Unless I misunderstand, your first statement makes no sense. The spring life should be shortened by leaving them on all the time, not by frequent removal, as prop removal allows the spring to properly relax to its full tension in between uses. Please clarify.
Good advice and summary, but I am not sure I agree that that the damage is done when you put the props on. The real damage is from leaving the props on, which deforms the spring tension by not allowing it to relax back to its original state. The less time the spring is depressed, the longer the spring will maintain close to its original tension.
The type of metal used for the clips may relax under continuous bending from leaving the props on. Metals have a elastic zone that will regain it's original position when the load is released, is you pass this zone you enter the plastic zone (past the yield point) once this point is past the deformation will remain in the metal. When you torque a bolt you have to remain in the elastic zone wich is normaly calculated not to exceed 75% of it's yield point. The bolt will always hold it's clamping force when properly torqued, like the bolts holding your wheels on your car, they do not lose force with time. When you pass the yield point into the plastic the metal has no elasticity to pull and hold the objects together and lose their clamping ability. If you straigthen a piece of bent metal you can get it straight but it has lost most of it's strenght, so if you over torque a bolt, throw it away because it can't pull the parts together well any more. The torque applied to most bolts must be able to strech to bolt about .002 of a inche per inche of clamping lenght. Harder bolts require more torque to stretch but the lenght that the bolt streches remains almost the same. Most metals can only stretch about .002 per inche and stay in the elastic zone.Good advice and summary, but I am not sure I agree that that the damage is done when you put the props on. The real damage is from leaving the props on, which deforms the spring tension by not allowing it to relax back to its original state. The less time the spring is depressed, the longer the spring will maintain close to its original tension.
All good information again. So are you agreeing with me, that removal of the props after each flight minimizes the deformation, or, are you still suggesting that even putting on the props for flight only does just as much damage?
Looking forward to your testing results. It won't change what I do in terms of leaving them off except to fly, and also storing the battery outside the aircraft to keep its tension tight, but changing out the spring clips periodically might be worthwhile, depending upon your testing.
I also keep my battery out, I wish they would make a locking cover thats made like the battery to prevent any dust from getting inside the AC. I should contact my supplier to see if they would have any defective battery that they did not have to return to DJI. Safely remove the cells and use the shell as a dust cap.
Besides allowing prop inspection, removal also allows for easier handling for things like cleaning the UV filter and charging up permanently attached external batteries. During the UV filter cleaning yesterday was when I noticed stress cracks top and bottom around one P4 motor so severe that they nearly separated the arm end and motor from the shell! Could easily have snapped in two during the last flight! Some gaffers tape over the cracks and the top and bottom has reinforced the arm end, with a successful flight, but I am left wondering whether the weight of the externals caused these cracks, or if the extreme flying trying to chase down and follow boats going up to 200mph might have been the cause. Usually, I just fly straight ahead and not wildly back and forth at high speed. Anyone else seen P4 stress cracks top and bottom around a single motor, like on the P3?I leave mine on when I fly. Helps with the lift.
Seriously, I put on to fly, take off when I put it back in the case.
