Electric Surf Board

Boats, Jet Skis, Kayaks etc., including hovercrafts
fabianpusch   10 mW

10 mW
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Re: Electric Surf Board

Post by fabianpusch » Apr 01 2018 2:56pm

I have done some videos with me GoPro, so if there is some free time I will try to load up.
At the moment I am very busy to finish the intake area and make the electronic wiring like in the automotive industry...
I will be in Corsica for three weeks to test everything again.
What kind of battery do you use?

chris_kline   10 W

10 W
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Joined: Sep 20 2017 9:51am

Re: Electric Surf Board

Post by chris_kline » Apr 01 2018 3:01pm

i made a pack from 112 samsung q30 cells. so its a 14s 8p battery. lasts about 25 mins

do you work in the auto industry? out of curiosity what motor did you use? also are you planning to manufacture/sell the boards? looks like youve put some effort into the design work.

looking forward to seeing some vids!

fabianpusch   10 mW

10 mW
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Re: Electric Surf Board

Post by fabianpusch » Apr 01 2018 3:41pm

No it is just for fun ;-)
At the moment I am using Kokam pouch cells 14S1P.
I have worked in the automotive industry and also some years in the formular 1, that is the reason for doing everything in carbon.
My first board was finished 2013, at those days it would have been the right time to think about selling it. Today there are a lot of products on the market.
What kind of remote are you using? That is one of the last big challenges, the waterproof issue.

chris_kline   10 W

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Joined: Sep 20 2017 9:51am

Re: Electric Surf Board

Post by chris_kline » Apr 02 2018 1:11pm

fabianpusch wrote:
Apr 01 2018 3:41pm
No it is just for fun ;-)
At the moment I am using Kokam pouch cells 14S1P.
I have worked in the automotive industry and also some years in the formular 1, that is the reason for doing everything in carbon.
My first board was finished 2013, at those days it would have been the right time to think about selling it. Today there are a lot of products on the market.
What kind of remote are you using? That is one of the last big challenges, the waterproof issue.
thats cool, im also automotive industry engineering :)

i plan on designing/making a remote using some off the shelf components,linear potentiometer for trigger. machined casing, and injection mould some latex water seales/gaskets etc

chris_kline   10 W

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Re: Electric Surf Board

Post by chris_kline » Apr 02 2018 1:13pm

well i got it full speed today, heres a vid https://youtu.be/c0XDJY2NXT8

but i blew a cooling hose and the esc went into protection mode, hence i end up in the drink!

heres another vid of about 80 percent throttle https://youtu.be/d7sS6LbpJsw

fabianpusch   10 mW

10 mW
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Joined: May 28 2016 5:07am

Re: Electric Surf Board

Post by fabianpusch » Apr 02 2018 3:06pm

Yeah looks really good and a little funny.
Have you the possibility to check the speed with a GPS?
Should be something around 25-30 km/h...or?
Have you limited the rpm? From the sound it is round about 13500-14500?
Looks really good, go on with optimization :D

chris_kline   10 W

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Joined: Sep 20 2017 9:51am

Re: Electric Surf Board

Post by chris_kline » Apr 02 2018 3:54pm

yeah it looks pretty funny, but wasnt so funny when the brain freeze started.

its hard to say how fast it is, it feels real fast, but im guessing around 35 kph at full throttle, although it feels like 100kph.

ill see if i can get a gps sorted to take some speed measurements

chris_kline   10 W

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Joined: Sep 20 2017 9:51am

Re: Electric Surf Board

Post by chris_kline » Apr 02 2018 4:00pm

srn wrote:
Mar 27 2018 7:22am
chris_kline wrote:
Mar 06 2018 4:43am
hello

i didnt recveive the esc yet. mgm said it would take 3 weeks to complete, but it then took nearly 2 weeks just to get an order confirmed from them, ultra slow response via email. its now been 5 weeks since i started the process

feeling a bit frustrated
Hope that it will arrive soon.
Would like to hear your experience before I order same parts. :D
Hi srn.

so my first impressions are the mgm esc is very very good indeed. i bought the industrial version, so i dont know exactly how different it is from the modeller version. it was pretty expensive at 1100 euro. but the temperature protection works great as i found out today. extremely well manufactured piece of hardware, the software setup works great, i fully recommend it if you wanna spend the bucks.

also the lehner 7050 motor works great, i gave it some abuse today, and it looks, and smells brand new, so i would recommend this also. how is your project coming along?

srn   1 W

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Joined: Sep 21 2017 8:50am

Re: Electric Surf Board

Post by srn » Apr 04 2018 1:54am

chris_kline wrote:
Apr 02 2018 4:00pm

Hi srn.

so my first impressions are the mgm esc is very very good indeed. i bought the industrial version, so i dont know exactly how different it is from the modeller version. it was pretty expensive at 1100 euro. but the temperature protection works great as i found out today. extremely well manufactured piece of hardware, the software setup works great, i fully recommend it if you wanna spend the bucks.

also the lehner 7050 motor works great, i gave it some abuse today, and it looks, and smells brand new, so i would recommend this also. how is your project coming along?
Hello chris,

MGM was also recommending me the pro version for around 1100€. But I still think the hobby version for 700€ might be enough.

I nearly finished my drive unit with a gearing to increase the height of my drive shaft.
Next step is to install the aluminum plate into my carbon board. I am thinking whether to glue or to screw it.
driveunit1.jpg
driveunit1.jpg (87.95 KiB) Viewed 1223 times

chris_kline   10 W

10 W
Posts: 69
Joined: Sep 20 2017 9:51am

Re: Electric Surf Board

Post by chris_kline » Apr 04 2018 8:55am

srn wrote:
Apr 04 2018 1:54am
chris_kline wrote:
Apr 02 2018 4:00pm

Hi srn.

so my first impressions are the mgm esc is very very good indeed. i bought the industrial version, so i dont know exactly how different it is from the modeller version. it was pretty expensive at 1100 euro. but the temperature protection works great as i found out today. extremely well manufactured piece of hardware, the software setup works great, i fully recommend it if you wanna spend the bucks.

also the lehner 7050 motor works great, i gave it some abuse today, and it looks, and smells brand new, so i would recommend this also. how is your project coming along?
Hello chris,

MGM was also recommending me the pro version for around 1100€. But I still think the hobby version for 700€ might be enough.

I nearly finished my drive unit with a gearing to increase the height of my drive shaft.
Next step is to install the aluminum plate into my carbon board. I am thinking whether to glue or to screw it.

driveunit1.jpg
looking good, cant wait to see it all together!

toto44   100 mW

100 mW
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Joined: Sep 05 2015 5:40am

Re: Electric Surf Board

Post by toto44 » Apr 04 2018 10:00am

Printed everything, nearly ready for first testrun.
IMG_1169.JPG
IMG_1169.JPG (91.31 KiB) Viewed 1287 times
IMG_1168.JPG
IMG_1168.JPG (94.53 KiB) Viewed 1287 times

fabianpusch   10 mW

10 mW
Posts: 24
Joined: May 28 2016 5:07am

Re: Electric Surf Board

Post by fabianpusch » Apr 04 2018 11:16am

Hello
I will sell my MGM compro industrial version.
It is the 250 63V...
Reason I will use a another more or less self developed one.
It works well with the TorQstar
It has an Emergency OFF, logging, PWM input, additional water sealing and water cooling.

If interested, write a PM

Bye Fabian

PS the drivetrain looks great 😃

srn   1 W

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Joined: Sep 21 2017 8:50am

Re: Electric Surf Board

Post by srn » Apr 04 2018 1:01pm

currently integrating my drive unit
E768BF48-278D-4B49-823A-1840EAEF3310.jpeg

chris_kline   10 W

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Posts: 69
Joined: Sep 20 2017 9:51am

Re: Electric Surf Board

Post by chris_kline » Apr 04 2018 3:09pm

toto44 wrote:
Apr 04 2018 10:00am
Printed everything, nearly ready for first testrun.
IMG_1169.JPGIMG_1168.JPG
looking very slick!

chris_kline   10 W

10 W
Posts: 69
Joined: Sep 20 2017 9:51am

Re: Electric Surf Board

Post by chris_kline » Apr 04 2018 3:09pm

srn wrote:
Apr 04 2018 1:01pm
currently integrating my drive unit
E768BF48-278D-4B49-823A-1840EAEF3310.jpeg
wow, thats like a work of art!!

luca   1 µW

1 µW
Posts: 3
Joined: Jan 07 2018 10:33pm

Re: Electric Surf Board

Post by luca » Apr 05 2018 5:53pm

this is my work..
rpm under load 24.000
motor t power 5870 9 kw 12s
current 70 amp at full throttle.

sundogz from rcgroups, has designed a new impeller with overlapping blades should be exploit the motor.
wait the 3d print and making new test.
Attachments
Webp.net-resizeimage (2).jpg
Webp.net-resizeimage.jpg

Toronto e-surf   1 µW

1 µW
Posts: 1
Joined: Apr 08 2018 12:51pm

Re: Electric Surf Board

Post by Toronto e-surf » Apr 08 2018 12:58pm

I've just finished reading the whole thread, some of this stuff looks amazing. currently working on building my esurf board (pictures to come) i was scrolling around and found this, thought you guys would get a kick out of it!

http://www.dailymail.co.uk/sciencetech/ ... ments.html

fabianpusch   10 mW

10 mW
Posts: 24
Joined: May 28 2016 5:07am

Re: Electric Surf Board

Post by fabianpusch » Apr 09 2018 2:50pm

Yeah that looks really amazing.
In the endlich you have also passed a workout for your arms.
Looks really funny but heavy...

ZR38   1 µW

1 µW
Posts: 3
Joined: Apr 16 2018 6:47am

Re: Electric Surf Board

Post by ZR38 » Apr 16 2018 7:05am

Hi everybody,

I have the same waterjet project; thank you for these thread (I have almost all read) it is very interesting with some incredible designs! :)
I have a question, maybe can you help me...
I'm designing 2 waterjets (one with a 58mm impeller and one with 80mm impeller), but I have not chosen the motor yet (I will first test the 58mm version).
How can we know the maximum speed (RPM) of the impeller according to its size? a 80mm diameter impeller can not turn as fast as a 58mm (to avoid cavitation).
Is there a "rule" to know the maximum speed of an impeller? (in order to be able to deduce the "KV" of the motor)

Thank you for your help :-)

srn   1 W

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Joined: Sep 21 2017 8:50am

Re: Electric Surf Board

Post by srn » Apr 16 2018 9:48am

Hello ZR38,

there is no rule because it highly depends on impeller design.
I was reading many numbers between 8.000 and 15.000 rpm.

For my project I ordered a powerful motor (Lehner Torqstar 3) and will test my relatively small impeller (60mm) from 0 - 17.000 rpm.
Diagrams of thrust/rpm and rpm/power will show where this impeller has best efficiency. And if my motor is too bored at this rate, I have to increase impeller size.

ZR38   1 µW

1 µW
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Joined: Apr 16 2018 6:47am

Re: Electric Surf Board

Post by ZR38 » Apr 17 2018 3:20am

Hello srn,

Thank you for your answer.
I will do as you :)

For diagrams, how will you proceed? you will note the flow of the waterjet during your tests to then calculate the thrust? That's right?

srn   1 W

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Joined: Sep 21 2017 8:50am

Re: Electric Surf Board

Post by srn » Apr 17 2018 4:51am

Hello ZR38,
Good question, at the moment I think to measure the thrust a kind of spring-scale should be the best.

Frizzo   10 mW

10 mW
Posts: 32
Joined: Nov 27 2016 6:07am

Re: Electric Surf Board

Post by Frizzo » Apr 17 2018 8:25am

Would be interesting to build a flumen. So you actually could measure the impeller effency, the torque, amps, rpm and also optimize the nozzle and stator geometry.

have a look at this:

http://efoil.builders/t/home-made-flume/794

Frizzo   10 mW

10 mW
Posts: 32
Joined: Nov 27 2016 6:07am

Re: Electric Surf Board

Post by Frizzo » Apr 17 2018 8:28am

Also, I saw that you are going for a gearbox build. That's actually the way I was going too before I noticed that at that rpm range, the gearbox is going to be really really hot. Did you already think how to cool the gears?

Cheers

srn   1 W

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Re: Electric Surf Board

Post by srn » Apr 17 2018 9:22am

Frizzo wrote:
Apr 17 2018 8:28am
Also, I saw that you are going for a gearbox build. That's actually the way I was going too before I noticed that at that rpm range, the gearbox is going to be really really hot. Did you already think how to cool the gears?

Cheers
Interesting point, have not thought about this yet. My "Gearbox" are just two gears to increase the height of the shaft. I will measure the temp on the gears.

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