So, this past holiday week I was in Maryland at the Wisp mountain ski resort.  I was trying to get my drone running on 3 good propellers and one that had a nick on the outside and had some issues.  At first, I thought maybe elevation or the temperature, which was -2 degrees F outside could be the issue.  I had one propeller that had about a quarter of an inch Nick taken out of one side from a previous tree branch crash.. lift off was possible, but normal elevation and position control were gimbal lock.. My first thought was the battery temp, which was was below recommended temps for flying.  So I warmed the battery next to fire place and immediately went outside to try again.. same problem...  After a bit of contemplation, I took the propeller that had the quarter inch Nick on the one side, measured defect, then took a pair of scissors and cut off the opposite side of the propeller relative to the defect.  Went outside and zoom.. all about balance and weight.  Although, I am sure if all 4 were in such condition; battery length would most likely be compromised... But it works

You may just want to get a couple sets of new props.

And looking at your collection, might want to be more careful.

I have a few dozen  new pairs of OEM DJI props, never flown with...

Why would you chance flying an expensive drone, with damaged props?


RedHotPoker

KM5RG-Robert Posted at 2017-1-27 21:16
You may just want to get a couple sets of new props.

And looking at your collection, might want to be more careful.

OK... The first three times I flew her was at night.. needless to say I have disassembled her 5 times in my first month..... Never a huge issue, like the CPU board.. surprisingly these guys are quite durable.. small issues here and there with firmware and breaking random stuff.. but all good

RedHotPoker Posted at 2017-1-27 21:24
I have a few dozen  new pairs of OEM DJI props, never flown with...

Why would you chance flying an expensive drone, with damaged props?

I actually enjoy the challenge of fixing things.. But, at the same time.. I am testing her limits.  Owned her fora month now...

RedHotPoker Posted at 2017-1-27 21:24
I have a few dozen  new pairs of OEM DJI props, never flown with...

Why would you chance flying an expensive drone, with damaged props?

Might I add, when I was initially flying her , it was more of a constant test at ten feet or less in an open area.. not purposely trying to destroy the ps3

Day_Dreamer Posted at 2017-1-27 21:35
Might I add, when I was initially flying her , it was more of a constant test at ten feet or less in an open area.. not purposely trying to destroy the ps3

Oh it's a Standard? Ok, carry on. Haha

Yeah, I understand. Going for broke. Flying it like you stole it. Crash and burn not intended... ;-)


Props are cheap enough, to have several spares. Don't fly near trees, they are drone-hazardous...  

Above all else, have fun. Chuckles


RedHotPoker

Day_Dreamer Posted at 2017-1-27 21:35
I actually enjoy the challenge of fixing things.. But, at the same time.. I am testing her limits.  Owned her fora month now...

If you crash, you will be fixing things. ;-)

Unnecessarily...


RedHotPoker

This is great, I love the idea of experimentation, but wow this is pretty extreme to try and use the props in this condition.
I could only recommend building a prop balancer using an old motor with the magnets out, and keep experimenting.

Flying with damaged props is like playing with fire and expecting not to get burnt.  A crash from even 10' up could damage your machine.  I always carry a full extra set.

RC_Wolf Posted at 2017-1-27 21:43
This is great, I love the idea of experimentation, but wow this is pretty extreme to try and use the props in this condition.
I could only recommend building a prop balancer using an old motor with the magnets out, and keep experimenting.

https://goo.gl/photos/S2m7G3TY3QNJhXMp7

So, from what I have found out due to experiment .. My personal theory:. Due to the light weight and incredible thrust of these new age drone, keeping an even altitude and an even horizontal distance is not affected greatly with broken balanced props.  Furthermore, balancing is not a critical measurement.  I did not use a micrometer or any scale to measure weight.  I simply took a measurement with a ruler and eyed up the cut on the other side...
On a note:. I have not eliminated propeller length past (in my assumption .4625" long on each end.

will , in my opinion be greatly decreased per distorted propeller.  

It seems that the sensors compensate for the drift of one or two propellers not producing an equivalent amount of fhryst

LOL. A Man who is not afraid! I love how your experimental daring just makes the conservatives squirm. I'm putting mini jato rockets on mine. ;-)

Hummingbird.UAV Posted at 2017-1-27 21:46
Flying with damaged props is like playing with fire and expecting not to get burnt.  A crash from even 10' up could damage your machine.  I always carry a full extra set.

To each his own.  I will not purposely place the PS3 in harm's way.. But, you only live once. . I'm curious.. and so far I give DJI props for making a durable product.  Although it seems customer service is the downside.. But, I can completely understand

Clapper Posted at 2017-1-27 22:22
LOL. A Man who is not afraid! I love how your experimental daring just makes the conservatives squirm. I'm putting mini jato rockets on mine. ;-)

Hahaha.. F yea

Clapper Posted at 2017-1-27 22:22
LOL. A Man who is not afraid! I love how your experimental daring just makes the conservatives squirm. I'm putting mini jato rockets on mine. ;-)

I'd love to see a picture of that hahaha

RC_Wolf Posted at 2017-1-27 22:48
I'd love to see a picture of that hahaha

I can do.. rather drunk on 2:19 A.M. SAT morning... But I do have things charged up.. video is gonna be shot like crap cause I can not control a camera while IME doing things.. but yea.. let's give it a whirl.. stand bye

Wait... F@$k.. rockets.. hmm.. be quite a task to drum up some heavy matilary on a Saturday morning.. ..

RC_Wolf Posted at 2017-1-27 22:48
I'd love to see a picture of that hahaha

So.. I am uploading a video to " Eww tube" as my daughter calls it.. taking a minute.. probably start a new thread so everyone can rip me for being crazy...lol

So.. mind you I am a fifth deep, and taking off in close proximity to the back of my house.. actually wish I got the complete takeoff on film.. but was rather occupied in not having her fly directly into the room my wife is currently sleeping in... Would be a total double F..

https://youtu.be/edyrUMP0NxQ

Day_Dreamer Posted at 2017-1-28 00:30
So.. mind you I am a fifth deep, and taking off in close proximity to the back of my house.. actually wish I got the complete takeoff on film.. but was rather occupied in not having her fly directly into the room my wife is currently sleeping in... Would be a total double F..

Imbed that bad boy...


Let's see what kind of trouble you might be getting into tonight? Haha



RedHotPoker

Day_Dreamer Posted at 2017-1-27 22:23
To each his own.  I will not purposely place the PS3 in harm's way.. But, you only live once. . I'm curious.. and so far I give DJI props for making a durable product.  Although it seems customer service is the downside.. But, I can completely understand

I can kinda commiserate with their customer service. If you spend any time on a lot of the drone boards there are a lot of folks lacking the good sense God gave a box of rocks.

CCrew Posted at 2017-1-28 06:46
I can kinda commiserate with their customer service. If you spend any time on a lot of the drone boards there are a lot of folks lacking the good sense God gave a box of rocks.

And that's why the FAA stepped in and is trying to regulate the r/c hobby to death.

RedHotPoker Posted at 2017-1-28 01:01
Imbed that bad boy...

https://youtu.be/edyrUMP0NxQ

Oh yea.. tied one on last night.  Only did that short flight as a demonstration.  I was not about to test her above 75 feet with the wind and dark.. But, it works.. so far

Day_Dreamer Posted at 2017-1-28 12:32
Oh yea.. tied one on last night.  Only did that short flight as a demonstration.  I was not about to test her above 75 feet with the wind and dark.. But, it works.. so far

I say this with all due respect to you, as I don't know you personally.
I don't have anything good to say about the video. Or your decision to fly it, with a damaged rotor blade.  Particularly while quite obviously, well too impaired to drive a motor vehicle. How the Hell do you think it's any different to take a medium sized, hobby class drone with its own impairment and fly it in a residential neighbourhood.  Then post your bravado on YouTube... Haha

Wow. & Your 'sober' face is clearly, if at a 90* angle, in the video too!?  I'd pull that video down. Before it gets too much attention.
I say this only because I care about our hobby, and we are already getting enough bad press from our own poor behaviour. . . People continue acting bad with drones, we'll all pay the price, and it won't be a happy occasion.  And you're probably a wonderful RC pilot on any given day...

What ever you do decide, please move forward with more thought to your perceived intentional behaviour. Thanks.

It's up to us all, to show our hobby in a positive and glowing light... Haha

RedHotPoker

Day_Dreamer Posted at 2017-1-27 23:34
Wait... F@$k.. rockets.. hmm.. be quite a task to drum up some heavy matilary on a Saturday morning.. ..

compromise and go with photoshop option.
I don't think doing it for real would be strapping a rocket to the drone more the other way around and definitely not financially viable.

it's quite amazing how well the IMU will cope with all the extra interference from increased vibration.
I was watching another demonstration on youtube a bloke made a point to clip the props for a particular demonstration.
They were not cut evenly, so this thing made a hell of a racket.  I was also impressed with the strength of the frame material handling the forces imposed by the extreme nature of the previous mentioned modification. That said, I don't think any preferred material for a small multi rotor build would handle that kind of punishment in repeated situations or any long duration before cracking or weakening would occur.
while this is a good experiment and I did enjoy observing the video for the science side of it, I'd have to agree with RedHotPoker that maybe flying while intoxicated is less advised to display on a public forum.

Actually, I wouldn't be surprised if stress cracks develop on the arms.  Such cracks have frequently occurred on Phantoms that are in good working order and never crashed or even been landed on the ground.

Ok ... lets bring this down to reality and earth level ....

Nicked / cracked / damaged / chipped props are bad news for motor bearings and mounts. You may not notice the extreme harmonics set up - but they do !!  Even if you balance out - they will still be exerting unnecessary harmonic vibration / stress.

Second - the reason the model in first post flew OK once opposite prop was 'nicked' similarly - was because of the Flight Controller which despite some peoples thinking its fancy - is a 6 axis Gyro / Accelerometer board. This means it will adjust each motor to suit the required command. Imagine 4 props and two are not equal to the others. You fit them opposites so to balance out logically. To the FC board - you have a machine that will play havoc with its internal programming. It will be constantly changing the motor commands - yes with 4 good props you get this - but now we are adding extra 3D unbalanced situation.

It is flyable ... but how long the machine will tolerate it is debatable.

Oh and to the FAA post above ... yeh yeh yeh .... fall back argument.
I agree that FAA has taken a dim view to multi-rotor use - but because of actual dangerous use in public places and interfering with Fire Fighting ... search parties .... recreation .... even to people walking in crowded New York streets !! Just to give a few examples.

Nigel

solentlife Posted at 2017-1-29 03:05
Ok ... lets bring this down to reality and earth level ....

Nicked / cracked / damaged / chipped props are bad news for motor bearings and mounts. You may not notice the extreme harmonics set up - but they do !!  Even if you balance out - they will still be exerting unnecessary harmonic vibration / stress.

I can completely agree on the real possibility of early motor failure if used consistently.  If the props are properly balanced, there should not be as much vibration, but more motor output to compensate for the lack of thrust produced by the prop.

solentlife Posted at 2017-1-29 03:05
Ok ... lets bring this down to reality and earth level ....

Nicked / cracked / damaged / chipped props are bad news for motor bearings and mounts. You may not notice the extreme harmonics set up - but they do !!  Even if you balance out - they will still be exerting unnecessary harmonic vibration / stress.

I can completely agree on the real possibility of early motor failure if used consistently.  If the props are properly balanced, there should not be as much vibration, but more motor output to compensate for the lack of thrust produced by the prop.

RedHotPoker Posted at 2017-1-28 13:09
I say this with all due respect to you, as I don't know you personally.
I don't have anything good to say about the video. Or your decision to fly it, with a damaged rotor blade.  Particularly while quite obviously, well too impaired to drive a motor vehicle. How the Hell do you think it's any different to take a medium sized, hobby class drone with its own impairment and fly it in a residential neighbourhood.  Then post your bravado on YouTube... Haha

I disagree with you on the perception of danger, and I doubt the FAA would be worried about me on a short test flight.  I was not attempting to fly it over the Whitehouse...Etc.   Non-the-less, to appease those concerned, I will set the video to private...

Day_Dreamer Posted at 2017-1-29 07:00
I disagree with you on the perception of danger, and I doubt the FAA would be worried about me on a short test flight.  I was not attempting to fly it over the Whitehouse...Etc.   Non-the-less, to appease those concerned, I will set the video to private...

DD ... ignore the Tree-huggers ... on this matter you posted.

I do not condone risky exercises - but I also appreciate that some will nudge the boundaries. You have 'nudged' a boundary - I don't think you have crossed the unacceptable line.

I'm classed as a 'trouble-maker' by odd ones here ... because I dare to not follow the DJI line ... but I take care to not be potential risk to others.

Nigel

solentlife Posted at 2017-1-29 07:28
DD ... ignore the Tree-huggers ... on this matter you posted.

I do not condone risky exercises - but I also appreciate that some will nudge the boundaries. You have 'nudged' a boundary - I don't think you have crossed the unacceptable line.

Ahh.  A fellow libertarian!  Agreed, you only live once.

Day_Dreamer Posted at 2017-1-29 07:00
I disagree with you on the perception of danger, and I doubt the FAA would be worried about me on a short test flight.  I was not attempting to fly it over the Whitehouse...Etc.   Non-the-less, to appease those concerned, I will set the video to private...

You were drunk, while operating a small aircraft. Use common sense.


RedHotPoker

You might get away with flying with damaged props for a little while but you must realize that the shafts and bearings in the little motors aren't strong enough to last very long with such an unbalanced load. You may also start getting stress cracks in the body around the motors. Be careful, fly wise and safe.

RedHotPoker Posted at 2017-1-29 10:37
You were drunk, while operating a small aircraft. Use common sense.

I drunk a fifth of water, and tied one on, (the props) last night..  haha.. theatrics my friend..

Day_Dreamer Posted at 2017-1-29 15:50
I drunk a fifth of water, and tied one on, (the props) last night..  haha.. theatrics my friend..

AA Captain Morgan ...?  Ha


RedHotPoker

solentlife Posted at 2017-1-29 03:05
Ok ... lets bring this down to reality and earth level ....

Nicked / cracked / damaged / chipped props are bad news for motor bearings and mounts. You may not notice the extreme harmonics set up - but they do !!  Even if you balance out - they will still be exerting unnecessary harmonic vibration / stress.

So long as each individual prop is balanced there should be no nasty vibrations, harmonics or overloaded flight controller. The only thing the flight control processor does is vary the individual motor speed and if one prop has less lift because it's shorter or has been flattened out then that motor will be spun faster to compensate so the aircraft stays in the correct orientation (horizontal at no airspeed or leaning into the direction of travel).

It would be similar to adding an off center weight to a Phantom, and I would expect that if the prop was too short or flat to give the required lift at maximum motor speed then the other motors would have their power reduced to keep the correct orientation even if that meant that the air craft couldn't take off. The flight controller simply would not allow liftoff if there was too little lift from one prop or too much weight on one side to allow the aircraft to stay horizontal during liftoff.

An interesting demonstration of the flight control system is to bring the aircraft within reach and release the controls. Grab the Phantoms leg and (gently) try to rock it or pull it (anyone who hand catches will regularly experience this). Talk about a cranky swarm of bees as the aircraft fights to regain control from the unknown source of instability, you can see the props on the "high" side reduce speed while the "low" side is ramped up instantly to maximum power and if you rock it from side to side, wow.

Quamera Posted at 2017-1-29 16:58
So long as each individual prop is balanced there should be no nasty vibrations, harmonics or overloaded flight controller. The only thing the flight control processor does is vary the individual motor speed and if one prop has less lift because it's shorter or has been flattened out then that motor will be spun faster to compensate so the aircraft stays in the correct orientation (horizontal at no airspeed or leaning into the direction of travel).

It would be similar to adding an off center weight to a Phantom, and I would expect that if the prop was too short or flat to give the required lift at maximum motor speed then the other motors would have their power reduced to keep the correct orientation even if that meant that the air craft couldn't take off. The flight controller simply would not allow liftoff if there was too little lift from one prop or too much weight on one side to allow the aircraft to stay horizontal during liftoff.

That is actually a great idea.  I experienced this once after a small crash and the Phantom ended up side-ways.  When I picked her up she immediately tried to retake off to Home and started pulling me like an untrained dog down the yard.  Really caught me off guard the first time as the thrust produced is rather significant..

I am not surprised that it flies with the reduced props. Any device like this will have margins of performance. You are just eating into those. When you take too large a bite that is when you get bitten, as well as whatever (or whoever) you hit.

Don't mind you doing the "experiments" as long as it's only your property and health you are putting at risk. Probably not the best idea to do this in a manner where the risk of damages extends beyond that scope.