Do you unfold your props everytime before starting motors?

Ursus Horribilis · Jul 8, 2017

Do you have the link to this video?

Bud

Masheen said:
The tutorial i seen on YT explaining this procedure and frequency used to power motors in this setting seemed convincing.

Ursus Horribilis · Jul 8, 2017

Ok, thank you.

Bud

Masheen said:
I just had a look back through my history but couldnt find it.
I will post it if i come across it and dont think it was from official source but was interesting.

Lelantos · Jul 8, 2017

I usually don't unfold. I see no good reason to. I also use auto take-off most of the time.

I inspect the blades when folding them after a flight.
The software accounts for blades being folded. If you'll notice, when taking off the motors do a pre-spin before applying power for take off.

Lelantos · Jul 8, 2017

Masheen said:
aww man are you serious?
Do you have any info on the pre-spin ;-)

Serious? Yes. The pre-spin is observable. Two short bursts to the motors, then they spin up to normal flying speed. Since the motors are controlled by software, well that's why I said that the software accounts for that. There is also the supposition that the pre-spin is intended to test for loose props. Either way, the two shorts bursts of power serve to open up the folded props prior to the application of full power.

Hauptmann · Jul 8, 2017

Slantnose79 said:
I get them 80% unfolded and let centrifugal force do the rest...
Sent from my iPhone using MavicPilots

Before each flight, I unfold them most of the way when I check them for condition and tightness.

EsiMavic · Jul 8, 2017

I unfold it because when it's folded when I the start the motors the mp makes some jerk movements. I just what a smooth motor start for the safety of my mp

Geo · Jul 10, 2017

Brutus said:
I alway unfold them, with three things in mind:

It only takes me five seconds to do so.

If there is a problem with the props, this is an extra chance to recognize it.

There's a big unbalance before centrifugal force straighten the blades which creates unnecessary load at the motor bearings.

#3 is probably the most important over time

Lelantos · Jul 10, 2017

Geo said:
#3 is probably the most important over time

Respectfully, I disagree. I very much doubt that the tiny radial forces that exist for a fraction of a second during spin-up contribute at all to premature bearing wear.

Steve1966 · Jul 10, 2017

Random Mavic Prop Question

Steve1966 · Jul 10, 2017

Steve1966 · Jul 10, 2017

Steve1966 · Jul 10, 2017

As you can see within 3 revs they are open but you should check them every time you spin them up

optiplex · Jul 10, 2017

starting the motors with props folded causes them to vibrate badly for a second, shaking the entire craft
just like starting a heli with props not fully unfolded, this bad vibrations cant be good for the mavic

geigy · Jul 10, 2017

Naah - life is too short. The props do a great job of extending themselves, it's zero effort, so delegate.

Lelantos · Jul 10, 2017

optiplex said:
starting the motors with props folded causes them to vibrate badly for a second, shaking the entire craft
just like starting a heli with props not fully unfolded, this bad vibrations cant be good for the mavic

It is not at all like starting a heli with the blades not fully unfolded, the Mavic shakes a little for only a fraction of a second. An unbalanced heli can shake violently for several seconds while spinning up, with the possibility of bending the main shaft or other problems.

While I agree that a folded spin-up can't be good for the Mavic, that does not mean that it is harmful to it. You could do some math and calculate the actual forces on the bearings, then compare that to the ratings of some generic similar sized bearings. I think you will find that the forces don't come close to anything that would cause problems.

Yes, failing to unfold the props will cause additional stress. That is certain, but the additional stress is insignificant. Actually flying the Mavic for a couple seconds will cause more wear and tear.

optiplex · Jul 10, 2017

Lelantos said:
It is not at all like starting a heli with the blades not fully unfolded, the Mavic shakes a little for only a fraction of a second. An unbalanced heli can shake violently for several seconds while spinning up, with the possibility of bending the main shaft or other problems.

While I agree that a folded spin-up can't be good for the Mavic, that does not mean that it is harmful to it. You could do some math and calculate the actual forces on the bearings, then compare that to the ratings of some generic similar sized bearings. I think you will find that the forces don't come close to anything that would cause problems.

Yes, failing to unfold the props will cause additional stress. That is certain, but the additional stress is insignificant. Actually flying the Mavic for a couple seconds will cause more wear and tear.

so why add to that already stress of the flight the insignificant stress of the folded props
its about 2 seconds total to un-fold them
i think its plain lazyness

Lelantos · Jul 10, 2017

optiplex said:
... why add to that already stress of the flight the insignificant stress of the folded props
its about 2 seconds total to un-fold them
i think its plain lazyness

Why? Because it is not necessary - there is no tangible benefit for me. The keyword here is "insignificant". To say it is "plain lazyness" in insulting. There are countless unnecessary things that people don't bother doing. It is not because they are lazy, it because those things don't need to be done. If it makes you feel better, or gives you more confidence in the Mavic, then by all means unfold the props manually. It is not a waste of time if you get some benefit out of it.