sorry missed that. I weigh 183 pounds = 83kg
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Who exactly can measure the turns on the output shaft during the movement (the shaft is loaded)? What is the current and voltage? What is the gear ratio in the gearbox? Which propeller was used? Does anyone have this information?
I would like to make a planetary gearbox. The first version of the planetary gearbox was designed, but it turned out to be incorrect due to incorrect initial parameters (32000 -> 2000 rpm = gear ratio 16: 1, two-stage reducer). I would like to know more accurate data under load.
Hi,
I am quite new to this topic, but I got experience with outrunners, ESC and Lipos from quadcoper building and flying.
You guys surely all heard of the VESC. If not, I would give it a shot. I has the VESC-Tool where you can adjust everything ( current drawn battery, current motor side, max rpm, speed up/slow down curves, fail safe and custom scripts e.g. for the controller or maybe a gyro-balancing support…)
It can do 50-60A continuously and up to 120A brust, but I read about people with water cooling working with 160A for ~0.5s. So I guess for me (~65kg / 145lbs) it should be enough.
Also almost all outrunners use delta wiring (how the pases are connected to the poles), I don’t know about the SSS motor, but if it also uses delta, you could easily change it to star winding and reduce the KV by a factor of SQRT(3) (=~1.7). So the 360KV SSS would have about 200KV then, times 44V (@12s) equals 9200rpm no load, which should be about the 7000-8000rpm load for the aliexpress ducted prop.
Voila direct drive with same motor.
It is explained at the VESC page of Benjamin Vedder, with a lot more information about batteries and motor, quite a lot and good information I guess: http://vedder.se/2014/10/chosing-the-right-bldc-motor-and-battery-setup-for-an-electric-skateboard/
So, did anyone already receive the SSS 360KV motor and can tell something about the internal wiring?
Or if there is any mistake in my conclusions please feel free to tell me early enough 
Best,
Chris
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I agree with you. I think that lifespan of gearbox and motor, as well as simplicity and total cost should be driving the design. 1kg difference in the system (battery or motor) is quite secondary when compared to the user weight. I mean, it is the weight of a wetsuit.
What is the best guess on the motor/ESC requirements for a direct drive system?
Did anybody consider a timing belt reduction system? It would come with some big design constrains (a big step away from a single tube) but it might increase lifespan (and serviceability)
Best
Giovanni
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Yes I have been thinking belts too. Works reliable and simple on the esk8, right? Why not here. Maybe something like like this. Or without belt gear-on-gear which would be less drag. What does everyone think? Worth trying?
10 Likes
Guys we are using impeller jet since the early stage and reduced rpm prop as well.
Both have advantages and disadvantages…
Impeller Jet we use is 82mm. See https://scontent-frt3-1.xx.fbcdn.net/v/t1.0-9/22279803_123134015061367_2393120729858456509_n.jpg?oh=24898d5715ac90c726834984c70197cd&oe=5A6F1E64
But above assumptions are not correct, we draw much higher values…About 3kw is realistic. Brings problems that these rc-toy parts are at their limit, so you need more expensive parts esp. ESC a.so. But you can reach higher speeds and more safe construction…
So the way pacificmeister and Nicolai do it is I would say more efficient and a bit cheaper… If you have enough battery and able to spend more on more expensive components then impeller jet makes sense;-)
Cheers
Jay
Elevate e-Foil Upgrade Kit
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That design would have a great gyro effect on helping keep balance for pitch 
yeah, which comes along with a huge amount of drag.
Has anyone considered just having a shaft inside the mast and bevel gears at the mast-fuselage connection?
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Hello Builders,
I am very new to this forum and since I am still in the “Idea-Collecting-Phase”, I like to start with a question.
Did anyone think about “magnetic coupling” as an alternative to the commonly used method for shaft sealing?
Would be very curious to see if such a system could cope with the required rpm/torque.
I found a very interesting and simple setup designed for RC submarines in a different forum:
“https://www.rcgroups.com/forums/showthread.php?1332679-Thrusters-types”
Regards
Stephan
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Hi Stephan
I had a think about it. I work in the water treatment industry and we use magnetic coupled pumps to transfer corrosive chemicals between tanks. The problem is that these pumps are generally about 3 to 5 times more expensive than a standard pump with shaft seals. For the e-foil application you can get a couple of shaft seals for around $10. Depending on the strength of the magnets I’d imagine they would be able to cope with torque as we pump some quite viscous liquids at reasonably high flow rates.
I think this would be more useful however for an RC submarine or ROV as the pressure at the depths they operate at can be rather high and it would eliminate water from outside leaking through the seal. With the e foil I don’t think this will be too much of a problem as it operates just below the surface.
Anyway just my thoughts though.
Cheers
Ben
It will work. Onean use it in theirs Carver.
Hi Luke, I asked for lower KV at TFL HOBBY.
Answer: Technically not possible.
Yes they magnetic couplers should work, I actually was reading about them yesterday and watch a few youtube videos on them. If you find a small one we could use please share a link I’m interested in testing it out.
ya for sure, just like the gyro aspect, not a fan of belts.
I think I will give it a try. Thank you for your thoughts! My goal is to seal the Motor permanently and keep the system as maintenance free as possible. I’ll keep you updated.
Thank you Mike for asking. Any idea why it’s not possible? So now we have to wait for alienpowersystem.com
and see what the have to offer.
As for magnetic coupling I found this some time ago Magnetic Coupling Supplier - Magnets By HSMAG
@pacificmeister cool design with a belt! I was thinking about similar solution but I plan to bulid esurfbord more than a efoil because it has less problems to solve. Like this one https://www.youtube.com/watch?v=oUuA-0vBQ-A&index=1&list=LLzo5HzZQlfXVW73fE3RrGfw
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I found this site based in the UK. DST Standard | UK Flowtechnik Ltd
I got a quote from them for the 45mm dia magnetic coupling. Listed below
DST45-8 Magnetic Coupling with encapsulated magnets
- 8Nm; St.st Construction (1.4571) & Samarium Colbalt
Magnets (Sm2Co17) - Rated to 25 Bar: £394.20
This is only rated for 8Nm of torque however. The next size up 60mm dia is rated for 22Nm, it may be enough I’m not sure though as I haven’t done any testing myself yet.
Cheers
2 Likes
Ok, I just read the 360KV version has a 10Y wiring. Already star configuration. So never mind.
But I found this one: https://www.ebay.com/itm/Outrunner-Brushless-Motor-83110-WaterCooled-7Kw-for-Electric-Surfboard-Foils-/263261458688?hash=item3d4b9b1100:g:yocAAOSwsWpZ4Oou
Ok, it is 80mm diameter, but then without gearbox.
Did anyone already tried it?
1 Like