Leaving P4 Props on? Bad or fine?

Do you leave props on most of the time?

  • Yes

    Votes: 9 29.0%
  • No

    Votes: 22 71.0%

  • Total voters
    31
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Im pretty sure this is a stupid question. I read somewhere that leaving the props on is bad? It somehow warps the spring? So I decided to come on here and ask if any on you guys heard this or know anything about this. Do you take them off or leave them on?
 
I take mine off, because it is easier to handle in the house, and less likely to get snagged and knocked off a table, while charging the mounted externals. The props kind of get in the way. The easy on/off props are one of the best features of the P4, compared to the P3P. I always leave my P3P props attached so as not to strip the nylon theads.
 
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Either this forum or the other P4 forum you will find people commenting on shorten spring life due to frequent removal. We leave them on until we have have to remove them. In addition spare springs are part of our back up parts.
 
Last edited:
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Mine go on and off every flight . . (case stored) . . but it also forces me to inspect the blades EVERY time . .and I have often found bug debris needed cleaning under the blades even though they looked fine from the top. I also check the springs then too and have not found any issues with "fatigue" or "deformation" as a result . .in roughly 200 flights. I did replace all four blades once early on (about flight 10) after one struck a corn stock on landing. . . no other issues in over 60hrs of flying.
 
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Either this forum or the other P4 forum you will find people commenting on shorten spring life due to frequent removal. We leave them on until we have have to remove them. In addition spare springs are part of our back up parts.
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.
 
I only leave them on if I am going for another flight that same day and not moving to another location. I always store my equipment in it's case props off. The spring clips are not true spring steel they look like stainless steel and their elastic limit is surpassed and they will eventually stay lower than the original wich are 4mm, 5/32 inche. It realy does not matter if you take them off or not the damage is all ready done when you put your props on. As soon as the elastic limit is passed it will not come back to the original location. I place my finger nail under the tip and lift just until it touches under the plastic clip and they spring back to original height. The more you do this the weeker the metal will become, so I do not do this every flight, maybe 20 or so. I have over 200 flights and they still look good and check them in my preflight and I plan to change them at least once a year or if I damage them. They are not expensive and I already have my spare set in my case.
 
I only leave them on if I am going for another flight that same day and not moving to another location. I always store my equipment in it's case props off. The spring clips are not true spring steel they look like stainless steel and their elastic limit is surpassed and they will eventually stay lower than the original wich are 4mm, 5/32 inche. It realy does not matter if you take them off or not the damage is all ready done when you put your props on. As soon as the elastic limit is passed it will not come back to the original location. I place my finger nail under the tip and lift just until it touches under the plastic clip and they spring back to original height. The more you do this the weeker the metal will become, so I do not do this every flight, maybe 20 or so. I have over 200 flights and they still look good and check them in my preflight and I plan to change them at least once a year or if I damage them. They are not expensive and I already have my spare set in my case.

Do they just screw on and off the motor?



Sent from my iPad using PhantomPilots
 
They are under the plastic prop locks and sit directly on the motor. The 3 screws go thru the plastic prop locks and the spring clips and thread into the motor. Very very low torque on the screws, some time ago a fellow pilot had the torque specs posted. ( I sould have writen them on my spare clips! dang)
 
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It really does not matter if you take them off or not the damage is all ready done when you put your props on. As soon as the elastic limit is passed it will not come back to the original location.
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.:cool:
 
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.:cool:
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.
 
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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.
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?
 
I think the major damage is pressing them on because you have to go farther down in order for them to lock. And yes Guy I also think that this metal has memory when bent and not being true spring steel keeping them on may make things worse. I take my props off and I recommend not to straigthen the sping clips after every flight, the more often you flex them past the yied point the weeker they become. I think a test would be nice but it would be so long term! When I change my clips and if I remember I will mount a used set and keep a set of props on one pair and on and off the other pair for a few months and see what commes out of it. I will try to make it a school project and let the students evaluate it. Of course their repport will be in french but this could be interesting. I just changed my mind I will order a set of new clips and splurge six buck and will start the testing with all new clips as soon as they come in. These clips keep on props on and I think it's worth the effort and we should have some data before the years end.
 
I think the major damage is pressing them on because you have to go farther down in order for them to lock. And yes Guy I also think that this metal has memory when bent and not being true spring steel keeping them on may make things worse. I take my props off and I recommend not to straigthen the sping clips after every flight, the more often you flex them past the yied point the weeker they become. I think a test would be nice but it would be so long term! When I change my clips and if I remember I will mount a used set and keep a set of props on one pair and on and off the other pair for a few months and see what commes out of it. I will try to make it a school project and let the students evaluate it. Of course their repport will be in french but this could be interesting. I just changed my mind I will order a set of new clips and splurge six buck and will start the testing with all new clips as soon as they come in. These clips keep on props on and I think it's worth the effort and we should have some data before the years end.
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.
 
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.
 
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.
I just leave the battery in, unlocked, slightly out...
 
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.
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?

When removing your props, check for stress cracks, too! :eek:
 
Do your props wiggle a little when they are attached? Mine have a small amount of play in them. It concerns me for flight
 

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