KevDrones Posted at 2017-2-6 20:43
By the way what is a polar region, is it the North and South Pole?

Yes, GPS does not work at extreme latitudes. Compass problems too.

Very well put together information. Thank You. Wish I've found this info before I flew. But still flying after 15 hours, with only  broken props.

Thank you for trying to help. I for one appreciate the info....

Thanks for your share

I just got my phantom 4 and I'm having video issues during flight and playback any thoughts?
Please advise

tokenbrit Posted at 2017-1-16 15:03
"If you haven’t used a set of propellers for more than 50 flights, but they’re over a year old, still change them, as the threads will degrade over time from exposure to air."

Air does not deteriorate plastic, rather mousture and other contaminants can cause "hydrolysis", a chemical process that causes certain chemical bonds to break or "unzip" leading to their deterioration. In addition, UV light (from the sun's rays) also contributed to polymeric deterioration. To the extent that props are molded using thermoplastic alloys (as opposed to thermoset resins) exposure to heat may cause warpage.

I haven't studied how props are molded nor what polymers or alloys are used, but a good rule of thumb is if you know that plastic parts are prone to deteriorate in the presence of moisture, UV, or heat, is to store those parts in a cool, dark, and dry place when not in use. Keep fresh desiccant (moisture scavenging) bags with the items you store and wish to protect.

Since I'm new to the forum (but not to polymers) and this is my first post, I am happy to defer to the greater and sage wisdom of others (except about reading manuals. I never read manuals.)

Cheers!

Mike-the-cat Posted at 2017-2-6 16:42
Very good points but have you ever tried to write an instruction manual for a kid with a short attention span?

That describes many newbie flyers and customers.

ROFL made my day

Defiant_Child Posted at 2017-2-12 01:42
Air does not deteriorate plastic, rather mousture and other contaminants can cause "hydrolysis", a chemical process that causes certain chemical bonds to break or "unzip" leading to their deterioration. In addition, UV light (from the sun's rays) also contributed to polymeric deterioration. To the extent that props are molded using thermoplastic alloys (as opposed to thermoset resins) exposure to heat may cause warpage.

I haven't studied how props are molded nor what polymers or alloys are used, but a good rule of thumb is if you know that plastic parts are prone to deteriorate in the presence of moisture, UV, or heat, is to store those parts in a cool, dark, and dry place when not in use. Keep fresh desiccant (moisture scavenging) bags with the items you store and wish to protect.

Thanks - you obviously know your topic

tokenbrit Posted at 2017-1-16 15:03
"If you haven’t used a set of propellers for more than 50 flights, but they’re over a year old, still change them, as the threads will degrade over time from exposure to air."

P4 no thread on props.
Therefore not applicable.

All P4 and P4Ps have mechanical locking.

THANK YOU FOR POSTING.

Well I never even thought of changing the propellers unless they're damaged. Good to know. Thanks.

Great tips, excellent! I too was unsure about the RTH function, i have not tried it yet as always have LOS, safety first!

I also didn't know about the RTH 20mtr rule .....good to know as this could really catch a noob like me out :-)

nice tips to be known!

Good sharing. tq.

trance728- Posted at 2017-1-16 23:21
Sounds like a ploy to get you to buy more propellers.

If they are subject to air degradation, why are they not sealed when new? How are you supposed to know how old a set of propellers you purchased even are? It's not like they have dates printed on them.

DJI propellers are sealed when they are new.

SkyerUAS Posted at 2017-1-28 07:34
Quote -"We suggest changing propellers every 50 flights, and a set of propellers should not be used for more than 100 flights. If you haven’t used a set of propellers for more than 50 flights, but they’re over a year old, still change them, as the threads will degrade over time from exposure to air."-

I'd like to understand why the recomended prop replacement interval is based on flights instead of flight time. If the concern is the cumulative stress fatigue on the props, the wear rate would be paced  by the duration and intensity of the stress, which are linked to flight times and types of flight profiles/maneuvers (i.e. aggressive flying/braking vs. hovering or  smooth movements). Recognizing that operating conditions are many and varied, I suppose DJI may be using the average air  time per flight they see from the telemetry data that the DJI GO app collects, but given that it also records flight time, it seems it would be more appropriate to have a recommended interval based on flight time, with a plus/minus range based on mission profiles.

The only issue i see with props is they only "wear out" when being installed and removed after each flight. The threads get worn since were talking about plastic against a metal motor stud. Over time I can see the threads getting worn.

Kilted Flyer (D Posted at 2017-2-25 13:23
The only issue i see with props is they only "wear out" when being installed and removed after each flight. The threads get worn since were talking about plastic against a metal motor stud. Over time I can see the threads getting worn.

A valid point

SKYER
“Fly your drone as though you were flying in it yourself…”
See aerial short films at my YouTube Channel: https://www.youtube.com/channel/UC304REG4t2_OWJmQDHLvQ2w

Well written. Thanks for sharing.

phil0 Posted at 2017-2-16 05:50
Well I never even thought of changing the propellers unless they're damaged. Good to know. Thanks.

I've done over 130 flights on the same props and they are as good as new.  
Then again I don't use them to chop grass or leaves off trees.

I also do not remove them from my drone.  

All good points.
Will be saving this to brush up on down the road as an easy reminder!

Thank you for the advices, very helpful. I am newbe so I want to know as much as possible to fly safely.

Thanks

Hello Mindy - what's the logic behind making the drone land where it is when RTH Is pressed  within 20 meters of the home point please? Why not just make it return to the home point? I have never understood this.

Very nice summary of problem situations and thank you for sharing.

A good preflight check list and some common sense will take care of most of these.

Rich

Number 8 helps. Thanks1

Good info, thanks!

This is a great outline.

tokenbrit Posted at 2017-3-7 04:51
Hello Mindy - what's the logic behind making the drone land where it is when RTH Is pressed  within 20 meters of the home point please? Why not just make it return to the home point? I have never understood this.

It's probably a safety issue. DJI does not want the DJI firmware to take over flight if it's already that close to the take off point. I'd think they know usually the operator is close to that point. So it does not take over at all. However, once it's further away, it has no choice but to take over and fly back to the home point.

R&L Aerial  Posted at 2017-1-26 10:29
#8 would not be an issue if DJI would leave your RTH altitude alone when upgrading the app. I have RTH set at 50 meter because trees in my area are 30 meters tall. Every time I update the app it resets RTH altitude back to 30 meters and gives you no notification that RTH altitude has been reset.

They warn you the settings generally may change, so it is your responsibility to check.

Thanks; as a beginner, I need this.