Electric Surf Board

Boats, Jet Skis, Kayaks etc., including hovercrafts
chris_kline   100 W

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Re: Electric Surf Board

Post by chris_kline » Oct 20 2019 12:43pm

srn wrote:
Oct 20 2019 5:56am
I have a 3D printed steel impeller. Ordered it at i.materialise.com
There you can upload your file and instantly get a price.

The print quality is impressive
great thanks, i will try them.

fabianpusch   1 W

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Re: Electric Surf Board

Post by fabianpusch » Oct 21 2019 1:21pm

One question:
When I have printed something from metal there was a shrinkage.
I have checked i.materialise.com what was the shrinkage there?
I think this is still something unknown with steel?

srn   10 W

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Re: Electric Surf Board

Post by srn » Oct 23 2019 3:46am

fabianpusch wrote:
Oct 21 2019 1:21pm
One question:
When I have printed something from metal there was a shrinkage.
I have checked i.materialise.com what was the shrinkage there?
I think this is still something unknown with steel?
Hello,

i.materialise writes:
As the production of your steel model involves a thermal step, shrinkage is something you should take into account. We advise you to scale up the desired design by 2% for designs where X, Y or Z is below 70 mm and 3% for models which are larger. This larger scale will compensate for the shrinkage and as a result, the dimensional accuracy will be ±1%. This is an indication but it cannot be guaranteed
I scaled my impeller accordingly and got a good result.
For the shaft I made the hole smaller then needed and drilled it afterwards to the right size including screw thread.

chris_kline   100 W

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Re: Electric Surf Board

Post by chris_kline » Oct 23 2019 9:52am

hi guys
i made a full video, jetsurfing at the beach.
https://www.youtube.com/watch?v=hpW3-ppHwgc&t=2s

fabianpusch   1 W

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Re: Electric Surf Board

Post by fabianpusch » Oct 23 2019 1:28pm

Once again, big congrats from my side.
Good job, nice ride, cool video and a nice spot.
I would like to talk to you about your jetpump.
If it would be ok for you :D

chris_kline   100 W

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Re: Electric Surf Board

Post by chris_kline » Oct 23 2019 2:26pm

fabianpusch wrote:
Oct 23 2019 1:28pm
Once again, big congrats from my side.
Good job, nice ride, cool video and a nice spot.
I would like to talk to you about your jetpump.
If it would be ok for you :D
thanks fabian.
feels good to finally have a working board.
sure, what would you like to know?

fabianpusch   1 W

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Re: Electric Surf Board

Post by fabianpusch » Oct 24 2019 12:06pm

I am trying to build up a pump. The problem is the CFD actually...I am not sure where to start.
Second, I have already tried to print one in metal.
Big fail because of the supports, needed to build up the impeller.
Which diameter are you using?
What are the main specs?
Maybe it is possible to give you a short call instead of trying to write a proper English 😄

chris_kline   100 W

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Re: Electric Surf Board

Post by chris_kline » Oct 25 2019 6:01am

fabianpusch wrote:
Oct 24 2019 12:06pm
I am trying to build up a pump. The problem is the CFD actually...I am not sure where to start.
Second, I have already tried to print one in metal.
Big fail because of the supports, needed to build up the impeller.
Which diameter are you using?
What are the main specs?
Maybe it is possible to give you a short call instead of trying to write a proper English 😄
tbh my skill with CFD is basic/beginner, i can do a simulation on something simple like a tube, or a fin, but to do an entire jetpump, with moving parts etc is well beyond me.

to design my pump i used simple 2d calculations for torque, flow volume, inertia etc. which gave me perfect thrust and engine loading from the start. but what it didnt account for, was cavitation which has been a bit of a headache trying to solve. esp as seawater cavitates more easily than freshwater.

the way i got around that was just by machining in total 4 different moulds for props, each with different pitch on the blades, to keep max torque and thrust the same, each prop has a different size nozzle.
the design i ended up on is 87mm diameter, 80mm pitch, and a 50mm nozzle. the inlet port of the pump is a little larger in cross sectional area to cut down on cavitation and accelerate the water into the pump, a little bit of positiove inlet pressure from forward movement helps to cut down on cavitation.

if you like i can send you my 3d models for you to look at.
or i can give you my phone number by PM if you like. let me know

fabianpusch   1 W

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Re: Electric Surf Board

Post by fabianpusch » Oct 25 2019 7:01am

Hi Chris
Both would be fine for me and a big help.
Actually I have an offer from China 1200$ for an Impeller because of the complex geometry (CNC).
Maybe I am actually doing an overengineered solution.
I am really interested in looking at your files.
My private E-Mail
fabian.pusch@googlemail.com
I will have a look at your data and give you a call.
When would be the best time for you?
Thanks a lot
Fabian

chris_kline   100 W

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Re: Electric Surf Board

Post by chris_kline » Oct 25 2019 10:46am

no probs.
what format is good for you?
ill find the drawings and compile them together for you over the weekend

fabianpusch   1 W

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Re: Electric Surf Board

Post by fabianpusch » Oct 25 2019 11:00am

Perfect, I have Catia V5, so Stl., Step, Iges.,...nearly any format.
Please, if it is ok for you, send me your number.
I would like to talk to you....maybe we can go one step further...
Have a nice Friday evening
Fabian

fabianpusch   1 W

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Re: Electric Surf Board

Post by fabianpusch » Nov 01 2019 6:01am

Hi Chris
Any news?
Did you already sent an email?
Cheers Fabian

chris_kline   100 W

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Re: Electric Surf Board

Post by chris_kline » Nov 04 2019 7:57am

fabianpusch wrote:
Nov 01 2019 6:01am
Hi Chris
Any news?
Did you already sent an email?
Cheers Fabian
hi fabian.
sorry mate, ive been real busy with work etc the last week.
ill see if i can get it to you by tomorrow

pepe pisa   10 µW

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Re: Electric Surf Board

Post by pepe pisa » Nov 04 2019 11:53am

Hello guys, then nobody who has a lampuga boost ??

fabianpusch   1 W

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Re: Electric Surf Board

Post by fabianpusch » Nov 05 2019 4:47pm

No sorry...I have my home made one.

fabianpusch   1 W

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Re: Electric Surf Board

Post by fabianpusch » Nov 06 2019 1:39am

chris_kline wrote:
Nov 04 2019 7:57am
fabianpusch wrote:
Nov 01 2019 6:01am
Hi Chris
Any news?
Did you already sent an email?
Cheers Fabian
hi fabian.
sorry mate, ive been real busy with work etc the last week.
ill see if i can get it to you by tomorrow
Sorry for writing an additional message 😜

chris_kline   100 W

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Re: Electric Surf Board

Post by chris_kline » Nov 06 2019 4:57am

fabianpusch wrote:
Nov 06 2019 1:39am
chris_kline wrote:
Nov 04 2019 7:57am
fabianpusch wrote:
Nov 01 2019 6:01am
Hi Chris
Any news?
Did you already sent an email?
Cheers Fabian
hi fabian.
sorry mate, ive been real busy with work etc the last week.
ill see if i can get it to you by tomorrow
Sorry for writing an additional message 😜
drawings sent

fabianpusch   1 W

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Re: Electric Surf Board

Post by fabianpusch » Nov 07 2019 11:02am

Yes you are right and a lot of E-Mails too.
Thank you, will follow up with one tomorrow 😃

jetsurfer   1 µW

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Re: Electric Surf Board

Post by jetsurfer » Nov 13 2019 12:02am

Hi All

I'm looking for a 100mm or so Jetpump to build my DIY jetboard

Below is Motor, ESC, Battery setup I'm planning to use what do you think I should use for the jet pump?

Proposed Materials

Batteries 15 (Maybe 16s) x 60ah 3.2v Lipo4 cells 3.3KW - $980 https://www.aliexpress.com/item/4000067 ... 2e0eewN5LL

Waterproof ESC Seal 300A 60V ESC Motor controller - $376
https://www.aliexpress.com/item/4000092 ... 2a06jcyBBa

Water Cooling Motor 9097 150KV 18KW 24HP - $914
https://www.aliexpress.com/item/4000073 ... 88edAolPzs

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methods   10 GW

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Re: Electric Surf Board

Post by methods » Nov 13 2019 3:10pm

Epic project!

You are literally "Living my Dream" right now. Thanks for posting pics. . . that is about what I pictured... but you got a lot farther into the project over the years.

... I can tell that I am going to need some support that exceeds my current fab skills/resources.

- It has got to be light
- It has got to be quiet
- It cant eat my knees :mrgreen:

I will post later when I get the trolling lower end zip-tied to the old Boogie Board. One thing I have found is:

The small props scream like hell to get the thrust I need. . . so I am going "Big Prop"

-methods
Increasing battery voltage and controller current limit will result in a non linear experience

pepe pisa   10 µW

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Re: Electric Surf Board

Post by pepe pisa » Dec 27 2019 6:50am


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methods   10 GW

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Re: Electric Surf Board

Post by methods » Dec 27 2019 12:51pm

Hardcore video.
Lots of hints in there.

I am still visiting the "Marine Flea-market" down at the harbor waiting to find a set of pull-down thrusters. It is looking like anything that comes off of a power boat (that actually puts out some useful thrust) is very heavy and industrial. Makes sense - as in the power boating around here (fishing, crabbing) weight seems to be of little concern. It seems that the pull-down gear is focused on low cost and reliability, so large castings and standard windings.

The... sailing gear... is actually the polar opposite. Carbon fiber toilet seats and all that "save a gram" stuff going on.

I imagine...
That some rich guy...
No doubt bought a $7500 piece of gear at some point for his $300k race boat...

...And it is only a matter of time until I can pick it up used gem for a few hundred bucks....

Large racing sail boats - I have seen them park... some of them no doubt have thrusters...

-methods
Increasing battery voltage and controller current limit will result in a non linear experience

chris_kline   100 W

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Re: Electric Surf Board

Post by chris_kline » Jan 08 2020 3:31pm

look at that giant external caps bank on the mgm esc.
when my caps kept blowing, mgm were telling me "its your batteries, its your motor, its everything except the ESC", and charging me stupid amounts of money to repair and replace.
turns out lampuga also had problems with the caps exploding. hence the external caps bank
Attachments
Untitled.jpg
Untitled.jpg (232.57 KiB) Viewed 1543 times

fabianpusch   1 W

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Re: Electric Surf Board

Post by fabianpusch » Jan 10 2020 6:49am

Hi Chris

Has always been the battery, the length of the cables,...
At the moment I have to additional banks and it is working.

By the way, I have bought a Jetsurf ;-)

Cheers Fabian

chris_kline   100 W

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Re: Electric Surf Board

Post by chris_kline » Jan 11 2020 7:51am

fabianpusch wrote:
Jan 10 2020 6:49am
Hi Chris

Has always been the battery, the length of the cables,...
At the moment I have to additional banks and it is working.

By the way, I have bought a Jetsurf ;-)

Cheers Fabian
awesome. which model did you get? new or second hand? how is it to ride?

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