At a $100 average retail price, the 85mm Emax Babyhawk is the first affordable micro brushless FPV quadcopter. It comes as plug-and-play, which requires a flight battery and, thanks to its F3 Femto Flight Controller, a receiver from a variety of capable protocols.
Emax Babyhawk Features
- AIO 800TVL CMOS Camera, 25mW VTX, Dipole Antenna
- Femto F3 FC w/Integrated PDB, SPRACING F3EVO Firmware
- Emax Bullet 6A BLHeli_S 2S Plug-in ESCs
- Emax 1104 5250Kv Brushless Motors
- 2.3″, 4.5″ Pitch, Bullnose Propellers
- Molded Polycarbonate Plastic Airframe
- Molded Polycarbonate Plastic Prop Guards
Flight Controller Remount
The factory installed double-sided foam tape under the flight controller on my Babyhawk did not stick well and was loose when received. I replaced it with two layers of 3M Scotch 30lb Extreme Mounting Tape. Since the original tape was still stuck to the airframe and not the FC, I increased the width of the tape to allow more adhesion to components on the FC. The photo below shows the original double-sided foam tape removed. Another factory flub: You can flip the ESCs over, remove tape backing and stick them to the airframe.
The Emax Babyhawk comes as plug-and-play (PNP), meaning it requires a receiver to operate. Just as I did with my HolyBro Shuriken 180 Pro, I went with the ultra-reliable Lemon Rx DSMX-Compatible Diversity Satellite Receiver with long antennas. I have had zero problems with Lemon Rx receivers and can’t say enough good things about them!
Receiver Case Removal
I removed the Lemon Rx Satellite Receiver from its plastic case and put clear Polyolefin heat-shrink tubing around it. The white material on one end is white vinyl electrical tape that I wrapped around the end before installing the heat-shrink tubing. This keeps the edge of receiver from making contact with the 3 pins on the flight controller.
With only 3 wires to solder, connecting the Lemon Rx Satellite Receiver was super easy. It requires 3.3V for power so I soldered the Positive lead to the FC boot pad in the corner, as opposed to the SBUS pins. I soldered Ground and Signal to the SBUS pins and put a piece of heat-shrink tubing over the unused 5V center pin. I used a satellite pigtail that I had instead of cutting down the original Lemon Rx Satellite cable. The Emax F3 Femto PDF has nice color diagram showing how to connect different receivers.
Other radio brands/protocols shown here: Emax Femto F3 FC with Integrated PDB
The most prevalent receiver mounting locations on the Emax Babyhawk are on back of the FPV camera housing, and in my case, directly on top of the FC. The Lemon Rx Satellite is fairly secure just sitting on top of the FC, under wires and in between the FPV camera stanchions. However, I can always add double-sided foam tape later on if needed.
Antenna Orientation and Mounting
Orientation of dual diversity antennas should be as close as possible to 90-degrees. There are a few options for diversity antenna placement on the Emax Babyhawk. They can be ran down two arms of the airframe or one down through to the bottom and one on top. I mounted the longer Lemon Rx antennas on top in white plastic tubes, which are from cotton swabs, and secured them with tie-wraps to plastic brackets attached to the camera housing screws. The screws are long enough to retain the original nylon locking nuts.
FC Configuration for Receiver
Steps I took to configure the Babyhawk Femto FC for the Lemon Rx Diversity Satellite Receiver:
- Install STM32 VCP Driver (Windows 7 Pro laptop). Launch Betaflight (Bf).
- Bf Ports: disable UART1 (MSP off), enable Serial RX (not MSP) on UART3, click Save and Reboot.
- Bf Configuration: set Receiver to Serial-based Receiver (SPEKSAT, SBUS, etc.), set Serial Receiver Provider to SPEKTRUM2048 (DX18 radio), click Save and Reboot.
- Bf CLI commands: “set spektrum_sat_bind=9” and “save” (auto-bind satellite).
- Physically bind transmitter and receiver.
- Bf CLI commands: “set spektrum_sat_bind=0” and “save” (removes auto-bind).
- Bf CLI command: “dump” then copy and paste into text file to save a backup.
- Set TX Channel Reversing and Travels. Example: Radio Setup for Shuriken 180 Pro
- Set Modes in Betaflight and TX. Example: Betaflight Setup for Shuriken 180 Pro
Battery Cushion Grip Pad
I try to repurpose things whenever possible. One thing that came in handy for this build was an old ball style mousepad with Closed Cell Neoprene Sponge Rubber backing, which is grippy and has just the right amount of cushion for the battery. I cut a section from the mousepad and glued it to the bottom of the airframe using Loctite Stik’n Seal Adhesive.
Update: Battery Strap Adhesive
Straps on good motocross goggles have beads of silicone glue on the inside to help keep the goggle in place on the helmet. I borrowed this feature for the Babyhawk battery strap to help keep the battery more secure. I supposed Silicone glue would have also worked here but I used Loctite Vinyl, Fabric & Plastic Transparent Flexible Adhesive because it flows out a little more (less viscous), making a thinner layer. I used 2 coats to create a nice soft rubber-like layer on the inside surface of the battery strap.
Emax recommends a 300mAh 2S LiPo battery for the Babyhawk. I absolutely love the Thunder Power 220mAh 1S FPV Adrenaline 50C Batteries for my Inductrix quads, Tiny Whoops and UMX aircraft so when deciding what battery to use for the Emax Babyhawk, the Thunder Power 325mAh 2S 7.4V Rampage 70C LiPo Battery was my first choice.
Thunder Power 325mAh 2S Rampage 70C LiPo Specs
- Max Charge: 12C or 3.9A
- Max Cont. Discharge: 70C or 22.75A
- Max Burst Discharge: 140C or 45.5A
- Weight: 23g Avg measured
- Dimensions: 11 x 25 x 45mm
- Connectors: JST-RCY Main, JST-XH Balance
Update: The Thunder Power 325mAh 2S Rampage 70C LiPo Batteries are turning out to be a GREAT little battery for the Babyhawk! They are light, almost no sag, and fly for a good 3 to 3.5 minutes of hard flying with flips and rolls while under the goggles.
Transmitter Setup and Betaflight Configuration
Transmitter setup and Betaflight configuration were similar to that of my HolyBro Shuriken 180 Pro except I have not yet updated the version of Betaflight that came pre-flashed on the Emax Babyhawk, which was 3.0.1. I will edit this page with any updates as I do them.
- Transmitter Setup for the Shuriken 180 Pro for Reference
- Betaflight Setup for the Shuriken 180 Pro for Reference
Emax Babyhawk Weights
- Babyhawk with props: 60g
- Babyhawk with props and guards: 68g
- Babyhawk with props, guards and Lemon Rx satellite: 72g
(Babyhawk flying weight minus battery: 72g)
- Babyhawk AUW with TP 325mAh 2S 70C LiPo Battery: 95g
Screw Head Sizes
The hex or allen head wrench or driver that fit best in the screws on my Babyhawk were 1.5mm or a well used 1/16″ for the larger headed screws (airframe and props) and a 1.3mm or 0.050″ for the motor/prop guards. Note: If you remove the prop guards for flight, make sure to use the shorter length screws so they do not protrude into the motor windings when tightened down.
Parts Used in Emax Babyhawk Build
- New: TacoRC Stretched-X CF Babyhawk Frame
- Lemon Rx DSMX-Compatible Diversity Satellite, LM0037
- Thunder Power 325mAh 2S Rampage 70C LiPo, TP325-2SR70J
Emax Babyhawk Videos
Further Help Setting Up Babyhawk
If you need further help with setting up an Emax Babyhawk, there are some decent videos on YouTube. Here are a few:
- The FT Gremlin uses the same basic electronics: How To Build a Gremlin
- PIDs, RX, beeper, other setup tips: Comprehensive Emax Babyhawk Video
- Betaflight related videos in RC How-to Videos: Betaflight Setup & Tuning
Close-ups, Feedback and Reviews
To be more mobile friendly, photos on TazRC are limited in size. I would be happy to post any close-up photos on request. Just leave a comment below. Also, feel free to leave your feedback or personal review on the Emax Babyhawk. Registration not required.
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