07xx vs 11xx Brushless Motors for a Whoop?


#1

Now that my brushed FC is on the fritz, I’m thinking about helping to design an indoor brushed whoop, possibly with ducts.

A couple questions for those who already have these size motors.

1.How do the 07xx brushless motors normally break? Is it in a crash or do the bearings wear out over time?

  1. Are the 1102/03/04 brushless motors much more durable and last much longer (until you crash them badly?)

  2. Also, how much noisier are these motors on 1s/2s than 65mm brushed whoop motors?

  3. What’s the main reason it’s hard to fly brushless indoors? Does it simply come down to throttle control?


#2

I can share with you my opinions that I have formulated after asking myself very similar questions for the same reason as you. At a certain point I felt that whooping should be pushed to the next level (brushless) after feeling like I had found the limits of brushed durability and performance … and wanting more. However, I still have not jumped in on a brushless whoop so these are the opinions of someone that is holding back after doing research - and has not tried it yet. I do plan to build out one just to see if my guesses are right.

  1. I believe most accounts of 0703 burning out are from prop strikes that momentarily stop rotation, cause current to spike, and toast the windings. A good portion of them are assumed to be DOA but likely were killed by a winding breaking during handling through the build process. Conclusion - windings are weak.

  2. 11xx motors are very durable. Most accounts of winding failure during handling and physical construction failure during crashes are from racerstar 1103 1st Gen. And I myself do own those and 2 other flavors of 1102 which have survived nothing short of punishment. Bearings in my 1102 seem to be the first thing to go south.

  3. Motors themselves aren’t the source of noise - it’s the props you put on them, the rpm you spin them up to, and how quickly the motor can change that rpm. I’ve not tried any props smaller than 57mm on brushless but some of them scream like the world is coming to an end and others are oddly quiet.

  4. The main reason I don’t fly anything inside but a standard 6 or 7mm whoop is that after much of my own testing - I came to the conclusion that a whoop is just the perfect tool for the job. I even built a 6mm craft that weighs 2 grams less than my whoop, has no ducts, and put 46mm props on it for a bit more grip and power. Result - I created an outdoor craft that was too loose around corners and too fast to really enjoy inside. Conclusion - the ducts, the prop size, and the all up weight come together in a whoop to make it the perfect indoor craft. If you’re gonna go brushless - make sure you keep all three of these things constant - same as a brushed whoop… or it will not whoop. It will just be a tiny outdoor craft.

At the end of all my experiments to change something about the whoop we know and love to make it better - I came to essentially one conclusion. To leave it alone. I actually reverted a bit and really enjoy my 6mm whoop over my 7mm whoop cause it just handles better (less momentum). That said I did uncover one super secret key to ultimate whoop performance - the only thing that should be changed… and it’s the height of the ducts. I have printed and built hundreds of variations on whoop frames and formats. When duct height is limited to about 6mm - performance skyrockets and handling (the ability to whoop and feel like a whoop) seems to remain unchanged. This is the only variation on the whoop format left to be discovered by the “mainstream” in my opinion. I hope to find both the time and the right design and material to make this 6mm duct height frame possible with the same durability we have come to expect in a manufactured frame. Time will tell if I’m successful.

Back on topic of a brushless whoop though - I will go 0703 (maybe 0705 if I can get weight right) on 1s with stock whoop props and a frame that resembles the standard whoop frame in an attempt to keep weight similar, props the same, and the ducts the same because without those three - it will fly but it just won’t whoop IMHO.

Happy new year my friends!!!


#3

Thanks for the detailed reply.

I may end up giving it a shot. Worse that happens is I’ll get another outdoor craft haha!


#4

Do keep us posted on what configuration you try!


#5

Will do! :smiley:


#6

If you want, I’m building something like a whoop with 705 motors, and would be happy to show you my findings. The parts should be here tomorrow…


#7

Betafpv is trying to get close. The weight was higher than I was expecting:
Weight: 38g (without props guard) / 44g (without battery)

I agree with NFE, still nothing beats 6/7mm whoop builds for indoor flying.


#8

That’s would be awesome! What’s your parts list?

I was looking at fishPepper FC and ESC. Not sure about lipo capacity, but they’re a lot of choices. I’m putting together an Excel table of possible combinations, but 07xx motors don’t seem to have many good thrust tests done.

If I 3D print my own frame and use a spare AIO Cam, I can get a brushless whoop plus six lipos for under $80!


#9

Racerstar 705 BL motors, but will probably upgrade
2s flight controller stack, w/ 6a esc from BG
40mm props for ducted fans
Some “pro micro” flysky reciever
1 and 2s batteries 250mAh to 500mAh
Angry oskie 3d printed frame
This was meant as a demo model for people to see, specifically schools, family, and friends. No hard core acro for this guy…


#10

There’s a guy named Steven Merrell who has been posting in the Tiny Whoop Facebook group and he seems to have perfected the brushless Whoop build with 07xx motors. Someone should look him up on Facebook and invite him to join this forum.
Here is one of his 1s 0703 12000kv brushless Whoop flight videos indoors. Crazy fast as hell!!


#11

@MidnightQuads Looks pretty cool. Can’t wait to see some flight videos!

@jayodas Damn that thing is fast. I wonder if he was flying in transition mode or full acro.


#12

Are you a member of the official Tiny Whoop Facebook group? Look him up there and invite him over!


#13

I looked up one of Steven Merrell’s FB posts and he gave the specs for a build that he says is too fast for indoor flying and below is his flight video flying it outdoors.
-Rakon brushless whoop frame
-luminier pepperfish combo (Mine is broken I suggest getting the furious fpv 4n1 and then use the luminier fc)
-boldclash 15000kv 0703
-1s nitro nectar 250mah.
-Rakon tri’s 1mm
-tinywhoop canopy
-fx900 aio


#14

That looks close to the build I was thinking of making.


#15

You know you really can’t tell from a video but it doesn’t seem to blow away a brushed whoop - performance looks very similar to mmw 716’s or the new 617’s. Maybe with hands on the sticks there is more reserve in the tank to be called upon. I’ll just have to join in and build one to judge for myself.


#16

That’s pretty much exactly what I was thinking, I switched back and forth between those videos and the Velcro/alienwhoop/snow-whoop videos and they look very similar.
Potentially because they’re all using the same battery, and that pack size can only cough up so many amps. Then it comes down to motor efficiency and craft weight (and then aero).

All in all I’m curious what y’all find out.


#17

I can add to this with the 1103 1s/2s comparisons…
I got a 1s/2s daily flier… Its the same set-up
The TinyFish project
TF FC
PF 4in1 ESCs
1103 10k RaceStar
5v Pololu for camera only
Tx03
I run this on 1s and 2s… On 1s its flys like 35% maybe 40% better than brushed… Meaning more thrust, top end speed, n punch outs…

On 2s its just a beast all around and blows the 1s out the park… So naturally I run it on 1s first to get in my groove. Then rock the 2s from there on out…

I use the micromotor mylipo 480mAh 40/80c 1s
Nano-Tech 300mAh 45/90c 2s
Also 4got to add I only see and feel the difference on the 1s battery compared to the brushed is with the Parrot RS Props 66m…


#18

@Dnex1 Thanks for the comparison.

So would you say that it is flat or indoors and feels decently locked in so you can fly in spaces you could fly your whoop, like between chair legs and around tight hallways etc?

I assume it’s unducted, but with prop guard, since you said you are following the TF build. How’s the noise level compared to your whoop using the Parot RS 66mm props?

Also, how is the TInyFish FC? I heard that it spazzes out on 1S when your voltage drops too low.


#19

No spazzing on mines… Its more locked in and safer for indoors with 56mm props… With those props its feels more like a brushed 8.5mm build with extra thrust when needed… So I would have to say 66mm are great for out doors while the 56mm are perfect for inside… But this is just my opinion. I dont do ducts on any of my builds rather i fly indoors or out… As for noise level compared to a whoop I can’t. Don’t own any. But compared to my 8.5mm micro h… I would say on 1s about the same maybe like MMW insanes… 2s they scream.


#20

Cool! So maybe 1103 may be better for an indoor whoop from a reliability standpoint compared to the 07xx motors, which really don’t seem up to par yet.