Did a Quadcopter scratch build which I designed the entire frame and 3D printed it and assembled. Looking at thrust data for motors I went with 2208's and am running 6045 tri-props on it (data says ~800g thrust). The frame size itself is about 350-400mm, and I have flown it a few times with good results. I was wondering what differences in flight I would notice by putting 2216 motors with 1045 propellers on it (data says ~1000g thrust). I am looking to this as I see it would be more efficient and I would expect longer flights. Thoughts? what other things would I notice doing this? would you advise doing this? and why? Reading says that it would be more susceptible to wind, is that true? Also would this be less responsive in thrust, therefore not drop as fast when i decrease throttle? Just looking for advice here, thank you!!
Help! Propeller/Motor flight characteristics
- Thread starter hodj917
- Start date
Can you post the specs (or links to the specs) for the actual motors? In addition to the thrust numbers you have posted, the current draw at the various prop sizes will influence the flight times. Also the power setup you are using (3S, 4S, battery capacity) could be helpful.
I am not an experienced quad guy, but I have been playing with the same kinds of combinations on a cheap-and-cheerful foamboard quad to learn some flying and FPV skills.
DamoRC
I am not an experienced quad guy, but I have been playing with the same kinds of combinations on a cheap-and-cheerful foamboard quad to learn some flying and FPV skills.
DamoRC
This is what i am using (3s, 6x4.5x3)
https://rotorgeeks.com/cobra-2208-2000kv
This is what i am looking at (3s, 1045)
https://image.getfpv.com/catalog/pr...e35df139433887a97daa66f/f/m/fm-2216-stats.png
I would expect longer flight times given the amp draw difference, but looking for second opinion on that as well as other flight characteristics that would change (i.e. slower acceleration, more drift in wind, less throttle response...)
Thanks
Namactual
Elite member
Just going off of the info you posted lets compare.
2200kv 6x4.5x3 vs 900vk 10x4.5
Watts: 250 vs 147
Thrust: 840 vs 1000
Pitch Speed on 3s: 104.06mph vs 42.57mph
More efficient and more thrust at a lower speed.
You will fly longer, accelerate faster and/or carry more weight, but have half of the max speed.
Edit: this is a very generalized statement, you will never reach those pitch speeds in the real world for example.
2200kv 6x4.5x3 vs 900vk 10x4.5
Watts: 250 vs 147
Thrust: 840 vs 1000
Pitch Speed on 3s: 104.06mph vs 42.57mph
More efficient and more thrust at a lower speed.
You will fly longer, accelerate faster and/or carry more weight, but have half of the max speed.
Edit: this is a very generalized statement, you will never reach those pitch speeds in the real world for example.
Thank you for the Info, do you think hover sensitivity would go up or down with the larger props? I am ok with the slower max speed as I am new to flying and am ok if it is a bit more sluggish than a rocket.. It seems to be a smart switch/upgrade as I would get the longer flight times and be able to add a camera with gimbal
Namactual
Elite member
I am not sure what hover sensitivity means? Sorry, I am not a quad guy. Not yet anyway.
All I can say is all things being equal, having a higher thrust to weight ratio will give you more responsive handling. I am going to guess that having the larger rotational mass and more torque will allow it to yaw faster as well?
Again, with all things being equal.
Adding more weight, camera w/ gimbal, will nullify those gains to a fraction depending on how much extra weight you add.
Don't forget about inertia. Having 300grams of extra thrust and adding a 300gram camera are equal at 1g of acceleration, but @ 2g's your camera weighs 600grams and you still only have an extra 300grams of extra thrust.
All I can say is all things being equal, having a higher thrust to weight ratio will give you more responsive handling. I am going to guess that having the larger rotational mass and more torque will allow it to yaw faster as well?
Again, with all things being equal.Adding more weight, camera w/ gimbal, will nullify those gains to a fraction depending on how much extra weight you add.
Don't forget about inertia. Having 300grams of extra thrust and adding a 300gram camera are equal at 1g of acceleration, but @ 2g's your camera weighs 600grams and you still only have an extra 300grams of extra thrust.
What I currently notice is if I move the throttle just a little than it will rise/fall fairly quickly. I have expo on pitch and roll and a throttle curve to make the middle 1/3rd with less slope than the outer 1/3 on each side. Knowing the propeller will be larger and have more inertia as well my thought is it will take longer to spin up and slow down therefore be less responsive around hover throttle (this is where the sensitivity i was talking about comes in). Does this logic make sense? that with small movements in throttle it would take the propellers longer to speed up/slow down unlike the smaller propellers?
I think that your "hover sensitivity" might be hard to assess based on the available numbers because it would depend on the available torque of the motor at hover RPM compared to the inertia of the props. It is possible that the 2216 motor has the torque to accelerate the 10 inch prop at the same or greater rate than the 2206 motor and 6 inch prop combo making it just as sensitive to slight changes in throttle at hover. Not a particularly satisfying answer, I know, but its a complicated question ( I think )
Also, although I agree with the assessment made by @Namactual (longer run times with the bigger motor prop combo) , again - this might be complicated. The numbers provided by the manufacturers for amp draw and thrust are at wide open throttle which is only part of the story. Also, there is the difference in weights of the motors, you current motor being 40g and the proposed 2216 motor being 75 grams per the manufacturers data. So moving to the bigger motor will add ~140 grams to your build. So you may still get longer runs times, but perhaps not as long as the wide open throttle data might suggest because you are carrying extra weight.
The only way to really know would be to get the motors and props and test them out or perhaps look at some of the online calculators for motor / prop combos such as e-Calc.
If you do go ahead and get the motors I would love to see the results.
DamoRC
)Also, although I agree with the assessment made by @Namactual (longer run times with the bigger motor prop combo) , again - this might be complicated. The numbers provided by the manufacturers for amp draw and thrust are at wide open throttle which is only part of the story. Also, there is the difference in weights of the motors, you current motor being 40g and the proposed 2216 motor being 75 grams per the manufacturers data. So moving to the bigger motor will add ~140 grams to your build. So you may still get longer runs times, but perhaps not as long as the wide open throttle data might suggest because you are carrying extra weight.
The only way to really know would be to get the motors and props and test them out or perhaps look at some of the online calculators for motor / prop combos such as e-Calc.
If you do go ahead and get the motors I would love to see the results.
DamoRC
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