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HexTronik 24g 1300kv Motor Questions

hexig

Junior Member
#1
Hi all; long time lurker, first time poster here :cool:

Watching the FliteTest channel on YouTube got me really interested in Quadcopters, to the point where I'm now looking into building one for myself. I'm putting together a parts list loosely based on the build articles and parts suggestions for the Anycopter quad and the H quad here on FliteTest. I've found that HobbyKing has a ton of parts, but I've found many instances on their site where product information is simply non-existent.

I'm looking at these motors (hexTronik 24g 1300kv), but can't find any information about the shaft size. I'm guessing they're either 3mm or 3.175mm, but I don't really feel like placing an order based on a guess. I'd like to know so I can buy the right size prop adapters.

Does anyone know the shaft size on these motors?

Also, being noobish, I'm wondering how much of a difference prop pitch is going to have on performance/power draw for these motors. The HobbyKing page recommends 8x3.8 props, while FliteTest seems to like 8x4.5.

Will this small difference in prop pitch make much of a difference on these motors?

Thanks for your help!!
 
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xuzme720

Dedicated foam bender
Mentor
#2
Higher pitch will mean more lift but also more amp draw. I haven't used those motors myself, so anything I tell you on shaft size will also be a guess...
 

eagle4

New member
#3
they have a 3mm shaft

as for the prop sizes, not sure about the power draw, but it should still be within reasonable limits, you'll just find with the 4.5 props you'll have a ton more trust.
 

Craftydan

Hostage Taker of Quads
Moderator
Mentor
#5
Pick up a pack of 9x4.7s while you're at it. It's pushing the 7A limit of that motor at WOT (wide open throttle) -- I know, I've tested it-- but a well sized quad runs around 1/2 throttle. The motor will get warm but shouldn't overheat.

and be prepared to buy a lot of props . . . because with quads, you will break a lot of props.
 

jhitesma

Some guy in the desert
Mentor
#6
I've only run the 8x4.5 props on my quad with the 24g 1300kv motors. At full throttle it hits 28.4A which works out to 7.1a per motor. But that's the peek draw I saw and it never sustained at that amperage.
 
#7
Its a 3mm shaft, DO NOT buy these http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=5666 i used them on the motor you are looking at and they were no good at all. that set screw does nothing, i was screwing it back in everytime i landed... and thats if the propeller didnt fall of during flight!!

I went out and bought the other type that doesnt require that setscrew. http://hobbyking.com/hobbyking/store/__5677__Prop_adapter_to_suit_3_0mm_motor_shaft_collet_.html is what you want

I got some 3mm ones, dont know if a 3.175 will change anything...


besides that, i'm new too the hobby too and did my first quad which i finished this week!!

here i the thread you could be interested in: http://forum.flitetest.com/showthread.php?6423-New-to-the-hobby-and-need-help-for-a-tricopter

Someone posted this very usfull link: http://flitetest.com/authors/eluminerRC

I did that exact same build but with Hextronic 24g motors and multistar 10amp ESC's. I really think that his videos are the best way to start off, and do things correctly.

oh and i use these: http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=36342 for propellers, i broke 4 on first day of flying =P
 
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Craftydan

Hostage Taker of Quads
Moderator
Mentor
#8
I've only run the 8x4.5 props on my quad with the 24g 1300kv motors. At full throttle it hits 28.4A which works out to 7.1a per motor. But that's the peek draw I saw and it never sustained at that amperage.
Yeah, a 9" will be over the 7A max by a healthy margin at WOT, but multi's just don't stay at WOT for more than a brief climb or a sudden stop. In fixed wings people talk about only brief busts of WOT, but their "brief" means 30 seconds -- on my quad if I gave it 30s sustained WOT, it would be a tiny speck in the sky and almost unflyable from the ground. in most cases it's 2-3 seconds. I wouldn't run a fixed wing using a 9" prop on this motor with 3S . . .

<he says as he straps a 9x4.7 to the prop saver on a profile foamy> What? This is 2S and the motor isn't getting hot!

All that said, the 9x4.7 will exceed the currrent limit for the motor at WOT, so if you opt for it, regularly monitor the motor temps until you're comfortable it's Ok -- while you're testing land every other minute or so (you'll be doing that anyways), and feel the motor. They should get warm, but not hot.

BTW, +1 for Feista's comment. The collet adaptors are *far* superior to the grub screws -- the grub screws will work, but you've got to crank down so hard it's deforming the hardened shaft . . . and twisting the key and striping the hex socket in the screw. The collets go on easier and stay on better, but *ALWAYS* preflight to make sure they're tight and add locktite to anything that has threads.

Another warning, though, don't let wet locktite touch the props -- the solvent attacks the plastic. put it on the thread first, let it fully dry, then install the prop and nut.
 

Craftydan

Hostage Taker of Quads
Moderator
Mentor
#10
Need is a relitve term.


We don't NEED to use loctite on the prop shaft mounts, but It doesn't hurt and will make for fewer bad findings in preflight.

We *NEED* to get into the habit of preflighting any multirotor to make sure nothing is loose or about to come loose, so it doesn't happen in the air.

Airframes (fixed wing or rotorcraft) fly all the time without loctite or locking nuts. Airframes fly all the time without preflighting. IMO, The ones that don't do either will fall out of the sky from mechanical failure *far* more often, and the ones that do both will stay in the air with far more reliability.

IMO, a mechanical failure due to poor maintanince is pilot error, and it's one source of pilot error any pilot can virtualy eliminate without requiring a lot of time in the air.

</soapbox>
 

jhitesma

Some guy in the desert
Mentor
#13
FWIW - I have run the 9x4.5 props on my 24g motors with a 3s in planes and have yet to burn one up. But that was with no full throttle and only because I forgot that I had the 9" on and was out of 2s's with a charge on them ;)

Motor was pretty warm but not untouchably hot. I didn't have my thermometer with me to say just how how it was.
 

hexig

Junior Member
#14
BTW, +1 for Feista's comment. The collet adaptors are *far* superior to the grub screws -- the grub screws will work, but you've got to crank down so hard it's deforming the hardened shaft . . . and twisting the key and striping the hex socket in the screw. The collets go on easier and stay on better, but *ALWAYS* preflight to make sure they're tight and add locktite to anything that has threads.
Wait... I can use the collet adapters on a regular "smooth" motor shaft? For some reason I thought the shaft on the motor has to be special in order to accept the collet adapter...
 

xuzme720

Dedicated foam bender
Mentor
#15
Nope it just needs to be the right size to fit the shafts, or you have to get the right size collet adaptors. It depends on what you have already.