needed although I prefer no to on these motors.

Conclusion and recommendation
If you have a Eachine I'd definitely recommend upgrading to the canopy at minimum plus using rubber bands to mount your battery. From there the camera is a bit more expensive and perhaps not necessary but worth thinking about especially if you fly in less than perfect light.

For the Sailfly-x the decision is hard due to the extra parts needed - frame and vtx. Personally I'll be keeping my sailfly stock but if I only had that then the power bump from vtx and image bump from the better cam is well worth pondering as is the ability to adjust camera angle.

​Thanks for reading, if you found this article useful please feel free to like or share, the facebook links below directly link/like this article. Links are affiliated and help me buy the bits I need to produce this type of content. If you are looking for quads or parts check out my coupons and discounts page which I keep updated with only the parts and quads I like at a proper discount.