Electric Surf Board

Boats, Jet Skis, Kayaks etc., including hovercrafts
chris_kline
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Re: Electric Surf Board

Post by chris_kline » Feb 04, 2018 1:35 pm

well, it worked!

first test https://youtu.be/QXQUv2pck1Y

Frizzo
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Re: Electric Surf Board

Post by Frizzo » Feb 04, 2018 4:14 pm

Good job dude!
That look's AWSOME!! :D
So I'm thinking to sell my Lehner and buy your same motor.. cheaper and work well too apparently... :)

chris_kline
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Re: Electric Surf Board

Post by chris_kline » Feb 04, 2018 4:27 pm

thanks frizzo. tbh, i didnt really expect it to work so well. i mean i expected it would move forward, but it was faster than i thought, happy surprise!

i think the lehner torquestar is probably a much better motor, but this one works also.

ill have a few more full charges and try outs before i fully recommend the motor i bought, see if it burns out or not. unfortunately i got kicked of the lake i was on today after about 5 mins so didnt get to fully hammer it for a full charge.

just out of interest. does anyone know of a good explanation on rewinding a motor? im curious to learn more about getting more power or torque out of a motor. thanks

Frizzo
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Re: Electric Surf Board

Post by Frizzo » Feb 04, 2018 4:29 pm

https://www.youtube.com/watch?v=-sIVpOLYoqg

maybe this?

Also, how do you think about using this: https://www.amazon.com/gp/product/B01HI ... 0208162011

for your slippery board?

Would maybe be cheaper than pads...

chris_kline
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Re: Electric Surf Board

Post by chris_kline » Feb 04, 2018 4:47 pm

perfect thanks

as it happens, i ordered exactly that pad material just last week! the carbon is real slippery. especially when your feet are numb from the 2 degree water

Frizzo
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Re: Electric Surf Board

Post by Frizzo » Feb 04, 2018 4:52 pm

Yeah... can imagine that.
Did you take measurements of the ESC temperature and Ampere? Would be interesting to know if the ESC can really handle the 300 A.
And also see if nothink burns out :D

chris_kline
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Re: Electric Surf Board

Post by chris_kline » Feb 04, 2018 5:13 pm

i measured current when testing the jet drive in a 50 gallon drum. it was drawing about 150 amps at full load.

i didnt measure temperature of the esc or motor. but after testing it in the lake for about 5 mins on full throttle, the esc was, i would say about 45 deg c, and the motor outside was prob about 35 deg c. although the motor being an outrunner, i guess thats not really an indication of the temp of the copper windings. also the esc has a pretty chunky aluminium body/case, so i dont really know what the temps were inside.

like i said, let me thrash it on a couple full charges and ill see how it does.

chris_kline
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Re: Electric Surf Board

Post by chris_kline » Feb 04, 2018 6:29 pm

this looks like a good source of info for the how and why of rewinding motors https://www.rcgroups.com/forums/showthr ... ecks-tests

srn
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Re: Electric Surf Board

Post by srn » Feb 05, 2018 7:51 am

chris_kline wrote:
Feb 04, 2018 1:35 pm
well, it worked!

first test https://youtu.be/QXQUv2pck1Y
Hello Chris,
congratulations, it looks really good.
But be honest, I think you increased the video speed ? The waves are moving fast .. :wink:
Anyways it is visible that the board is driving fast and has good gliding ability.

chris_kline
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Re: Electric Surf Board

Post by chris_kline » Feb 05, 2018 8:31 am

thanks

although that really is the actual video speed.

ill post another one of me waving on the board, maybe that will help show the speed more clearly

chris_kline
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Re: Electric Surf Board

Post by chris_kline » Feb 05, 2018 3:13 pm

ok, so heres the very first test so you can see the film isnt sped up.
the first run i was too far back on the board so it would plane, but the last two, i got into a better position to get the board planing. once it hits the plane, it just goes!

excuse my floundering on the board like a sea otter trying to stay out of the freezing water :roll:
https://youtu.be/RKrlz6btq0E

Frizzo
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Re: Electric Surf Board

Post by Frizzo » Feb 14, 2018 2:39 pm

Chris, how is it going? Did you push the motor to its limits already?

chris_kline
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Re: Electric Surf Board

Post by chris_kline » Feb 15, 2018 9:23 am

Frizzo wrote:
Feb 14, 2018 2:39 pm
Chris, how is it going? Did you push the motor to its limits already?
yeah i pushed it, and the windings burned out after about 10 mins. i should have monitored the current and temps while using the board.

oh well. i contacted the company who makes the motor, and they are very helpful. they say they can produce a motor with more copper to keep the temps under control. but its chinese new years, and they wont be able to start production again until the 24th, then it will be probably about 2 weeks to arrive in romania. then probably a month in romanian customs office. anyway, im feeling impatient, so i just ordered a "lehner torqstar 3 7050"

i think the chinese motor would probably be fine. but my 79mm prop and 70mm pitch are a little aggressive for it. i have now redesigned the prop to be 79mm dia and 55mm pitch, and that coupled with a custom chinese motor would probably have been great. but unfortuately, thats not how it worked out for me.

for now the chinese esc is still working, and it has some kind of protection on it which is good!

srn
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Re: Electric Surf Board

Post by srn » Feb 15, 2018 12:54 pm

I want to use the same motor. How long do you have to wait for it ?

chris_kline
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Re: Electric Surf Board

Post by chris_kline » Feb 15, 2018 1:57 pm

srn wrote:
Feb 15, 2018 12:54 pm
I want to use the same motor. How long do you have to wait for it ?
which one the lehner or the chinese?

the lehner wait is 10 days after payment. plus shipping time.

the chinese motor was about the same, 10 days plus shipping. but its chinese new year, so there is a delay currently. and romanian international customs is a freaking nightmare of procrastination and apathy.

honestly i think the chinese motor is pretty good, and for 150 dollars, its well worth it. i think i just gave it a little too much of a hard time with my big prop. i think your 60mm prop would be perfect with it.

srn
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Re: Electric Surf Board

Post by srn » Feb 16, 2018 3:08 am

I wanted to buy the Torqstar but was also oftentimes thinking about Alienpowersystems 83110 with 7kw.

Maybe 7kw is enough to start with ..

just dont want to buy twice.

chris_kline
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Re: Electric Surf Board

Post by chris_kline » Feb 16, 2018 3:30 am

well looking at the alien power system 83100. that actually is the chinese motor i had.

srn
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Re: Electric Surf Board

Post by srn » Feb 16, 2018 4:23 am

yes they are all same ..
but you burned it, so maybe I should also go for the Lehner directly.

1000€ vs 180€ :roll:

chris_kline
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Re: Electric Surf Board

Post by chris_kline » Feb 16, 2018 5:21 am

yeah, but my prop is big, and aggressive pitch.

this guy has a torqstar 2 for sale still. he wanted 700 euro for it, https://endless-sphere.com/forums/membe ... le&u=14877.

i decided to spend the extra $ on the torqstar 3.

i tried to rewind my chinese motor, but it kept grounding out the body after a minutes use. after 8 times i gave up. i think maybe the magnet wire i bought locally didnt like being wound so tightly on a compact motor, and probably my technique wasn't all that.

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Bazaki
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Re: Electric Surf Board

Post by Bazaki » Feb 18, 2018 3:57 am


srn
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Re: Electric Surf Board

Post by srn » Feb 19, 2018 2:31 am

chris_kline wrote:
Feb 16, 2018 3:30 am
well looking at the alien power system 83100. that actually is the chinese motor i had.
Do you want to use same ESC for the Torqstar ?

chris_kline
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Re: Electric Surf Board

Post by chris_kline » Feb 19, 2018 6:21 am

yep.

according to the manufacturer, the esc is good for 300A cont, and 1000A burst. i kinda doubt its really gonna live up to that, but if it gets even halfway close to that it should be ok

the lehner motor is rated for like 200A cont

this time im gonna wire up a temp sensor to the stator/windings, and also an amp meter so i can monitor the thing, and not blow it up again

https://www.ebay.co.uk/itm/056-4-Digit- ... 0706.m4781

Frizzo
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Re: Electric Surf Board

Post by Frizzo » Feb 20, 2018 9:03 am

Do you also need to change your battery pack or can it deliver 200 A cont.?

chris_kline
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Re: Electric Surf Board

Post by chris_kline » Feb 20, 2018 9:48 am

no, my battery pack is rated at 160A cont. but my old motor was drawing 160A peak when full throttle on the jetdrive.
i dont really expect that to change much, since im using the same size prop, and the motor will have the same number of windings

srn
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Re: Electric Surf Board

Post by srn » Mar 06, 2018 2:55 am

chris_kline wrote:
Feb 20, 2018 9:48 am
no, my battery pack is rated at 160A cont. but my old motor was drawing 160A peak when full throttle on the jetdrive.
i dont really expect that to change much, since im using the same size prop, and the motor will have the same number of windings
Hello Chris,
Any updates with the new Torqstar ? I am excited to read about your comparison to the chinese motor.

Best regards

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