ricci2
Captain
Flight distance : 61158 ft
France
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Hello Chaps, and welcome Doghunter,
Great suggestion Doghunter, Non Newtonian viscoelastic sheer thickening fluid (Non-thixotropic) offers some great abilities in the world of dynamic damping but tuning the stuff is very precise, so you need to know the frequencies; however there is a fundamental downside, the properties of the substance cause the material to stiffen with shock loading, thus becoming less absorbent and better capable of transferring the load, also the rate of change is logarithmic. "blu tack" has all the properties of the above however when it is subject to external forces the damping rate will change and become like a reversed shock absorber so it will only be usable as a non dynamic absorber or sticky mass, its non-Newtonian aspects will not be usable, which is why Lt's very dense lead on adhesive pads work so well.
I do see a use for Non Newtonian properties within the drone business but haven't sorted how to implement them yet, input welcome as this is a power free resource that changes state with force input.
The cure for the Rolling shutter/jello is not complex but will require some disassembly and relocating of the gimbal support. I have taken some pictures for people to follow.
I will also do a video comparison to justify the mods and you could do one mod at a time to see if it alone is the fix or a combination of the two fixing it.The first thing to understand is the variable nature of each craft so what we are looking to do is blanket cover any area that propagates vibration to the cmos sensor.
The discovery that the top plate is a vibration amplifier should be the first place we look at. We are trying to stop it resonating with the simplest of measures. LT, adhesive lead pads will do the job but so will sticky felt pads, I use ones to put on chair feet, covered the carbon plate but left spaces between pads to decouple any low frequency transmissions. Like the old fashioned wall of egg boxes to absorb multiple frequencies. The important factor is to stop the carbon plate from ringing, it should be a dull thud. If you just do this damping then have a flight, it could be the only task you require. Another fix would be to change the material of the plate for something thicker and more dense, or pepper pot it with large holes.
If you need to go to the next step you have to remove all the camera attachment gear including the rubber dampers, and angled standoff arms and cable connectors so be gentle. You have to swap the left and right rear arms to face the opposite direction on the right & left side, same for the front ones too. This reversing allows you to get the gimbal connector in the middle of the craft where you can fine tune its location.
You are looking to align the pitch gimbal motor to the centre of the airframe and get the COG running through the cameras COG. This is only possible in the X, direction as viewed from the side. Note the X5R will be heavier and might have a cog different to the X5 so do your best to locate the cameras cog and get it inline with the airframes Y, axis centre as viewed from the side. I could not physically move the gimbal plate back enough to get it to the centre without reversing the arms, so don't compromise here just undo the eight hex heads on the arms and remembering to use loctite 222 or similar on the threads.
Moving the camera back will mean you can see the props if you pitch above the horizon by a few degrees or accelerate 100% and that could be a compromise you might have to except.
Why did DJI not mount the camera there in the first place? Why is this going to help with reducing rolling shutter/jello? Because the airframe is a rotating mass with six potential vibration creating machines on the periphery, the place to be is equal distance from where all the sources meet and potentially nullify one another. I am sure this is a great factor in reducing the dynamic movement of the camera when manoeuvring, especially when the camera is pointing to the ground. You must take in mind that when the camera is pointing down it offers the greatest air resistance due to its profile so with this knowledge high speed pictures or video shooting will have high dynamic force issues fighting the gimbal motors which are constantly stabilising the platform so consider much slower track speed if this is an issue.
I have some before and after footage I will upload to show you the results I have, and any questions You might have please feel free to fire them at me.
Happy wobble free flying.
I cant take credit for the fix if it works, so LT who spends hours testing new things is an equal partner and in fact started the entire thread.
Ricci
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