What type of props

Macsgrafs

Macsgrafs

Active Member
I'm wondering if you use standard RC aircraft props or sly fly props? This is to go on a motor producing 2.3Kg of thrust (2820). I will hopefully be using 4S lipos & was wondering if anyone knew of a good starting size prop. I am going to buy 4 different sizes starting at 12 x 6 & working up in size to find one that gives max thrust, but lowest current draw.

Ross
 


Bartman

Bartman

Welcome to MultiRotorForums.com!!
Ross,
Getting a multi-rotor set up to fly correctly is more a black art than anything logical. Getting the weight, power, props, radio settings, firmware settings, etc. just right takes time and patience. Which motors are they? 2820? Is that the Pulso model number? I'm not familiar, sorry. The Roxxy 2827-35's do well with the Graupner 10x5 props and some of us have special ordered the Xoar 10x5's. DennyR said it somewhere else and I agree completely that things perform better when the motors are working harder so that steers you towards smaller props spinning faster. You're mileage may vary, YMMV.
Bart
 

Macsgrafs

Macsgrafs

Active Member
Droider said:
Ross have a chat with Paul at Electricwingman.co.uk.. He is a mind of info

Dave
Click to expand...

Thanks Dave, will do.

Bartman said:
Ross,
Getting a multi-rotor set up to fly correctly is more a black art than anything logical. Getting the weight, power, props, radio settings, firmware settings, etc. just right takes time and patience. Which motors are they? 2820? Is that the Pulso model number? I'm not familiar, sorry. The Roxxy 2827-35's do well with the Graupner 10x5 props and some of us have special ordered the Xoar 10x5's. DennyR said it somewhere else and I agree completely that things perform better when the motors are working harder so that steers you towards smaller props spinning faster. You're mileage may vary, YMMV.
Bart
Click to expand...

The motor is an Emax GT 2820, it says 12x6, but I dont know if I should use a standard aircraft prop or should it be a slowfly jobbie? Oh well I'm sure 4 or 5 props later, with my current meter & scales for weighing thrust I can sort something out ;)

Ross
 

Pano-Dirk

Pano-Dirk

Member
The 12x6 has more thrust by high rotation speed as the 12x3,8, but the 3,8 gives more pressure by lower rotation speed.
If you want a stable hover platform, the 3,8 or 4,5 is better, if it is a heavy copter, than the 12x6 is better. If you want a fast copter for acrobatics, the 12x6 is better.

The Emax GT 2820 is a heavy and powerful motor and you can use 14x4,7 propellers with much more thrust as the 12x6 and good hovering performance.
This is the good part, the negative part is, that a heavier propeller is bad for the regulation.

You have to decide what you want. First you have to choose the right motor for the maximum copter weight. Next step is the propeller. Good and stable hovering or fast and agility?

I am using 12x6 for a copter with a weight of 5 Kg.

Dirk
 
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Macsgrafs

Macsgrafs

Active Member
Pano-Dirk said:
The 12x6 has more thrust by high rotation speed as the 12x3,8, but the 3,8 gives more pressure by lower rotation speed.
If you want a stable hover platform, the 3,8 or 4,5 is better, if it is a heavy copter, than the 12x6 is better. If you want a fast copter for acrobatics, the 12x6 is better.

The Emax GT 2820 is a heavy and powerful motor and you can use 14x4,7 propellers with much more thrust as the 12x6 and good hovering performance.
This is the good part, the negative part is, that a heavier propeller is bad for the regulation.

You have to decide what you want. First you have to choose the right motor for the maximum copter weight. Next step is the propeller. Good and stable hovering or fast and agility?

I am using 12x6 for a copter with a weight of 5 Kg.

Dirk
Click to expand...

Thanks Dirk, it seems from reading your examples that I need A larger prop. Im NOT after speed. but stability as its a camera ship. I already have 2 events lined up for me to film, both over water..I seem to get all the water jobs for some reason ;)
Whatever happens I dont want it to twitchy!
Thanks again for your most welcome advice

Ross
 


Macsgrafs

Macsgrafs

Active Member
Shaun, your last post never went through :(
I was still wondering if IO need slow fly or standard aircraft props???

Ross
 

B

baker55

Member
Hi Ross,they sell them at Quadrocopter.us but I haven't received a reply on what the advantage if any would be for my AD6. Shaun
 




Macsgrafs

Macsgrafs

Active Member



R

Ryan Thomas

Member

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1

1001 Copters

Member
Hi,
be carefull this curve is giving the thrust versus intensity. If the test is made with a LiPo instead than with a stabilised alimentation the result isn't correct: you have a voltage drop along time on LiPo and the power consumed by the motor is different along the test. It's better to have curves with thrust vs power.

About the APC props, be carefull, according to manufacturer data we are out of range on most of our applications. On this page there is the RPM limit for APC props:
http://www.apcprop.com/v/html/rpm_limits.html

APC Suggested RPM Limits

Glow Engine and Speed 400 Electric Props

Maximum RPM=190,000/prop diameter (inches)
(For example, a 10x6 glow engine prop should be limited to 19,000 RPM)


Thin Electrics and Folding Electric Props

Maximum RPM=145,000/prop diameter (inches)

Slow Flyer props

Maximum RPM=65,000/prop diameter (inches)


Racing Props

8.75 N,W and 8.8 series 40 Pylon props
Maximum RPM=225,000/Prop diameter (inches)
Click to expand...

this mean that the RPM limit for a 12x3.8 APC slow fly is 5417 rpm. On a Mk3538 with 60% of the gaz calculation gives 5300rpm and at 70% of gaz 6200rpm.
here's an excell sheet made by a french MK member:
View attachment 369

So yes initialy the propeller sold with MK kit weren't adaptated to our use...
 

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Droider

Droider

Drone Enthusiast
Sorry 1001 I aint sure of your first name..

Very good info to me. What props do you recon are the best as you have obviously researched the subject.

Dave
 


1

1001 Copters

Member
Hi Droider,
my other nickname on boards is catlord and IRL my name is Cedric :)

Well my point of view can be submited to judgement because I'm actually selling propellers but here it is anyway:
I choose to use XOAR prop on heavy lift configuration for several reasons:

First : the prop are very stiff
second : XOAR is the only manufacturer that is proposing "precision apparaired props" and this fits eaxctly our application: these props cost 20% more than normal XOAR prop because it's manufactured on the same machine by the same guy. Xoar warranty that the prop have the same pitch, same angle of attack and same weight. WHen Ireceive the prop I measure the weight of each one and I make pairs (every pair is within 0.4gr).
Third: the weight. XOAR props weight (for 13x6.5") is between 18 and 23gr but majority is around 20/21gr This is 60% lighter than APC of the same size and even lighter than the new Simon's jardine props (carbon fiber) Perhaps because these carbon props are made on the same shape than APC. As you know probably: the lighter the porp is, the lower the vibration amplitude generated will be.
Fourth: these props can handle 2.2kg at 6000rpm and more than 3kg at 8000rpm. rpm limit is 10 000, far far away from the RMP APC limits.

I have had several customers return about the good quality and the smooth flight you have after balancing these props so this is my best choice for the moment :) I have to do several test on different size /different motors, I must find the time to do it ...
 

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