Thought I'd better share this as i've never seen anything come close in performance.
This is an FPV 250 in hover! On the left chart -- Less than 0.2g is good, 0.8 to 1.2 is excellent, but an average score of 0.01 is just nuts! I've seen numbers as low as this once before but the VDEP was dampened in a way that ship attitude variability (the right chart) suffered greatly (the VDEP was too isolated from the frame to be able to control it). Usually, with dampers, one trades lower vibration for ship control. Once the PIDs are tuned, the control numbers will improve even more.
The entire damper system weighs less than 12 grams. So little vibration is added lifting the dampers.
The design was purely a fluke. I was trying to solve a different problem and just wanted a slick and easy way to activate and deactivate a damper system.
This is how the damper is built. The damper is a 450000039-0 Vibration Damping Ball 50 gram found at Hobby King. The damper housing is 1-ply Carbon Skin 1/8" Balsa Core Sandwich Panel. The housing can be bonded with about anything. But bond the assembly to the motor mast with something good (e.g., 3M 2216). Getting adhesive (from squeeze out) on the exterior of the ball when assembling the housing is OK and actually good as it helps keep the ball inside the routed-to-fit housing when inserting the axle. The axle is a 0.155" (4 mm) extruded carbon tube. These dampers are good up to a VDEP weighing 200 - 600 grams or one damper per 50 -150 grams of VDEP. The FPV 250 had four dampers (2 on each axle).
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AHHH!!! The hole center is dampened from motors, battery included, that's give more weight mass to the FC and better vibes accuracy, that's correct?
yes .. the Frame only contains the rotors (esc, motors, props), masts, spars, and video transmitter/antenna where as the VDEP contains the Pixhawk, receiver, power module, battery, camera(s), gps/mag, axle, and cage ... with the frame and VDEP separated by the 4 balls.
Nice design :O
i was surprised by something else too. i didn't expect the ball to work on its side. the best you can expect from dampers like this are a 10x reduction in vibration (see earlier test data on many different types of dampers). When tested externally (not through the Pixhawk accelerometers but using an Extech Vibration Meter), there was a 10x reduction in vibration when the dampers were activated. so force relative to ball orientation didn't seem to matter.