Divided by pole pairs (3), guessing it is erpm not rpm, so it makes 100kv
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You need to set the correct pole numbers in the logger to get the correct RPM data. It appears you have the poles set to 2.
If I remember correctly this motor has 6 poles so the RPM data needs to be divided by 3 still.
Therefore Max RPM in the graphs would be 12768/3 = 4256.
Considering the voltage is 42.4V I’d say your motor is more than 100Kv.
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Isn‘t there a need for a „thrust bearing“ in this setup?
I only feel a little cavitation when start, the rest of the ride works well.
This is the video with 140mm prop 100kv motor
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Fron The Graph above it looks your avarege current is around 70-80A.
Do you have comparison to your geared setup?
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This looks like they are simply labelling the 120Kv motor as 100Kv!
At that RPM and assuming it is actually 120KV it would be giving an efficiency of around 88% which would be about right.
It will be very interesting to see what speeds you are reaching with this prop and whether it can handle 6" and 7" props well.
What OS are you using on your PC for downloading the logs? I had issues with my swordfish 300A, although I’m convinced it was defective anyway as it would only start up the first time and then not again until I powercycled it.
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windows 7, this was my first test with 140mm I will update data gps next rides :guiño:
I use the same prop with less diameter (120mm) in my gearded propulsion tp power reisenauer with aprox 60-70A average
thank you @virus for the numbers, i used swordfish last year:
- voltage recording can be off by 2-3v
- thr and remote need to be set at 99,9% if we want to use the numbers
- rpm off load: battery voltage (checked) x thr (100%) =erpm/nb of poles , then you find your kv or the nb of poles…
- max rpm should drop on load by 20% at least
- current measured is probably current motor, so it is hard to know and compare WH since most measures here are made on the battery side
anyway this set up works
Of course, these data are only a complement to compare with my experience in the water. I’ve tried many propulsions and I can feel if this works with respect to the previous tests. And now I’m trying to get the most efficient prop with this 100kv motor. First with different diameter measurements and then I will try other pitch props, between 120-140mm diam. is good with this yamaha prop. It can lift 120kg of weight easy, me and my daughter weight 120kg and is rerally fast, I will test more things but I’m very happy with the results at now and people here can be tranquility to make one without problems.
People know the most difficult thing is to remove the water in efoil system and this waterproof motor is the solution, ok? You just need to make a good enclosure for your electronics and enjoy.
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Do you have a VESC capable of running 12S? As it is a PMSM it should run better in FOC would be interesting to compare
Yes, I have the Nick VESC and Maytech vesc6 200A but I need a few days. I have a lot of work in this moment.
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hello Virus,
For me, the diameter Yamaha prop 2HP is 184 mm (7 1/4), and you talk about diameter 140 mm (or less). Can you explain ?
Thank you
Maybe he made it smaller or he means pitch 140mm. I know the pitch is 138mm.
If you look closely at the pic you can see it’s been cut down to 140mm
$760 for 195kv.
https://www.aliexpress.com/item/33055746076.html?spm=2114.12010612.8148356.4.1119435csHKnRI
Do you have to contact them directly for custom 100kv motor? and how much?
I don’t think the pitch is changing, becaus the angles of the blades are still the same. The prop wil turn faster because there is less resistance from the prop tips, but there will also be less thrust at the same rpm and there for more slip. But it could be better for your motor to not overload it.