Project 399 - Practice Rig - R4 Street CE

By Tombo on Feb 07, 2020

12  984  2

Project399 - Practice Rig - R4 Street Conversion

The R4 Street Practice Rig takes the already bullet proof Project 399 Practice Rig Frame, and retrofits it into a DRL Style Racer 4 Canopy. This modification requires only the 2 halfplates (3mm each), and 4 arms (6mm each). There is an example of the frame build on this site showing the configuration of the carbon. If you choose to take your existing practice rig and use it in this configuration, you will require the 3D printed pieces for assembly. Please note that there are a few options depending on the setup you are using. Select the appropriate Camera Cradle for the HD DJI AirUnit or Analog Camera System. The Analog camera has been tested to fit a RunCam Racer or Microswift. The bottom shell also has two options, a 5s 1800mah battery or 5s 2200mah battery. Currently 2200mah 5s batteries are available from various online FPV stores. The 2200mah bottom canopy was designed around the Pyrodrone 2200mah 5s pack. Since the Pyrodrone Pack is slightly larger than the RDQ or CNHL Battery, these should fit as well in the battery cavity.

Be sure to join the Facebook Group to learn more


Part List


The Practice Rig (5 builds)

Flight Controller

Hobbywing XRotor Micro 30x30Stack/Combo (F4 FC, 60A 4in1 ESC) (4 builds)


4 x Avenger 2510 Motor (4 builds)


HQ Prop Durable 7x4x3 Tri-Blade 7" Prop 4 Pack - Grey (9 builds)

FPV Camera

DJI Digital FPV Air Unit - Ultra Low Latency 720p 120FPS Digital HD (85 builds)


FrSky XM+ SBUS 2.4GHz Mini ReceiverDefault Title (1368 builds)


RDQ Series 18.5V 5S 2200mAh 80C Long Range LiPo Battery - XT60 (24 builds)

Misc Parts

8 x X-Class xLED (3 builds)

Misc Parts

2-12s LED PDB with FC Switch (2 builds)
Show stores (4)


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Knockout808   Feb 22, 2020  

I absolutely love this! Great work! Is there any chance you would share the DRL body STL files?

Tombo   Mar 07, 2020 

Check out the FB group link I provided, lots of info there as well on the build.

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