Hi all,

Just a friendly reminder to give your prop mounts a check once in a while.  Even though my new P4P has only seen about 2 hours total flight time, I checked the prop mounts and three of the four could be wiggled on top of the motors... one of the mounts was surprisingly loose.  I was a bit shocked that three of the prop mounts were loose on the motors.

So, give them a check wouldya?

Matt

My P4P has 32 hours flight and I changed the prop mounts twice with new ones and one time propellers (and of course I balanced the propellers).

MaxP4 Posted at 2017-9-6 06:24
My P4P has 32 hours flight and I changed the prop mounts twice with new ones and one time propellers (and of course I balanced the propellers).

Max, did you replace the mounts with DJI parts or did you change over to the third-party metal mounts?

Are there any vids on how to do this?  

Also discovered fore some time ago that the screws were loose on both my Mavic and P4A. I unscrewed the screws and given them blue LOCTITE. After that, I have not noticed that the screws have been loosened again.

Regards Leif.

Jeez I'm gonna go check mine right now!

Can anyone confirm the screwdriver/hex key size needed for this?

I've tried 1mm and 2mm and neither fit!

jonnyrich Posted at 2017-9-6 15:09
Can anyone confirm the screwdriver/hex key size needed for this?

I've tried 1mm and 2mm and neither fit!

1.5mm !

And you shouldn't use Loctite, possibly it may damage the strength of the plastic and is totally unnecessary.

Draw a line with a permanent marker across the screws onto the mount so that you can do a quick visual check that they are not undoing again, tighten them enough so that they don't undo but not much more.

Thanks. Just checked mine. Also, I would not install 3rd party parts if your bird is under warranty. It would be a perfect excuse for DJI to void the warranty. I had my warranty voided because I glued the shell cracks. I should have just sent it in for repairs under warranty immediately. Lesson learned.I must say they only charged $70 for a shell replacement, so it wasn't a total ripoff. BTW it was my P3A, and I am happy with my DJI products so far.

Nigel_ Posted at 2017-9-6 15:30
1.5mm !

And you shouldn't use Loctite, possibly it may damage the strength of the plastic and is totally unnecessary.

When I replaced the motor mount screws on my P3A they had blue Loctite on them from the factory.

m1shootr Posted at 2017-9-7 07:59
When I replaced the motor mount screws on my P3A they had blue Loctite on them from the factory.

Correction: They had an unknown blue substance on them.

Should they be completely snug against the motor? Mine wiggle just a tiny bit.  They were like that when I unboxed it brand new.

It's a good habit to do a fully pre-flight checklist.

For any issue appears in warranty period, I would recommend you to send it in for warranty claim.

E.T._Drone_Home Posted at 2017-9-7 18:44
Should they be completely snug against the motor? Mine wiggle just a tiny bit.  They were like that when I unboxed it brand new.

Yes, they should be completely snug, but there were quite a lot of early P4P ones that where a little loose.  As long as the screws are not unscrewing then it is safe, I wouldn't bother sending it in for that, maybe plan to replace the props and prop mounts on it's annual service just in case the movement is causing wear with use.

Use thread lock on the bolts

had no idea this was a thing. will check tonight.thanks for headsup!

Mabou2 Posted at 2017-9-6 06:40
Max, did you replace the mounts with DJI parts or did you change over to the third-party metal mounts?

Yes, only original parts.

I like the metal mounts but i'm afraid that transmit to much heat to propellers.

Its always good to check, your props and battery before flight just as a pre check, you dont want to get high up and something happens.

One suggestion just hover it low to the ground and make sure all your controls and everything works.

BagoDJIoperator Posted at 2017-9-8 07:05
Its always good to check, your props and battery before flight just as a pre check, you dont want to get high up and something happens.

One suggestion just hover it low to the ground and make sure all your controls and everything works.

An excellent technique and one I use.  For most aircraft you can perform a control check while on the ground altitude and airspeed zero and hopefully you catch problems before takeoff.
However, here you have to get airborne first, so doing a low hover and then checking all control parameters before beginning the flight is more than just a good idea.  

Does anyone have an idea of how long the current plastic mounts will last?  I've seen post about some mount posts failing, but no insight in to how long they had them or how much use &/or abuse they suffered before failure.

Nigel_ Posted at 2017-9-6 15:30
1.5mm !

And you shouldn't use Loctite, possibly it may damage the strength of the plastic and is totally unnecessary.

Thanks!
Good advice

Nigel_ Posted at 2017-9-7 10:17
Correction: They had an unknown blue substance on them.

Yes, but whatever it is it is on there for a reason. I doubt if the substance is on there for cosmetic purposes. Perhaps a moderator can expound upon this.

m1shootr Posted at 2017-9-9 03:23
Yes, but whatever it is it is on there for a reason. I doubt if the substance is on there for cosmetic purposes. Perhaps a moderator can expound upon this.

My guess is that it is there to avoid potential problems when the screws are incorrectly tightened since the assembly staff at the factory can't be trusted 100%. If they come loose it seems they can fully unscrew before the end of the flight resulting in disaster, with the blue stuff if they come loose then the pilot will probably notice that the props are loose before they fall off since it will take several flights.

It may be some form of Loctite, but most Loctite products are known to weaken to some plastics so should not be used.  If you knew which Loctite product to use then you could use it, however it is not necessary if the screws are correctly tightened - not too tight and not too loose.

If you really want to use it then the correct thing to do would be to buy a new set of mounts that will come with screws with the correct blue stuff already applied.  You should still tighten the screws to the correct torque though and it is still wise to draw a line across them so that it is easy to check that they are not undoing.

The blue stuff is a goo to help keep the screws from loosening.  It isn't a thread lock, it just offers resistance to keep screws from easily spinning.

Nigel_ Posted at 2017-9-6 15:30
1.5mm !

And you shouldn't use Loctite, possibly it may damage the strength of the plastic and is totally unnecessary.

Maybe Nigel has misunderstood the use of Loctite ?  Do not lubricate the plastic but only the screw thread.

Regards Leif.

Nigel_ Posted at 2017-9-6 15:30
1.5mm !

And you shouldn't use Loctite, possibly it may damage the strength of the plastic and is totally unnecessary.

Thanks for the info about not using loctite. Another set of tools to have on hand also.

DJI Susan Posted at 2017-9-8 01:03
It's a good habit to do a fully pre-flight checklist.

For any issue appears in warranty period, I would recommend you to send it in for warranty claim.

Is there a torque values list for all the screws ? Snug and tight are different for each person.

SamDrucker Posted at 2017-9-18 15:08
Is there a torque values list for all the screws ? Snug and tight are different for each person.

Good question, I think for an aircraft there should be, but I've never seen one.

You don't want them too loose or too tight, both can result in failure.  Without a list of correct torque values the best option is to tighten them only enough that they don't unscrew themselves in use and then check them frequently.

This P4 system of connection between props and motors has always bothered me, for some reason.
It seems like a system that could easily fail.
I actually like the self tightening props of the Phantom 3, and trust them to stay intact once they are firmly snugged down on the motor shaft...


RedHotPoker

SamDrucker Posted at 2017-9-18 15:08
Is there a torque values list for all the screws ? Snug and tight are different for each person.

Sorry, there is no torque value for reference now.