Building my first 5" freestyle quad with the SpeedyBee F405 V4 stack and planning to use DJI O4 Pro for video. The O4 Pro is considered the best digital FPV system for 5-inch builds in 2026 with excellent HD video quality and low latency. However, I'm concerned about mounting clearances and potential interference with the stack layout.

Has anyone successfully mounted the O4 air unit with this particular stack? Are there any specific frame recommendations that work well with this combination? Frame clearance and mounting patterns for flight controller and video transmitter compatibility are critical considerations.

Also wondering about power draw - will the F405 V4's 5V BEC handle the O4 power requirements without issues?

Used this exact combo on my latest build. The O4 fits perfectly on most modern 5" frames with proper 30.5mm mounting holes. Just make sure you have at least 15mm clearance above the FC stack for the air unit.

I had power issues initially - the O4 draws about 8W peak. Power chip damage can occur from voltage surges over 30V, so I added a dedicated 12V step-down module instead of relying on the FC's BEC. Much more stable now.

Frame selection is crucial here. The GEPRC Vapor D5/X5 offers excellent DJI O4 Pro compatibility with clean internal layout for straightforward wiring. Worth the extra cost for the hassle it saves during assembly.