Impressive work!

I am currently in the process of completing two Apex Micro 4" quads using RCINPOWER Smoox 1507 2680 Kv motors respectively T-motor 1507 2700 kv motors. Thus, I am especailly interested in the pending results of the 1408 2800kv testing.

Cheers!

RCinPower 1507 is pretty good.
2680KV is bit low for 4S.

I have Apex1607 (slightly bigger version).
They have 3350KV which is EXCELLENT fit for 4S.. something like 900g thrust!

(16-Apr-2022, 08:13 AM)romangpro Wrote: RCinPower 1507 is pretty good.
2680KV is bit low for 4S.

I have Apex1607 (slightly bigger version).
They have 3350KV which is EXCELLENT fit for 4S.. something like 900g thrust!

I think I'm going to quote you in the future based on some preliminary results I'm getting on some testing.

Do you know if they have t-mount motors, or just 5mm? I can't find any t-mount with that Kv for any motor around that size, but my Googlefu might just be terrible.

(16-Apr-2022, 08:13 AM)romangpro Wrote: RCinPower 1507 is pretty good.
2680KV is bit low for 4S.

Good to hear.

It seems 1507 motors are typically designed for 3" props.  I want to use 4" props and therefore selected the lower kv version. This may be a bit low but the datasheet for the RCINPOWER 1507 motor indicates that HQ 4x3x4 prop is actually a quite decent compromise @ 2680 kv and 4S (675 g of thrust with an efficiency of 3.9g/W ).

The AUW of my 4" quads will be less than 320g (4S / 850mAh) i.e. assuming the datasheet is accurate I think kv ~2700 will be reasonable providing enough thrust. At least for my flying style/skills ...

(16-Apr-2022, 05:44 PM)3dxspin Wrote: Good to hear.

It seems 1507 motors are typically designed for 3" props.  I want to use 4" props and therefore selected the lower kv version. This may be a bit low but the datasheet for the RCINPOWER 1507 motor indicates that HQ 4x3x4 prop is actually a quite decent compromise @ 2680 kv and 4S (675 g of thrust with an efficiency of 3.9g/W ).

The AUW of my 4" quads will be less than 320g (4S / 850mAh) i.e. assuming the datasheet is accurate I think kv ~2700 will be reasonable providing enough thrust. At least for my flying style/skills ...

Just to help you out here even though all my data isn't compiled/analyzed, I can say with confidence that 850mah is overkill for that setup. Go with 650 to lower the weight unless your focus is long range with long flight times. Where those motors will shine as you're suggesting is ultra efficiency, but you'll lose top end so you'll want to keep the battery weight down to allow you to go faster and be more agile (thrust/weight ratio) since you won't need the current from a larger one. I'm seriously debating building something similar, so I've put a bunch of theory-craft calculations into what you're looking to build. I'm giving away some future results here a bit but I'd rather that then see you get the motor/prop/battery balance wrong. This is with the potentially inaccurate assumption that those motors will perform similar to the 1408's I'm testing.

As a bonus if you make the build allow for 6s voltage you could throw on a 6s battery with 3"-3.5" props and have a dual purpose build.

(16-Apr-2022, 07:00 PM)Recursion Wrote: Just to help you out here even though all my data isn't compiled/analyzed, I can say with confidence that 850mah is overkill for that setup. Go with 650 to lower the weight unless your focus is long range with long flight times. Where those motors will shine as you're suggesting is ultra efficiency, but you'll lose top end so you'll want to keep the battery weight down to allow you to go faster and be more agile (thrust/weight ratio) since you won't need the current from a larger one. I'm seriously debating building something similar, so I've put a bunch of theory-craft calculations into what you're looking to build. I'm giving away some future results here a bit but I'd rather that then see you get the motor/prop/battery balance wrong. This is with the potentially inaccurate assumption that those motors will perform similar to the 1408's I'm testing.

As a bonus if you make the build allow for 6s voltage you could throw on a 6s battery with 3"-3.5" props and have a dual purpose build.

Thanks for input.

Yes, I aiming for a dual use drone best described as a "mid-range freestyle" drone. I do have 650 mAh 4S batteries as an option but is a little bit concerned with the max C-rating depending on the max current draw of used prop/motor combination.

Its a LOT of testing.

My priority is efficiency, but also good response, which quad66 / karlpablo covered for 1202.5 motors.

In 2019 I went from heavy big power 6S to ultralight toothpicks.

On your graphs, horizontal axis motor % is kinda useless.. better to have thrust.

Top3 interesting builds
1. TP3. You could compare all 1204, 1204.5 and 1303.5 motors. Ideally do tests with 3018, 3016*3, and maybe 2 more.

2. 4" ultralight. Compare 1404 3000KV motors. Maybe include 1504 or 1603. Hyperlite 1404.5. HQ4025, GF4024. Floppy

3. 1S 3". 1203 and 1202.6 motors.

The current 3.5" performance and efficiency leader is the HQProp T3.5x2x3, and now HQProp released a new version of the 3.5" propeller with a more aggressive pitch. I wanted to test and see if the more aggressive pitch would be an overall improvement, or overall end up being worse for performance, efficiency, or both.

Here is the video outlining the testing, results, with my analysis of the results:



The Motors tested in this test:

• T-Motor F1404 3800kV
  

The propellers used in this test:

• HQProp T3.5x2x3
  
• HQProp T3.5x2.5x3
  

Reference Charts

Thrust by Motor Utilization


Thrust Differential (Grams of thrust)


Thrust Differential (in percent)


Efficiency by Motor Utilization


Grams of Thrust to Watts of Power


RPM by Throttle Range

I just received some HQProp T3.5x2.2x2 propellers I ordered. It should be interesting to see how much more efficient they are (or not) vs the T3.5x2.5x3 propellers.

This took longer to get published since I had burned out a bit, put a lot of my engineering effort into improving my 3.5" build (Scythe), and with limited time I was focused on getting flying in for the remainder of the season. I'm going to try and poop out more analysis over the winter.

--------------------

I wanted to compare the 2 blade 3.5" propeller released (which I think is still the only one?) by HQ Prop against the 3 blade to see what the advantages or disadvantages were in potentially using them instead of the 3 blade, hoping that at least for long range it might make a lot of sense.

Here is the video outlining the testing, results, with my analysis of the results:



The Motors tested in this test:

• T-Motor F1404 3800kV
  

The propellers used in this test:

• HQProp T3.5x2.2x3x2
  
• HQProp T3.5x2.5x3
  

Reference Charts

Propeller Weight


Thrust by Motor Utilization


3 Blade Thrust Differential (Grams of thrust)


3 Blade Thrust Differential (in percent)


Efficiency by Motor Utilization


2 Blade Efficiency by Motor Utilization % differential


Grams of Thrust to Watts of Power


RPM by Throttle Range


Spin up to 95% throttle (RPM)


Spin up to 95% throttle (correlated thrust)

This is really fantastic testing. Thanks for putting it all together and sharing the detailed results.

(27-Dec-2022, 05:47 AM)Construct Wrote: This is really fantastic testing. Thanks for putting it all together and sharing the detailed results.

Thanks bud. I appreciate that.

Very cool! I'm glad you have rpm in the testing! I find it crazy how much rpm we lose when loading up these smaller motors but they can handle it! Drone motor testing is so much different than airplane motor testing. I shoot for 10% rpm loss from max rpm based off kv as being ideal for prop/motor combo for planes. Drone motors are a totally different approach as we mainly need to focus on keeping within current limits and find a prop that works good for your application whether it be speed or technical flying.

I wanted to see if 4" would be viable on lower 2800Kv motors against 3.5", so I tested a ton of props on a T-Motor F1408 2800Kv motor.

The video analysis goes into a bit more detail chart wise than listed here (since they need context), and I also spend the second half theory crafting potential builds against my current 3.5" build to see if it makes sense.

You can find that here:



The Motors tested in this test:

• T-Motor F1404 3800K
  
• T-Motor F1408 2800Kv
  

The propellers used in this test:

• HQProp T4x2.5x2-PC
  
• HQProp T4x2x3-PC
  
• Gemfan Hurricane 4024-2
  
• Gemfan Hurricane 4023-3
  
• HQProp T3.5x2.5x3-PC
  

Reference Charts

Propeller Weight


Thrust by Motor Utilization


Efficiency by Motor Utilization


Grams of Thrust to Watts of Power

This one probably has taken me the most time to analyze. I wanted to understand if 5" sub-250 drone builds are viable, and if so, which motors and propellers would work well together, or would perform poorly, so this test was dedicated to 5".

You can see the video with the tests, analysis, and build theory. I break down the graphs quite a bit and add a ton more detail because of how much there was to go through. The pictures I'll post here are a bit messy, but still good for reference.  Video:



Motors tested in this video are:
- T-Motor F2004 3000Kv
- Ummagawd Aerolite 2004 2400Kv
- T-Motor F1404 3800Kv

Propellers tested in this video are:
- HQProp T5x3x2PC  
- HQProp T5x2x3
- Gemfan Long-Range 5126-2
- Gemfan Super Light 5130-3
- Gemfan Hurricane 5125-3
- HQProp T3.5x2.5x3



Reference Charts

Propeller Weight


Motor Weight



Thrust by Motor Utilization


Efficiency by Motor Utilization


Grams of Thrust to Watts of Power


Motor Spin up to 85% Throttle (RPM)


Motor Spin up to 85% Throttle (Thrust)


Motor Spin up to 25,300 RPM