Propeller shelf life

[AlanTheBeast]

The guy at my DJI store told me to stay away from carbon fiber blades for my p3a. Can't remember why though.

Seems excessive to me - and possibly very dangerous.

 

[Monte55]

I started by assuming I'd get informed by the good people on this group. There are no stupid questions.

That is false. There are many stupid questions.

 

[AlanTheBeast]

That is false. There are many stupid questions.

Not at all. There are only stupid replies.

 

[Monte55]

Not at all. There are only stupid replies.

Yeah...from stupid people

 

[David Rodwell]

I would love to get 50 flights from a set of props.

My very first problem was my right ring finger followed by tree limbs, the sides of buildings, a concrete post and most recently, the tail light on my Volvo!

As far a strange translations...when we were kids buying firecrackers, the instructions read: "Light fuse...retire quickly".

 

[DEHANEY DESTINATIONS]

I was actually considering varnishing a set of blades one day and testing at a low altitude...or some other hardening coat that will not change the weight drastically...if this works I may coat the entire drone leaving only accessible areas uncoated...the idea is to kinda try armoring against accidents...

 

[Sky Boss]

I have hundreds of flights on my P for original propellers never had a problem.

 

[AlanTheBeast]

Thanks to all that replied. Nice to know I don't need to keep a frickin propeller log!

 

[Meta4]

I would love to get 50 flights from a set of props.
My very first problem was my right ring finger followed by tree limbs, the sides of buildings, a concrete post and most recently, the tail light on my Volvo!

Obstacles are the number one killer of Phantoms and obstacle avoidance isn't magic.
It has a number of limitations as described in the manual.
You need to have a fear of flying close to trees, buildings and other obstacles.
Get out in the open and your props will last for a very long time.

 

[Erised]

I been flying my P4 for almost a year now with over 250 flights and 4,000,000 feet and they still look like new. When compared to my new spare props the pitch looks identical.
If you nick them change them, if you don't fly them. If I cut bugs I clean them with dish soap and warm water and never use any type of chemical cleaner on my craft.
If you have seen the video when the guy cuts pieces of the prop off to show that it can fly with pieces missing, the guy has difficulty cutting them with side cutters, so I think there pretty tough.

 

[DefiantChild]

I was in the polymer business for 30 years. Back in the day, "glass" reinforced generally meant fiberglass fibers or particles of a certain density ratio were added to a polymer alloy or resin to enhance hardness, rigidity, and/or toughness. Today, extruders use anything from sintered buckey-balls, to ceramic powders, to exotic blends of "fillers".

Polymers are generally the weakest link depending on chemical structure. They all have varying degrees of susceptibility to moisture, oxidation, ultraviolet, and heat. Polymers fatigue over time. Flex introduces hysteresis which produces heat build ups accelerating deterioration.

It's really easy to over analyze, especially if you have to guess at the polymer composition, fillers, and manufacturing methods. In the end your mileage is going to vary. Some folks will see much longer life than others. Impact on trees, sides of buildings, and hillsides, oddly, shorten propeller life. We live in an imperfect world.

So if asked, my technical answer would be to "carry spares" and change whenever it "feels" right.

 

[AlanTheBeast]

I was in the polymer business for 30 years. Back in the day, "glass" reinforced generally meant fiberglass fibers or particles of a certain density ratio were added to a polymer alloy or resin to enhance hardness, rigidity, and/or toughness. Today, extruders use anything from sintered buckey-balls, to ceramic powders, to exotic blends of "fillers".

Polymers are generally the weakest link depending on chemical structure. They all have varying degrees of susceptibility to moisture, oxidation, ultraviolet, and heat. Polymers fatigue over time. Flex introduces hysteresis which produces heat build ups accelerating deterioration.

It's really easy to over analyze, especially if you have to guess at the polymer composition, fillers, and manufacturing methods. In the end your mileage is going to vary. Some folks will see much longer life than others. Impact on trees, sides of buildings, and hillsides, oddly, shorten propeller life. We live in an imperfect world.

So if asked, my technical answer would be to "carry spares" and change whenever it "feels" right.

Thanks. I have 2 full sets of spares. Should be okay for a while. I don't run into things much.
Would you say that isopropyl alcohol is safe on these blades (and the P4P shell, for that matter)?

 

[DefiantChild]

If the primary polymer is nylon (as has been suggested) then there should be little to no effect. APC molds their props out of 60% fiberglass reinforced nylon which, among many things, improves resistance to aqueous solutions.

I use a damp cloth with a little dish soap. Nylon is generally solvent resistant, can be sensitive to aqueous solutions, and susceptible to acids and alkalis. Stay away from strong solvents such as trichlorethalene and xylenol.

Been meaning to try some Pledge on the body (which I suspect is pvc) to see how effective a light wax coating works (and it has a fresh lemony scent).

 

[sideburn]

I just read on the DJI forum that unused propellers effectively have a shelf life of about 1 year because the threads will degrade with exposure to air. Further, they recommended that props be changed after 50 flights - no more than 100 flights. I assume that that is due to wear and tear on the threads ... of course the P4P does not have threads but the more robust quick connect.

I bought 2 extras pairs of props with my new P4P, so I have a total of "4 in use" and 8 spares.

These are of course the "quick connect" sort, so I assume the thicker material will not degrade with time - at least not as badly or quickly.

But otherwise, should I number my props and start rotating through all 3 "full sets"? Do they degrade due to UV?

Should I consider CF blades? Why do I think if I run into someone with the plastic blades I'll injure him and get sued, whereas if I run into him with CF blades it will eviscerate him ... and I'll still get sued?

Am I overthinking this?

People that sell propellers say this, nobody else does.

 

[Anthony58]

Seems excessive to me - and possibly very dangerous.

Props are not so expensive that i have to worry about them . I have 3 complete sets. I am also still using the set that came with my p3a. The threads are in great shape. Maybe I'm just not hard enough on my drone. But for the money i paid ,and my age,i cannot afford to break or lose it.

 

[AlanTheBeast]

Props are not so expensive that i have to worry about them . I have 3 complete sets. I am also still using the set that came with my p3a. The threads are in great shape. Maybe I'm just not hard enough on my drone. But for the money i paid ,and my age,i cannot afford to break or lose it.

I said "excessive" not expensive. I was talking about carbon fibre being excessively strong to the point of being dangerous. I have 4 full sets of "regular" props for the P4P.

I was born in Edmonton, BTW. Only been back once (flew out there in a Grumman Tiger with my father when I was 16 - great adventure). Been to Calgary a few times though.