The Hobbyking FPV250 multirotor frame is a very popular frame. Because it is light, strong and cheap. Currently this frame comes in 3 flavors.
HK FPV 250 basic quad frame
This is the basic and original model of this frame. Allthough it was originale designed as an FPV capable frame I advice not to use it as an FPV frame unless your motor and props are high quality and 100% balanced. It's small, light and ideal for flying in your backyard or a nearby park.
HK FPV 250L long quad frame
The long frame model was made to provide FPV users more space to mount there FPV camera, transmitter and even a second HD camera for recording. But you still need HQ, well balanced props and motors if you don't want to have that jello effect on your fpv cameras. The downside of this extension is that you can only mount 5 inch props, whereas 6 inch props could be mounted on the original frame wich makes the basic frame much more efficient.
HK FPV 250LH low hung quad frame
The 3e frame that HK released takes the benifites of the 2 previous frames. The long extension provides lots of room to mount all FPV gear and because it mounted on the bottom you can still mount 6 inch props making this an efficient frame. The extension is also attached to the frame by rubbers. HK calls this Clean-and-Dirty Kit. This should prevent jello effect cuased by vibration of motors and props.
In this blog I will investigate the vibration issue caused by motors and props. I'll compare the basic frame with the low hung frame with live telemetry output from the flight control board.