Props for 6384/74 motors no shaft

Dear All,

anyone knows where we can get a profesional propeler for outrunner 6384/74 motors (so no shaft and 4 screws) . Indeed there is EML shop + 3d printed from design from this forum

any other shops we can get ? thanks

You could also print one in esun pla+, I‘ve had good results with Volkers prop: 6384 3d printed propeller - #2 by leachim

Or get a shaft maschined from aluminium and use a Flite prop, works well with 63100.

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You can buy Flite Propeller | Fliteboard™ eFoil Europe
and print an adapter.
I print it in two parts.

It is maybe not the best design, but it works.
You need a longer shaft though and an internal thread in the shaft:


Made an adapter for FR prop. Used stainless steel bolt and 3d printed hub filled with epoxy. Used PLA+ with 30% infill. Bolt is glued in with epoxy. Did not want to use shaft pin, used 2 set screws instead.

Used it for 3 sessions so far. Love this prop.


Did the same two weeks ago, works fine too.


the fr is only pressed against the cone and is therefore non-rotatable. Im using an 6384 and Fr 7

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thanks for sharing , but I m using a 6384 with cut shaft so only the 4 screws are available !!

The adapter is attached with 4 screws to the 6384, the adapter holds a m8 x 50 for the Prop axle.

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Does it have enough power to drive the 3 blade 7” FR prop? What max rpm do you get? Motor KV, number of S?

120kv 12s, works fine.

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A 6384 motor would have no issue whatosever driving a 150mm 6" or 7" prop (and maybe even above).
What matters the more is the torque, and and outrunner has a torque to weight ratio higher than most types of inrunner.

I run a Flite prop on a 63100, was just curious because the 6384 is smaller and the 3 blade FR has a rather big blade surface. Good to have a metr log to compare. Consumtpion @ the same speed is around the same (although I would have to compare it on the same system). Max speed of 63100 and Flite is probably higher, as the Flite prop has more pitch. I might try a 2 blade 7” FR on the 63100, maybe it is a little bit more efficient.

Here is a log with @V_S Prop, its almost the same consumption as the Fr 7.

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I thought 6384 120kv limited to 36v, it supported 48v (12s)?

The limit for motor voltage is not what the chinese spec says, this is most often a jumble and mix of unrelated values.

The important thing is to maintain rpm (kV*voltage) to be below the max rpm. To get a ballpark figure for the common chinese outrunners i normally estimate a max erpm of 56000 in order to limit eddy current losses and heating.

An example:
Erpm is rpm*polepairs so if the motor is 12slots 10poles the max rpm will be 56000/5=11200

For a 12 slot 14poles (most common outrunner winding) it’s 56000/7=8000rpm

The 8000rpm figure comes from where i start noticing temperature going up when running my previous outrunners (80100) with no load so it really is a ballpark figure, not exact science. With better laminations and motor design it’s possible to use a lot higher rpm so the value can be evaluated for any outrunner by watching the power consumption and heating at full rpm no load drive.

Please note: Inrunners might explode from the centrifugal forces at high rpm so those should not be tested like this.

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I’m running the 6384 with 10s and Volkers prop with top speed 25 km/h . The motor has torque to handle a faster prop and consider to buy a FR 7 like yours. How much extra top speed did you get with the FR 7? If it is 29 vs 27 as your log suggests, thats not a lot, or do you think there is more in the tank?
Your adapter looks very nice and since I am crap at 3D CAD, I would be very grateful if you could share the STL file.

hello bbe, my highest speed (12s) so far was 32, i think there is more in it. Here is the link to the prop adapter. fr_adapter_63xx.stl - Google Drive


Thanks Riversurfer!
I’ve ordered a FR 7 so it’s gonna be interesting to see how it compares to the V_S. A 3-blade should be less efficient than a 2-blade, but the alu-prop should have less losses than the plastic prop, so hopefully about the same (which your logs suggests) and with some extra speed, and of course robustness.
6384 is such an amazing motor for the price and its good to have adapters for commercial efoil props, which usually is for the 6516x inrunners.

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Here is my adaptator for a Flite board prop on 63xx outrunner motor with no axis.
It is not perfect and i think the two screws are a bit overkill and add weight. Two pieces of hard plastic would probably be enough


Got my FR 7" prop. It is undoubtly very high quality, but not sure it will work better than the VS prop on the 6384 for me at 100kg, in terms of higher top speed and at least equal efficiency. Ideally the 2 blade version would have been better, but was sold out. Comparing the blade area, the FR is so much bigger, and the weight including @Riversurfer adapter (which fits perfect!) and screws, is 300 vs 70g. My lake is frozen over now, so I cant test it until spring, but I have some doubts if it will be a good match. It will for sure draw much more current at startup, have a more balanced and quiet flow, but since it is meant for bigger motors and speeds up to 45-50km/h, I have a feeling that the overall performance will be less on a 6384, unless going flat out at 30+ km/h.
My biggest concern is the knife sharp blades, that makes it far more dangerous than VS prop, and a prop guard is needed to feel safe. Although little chance of htting prop while spinning, touching this prop in a crash WILL cause injury, spinning or not. Adding a prop guard wilI add drag to lessen the point of using this prop, so dont see this as an option.
Since I bought it I will at least test it once and if it works fine with speed/fuel I will keep it, but most certainly blunt the edges, which I guess is only beneficial for high speeds.

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