Paul Turbine Jet Man

Hello everyone. I need your help / knowledge if you don't mind.
it would seem by the size of this thread you guys have plenty of experience with rc water jets.
if you don't like my post please tell me where i can put it.




Here we go………..( keep in mind I’m not a complete muppet. I know what I’m doing with electronics , lipos and speed controllers I just don’t have enough knowledge at the moment about small water jet systems)


I want to install micro jet systems into a surfboard as a project to have a powered electric surfboard.

I know it sounds stupid but please bear with me.

Keeping in mind that the surfboard + my weight will be about 95 KG and it will never go more than say 8 km/ph if that.

But that’s not a problem….. I only want to have enough thrust to push me along in the water faster than I or anyone else can normally paddle. The goal is to be able to catch waves easier and get out the back quicker. THAT’S it

I know these units aren’t meant for low speed applications but I want to use a water jet system due to the low drag profile they have (vs a prop) + the safety of them being internal.

Will the jet still be able to operate properly at high trust levels but at low water speeds ???? or will they stall due to the low speed / water intake ……. I’m not sure I haven’t designed these things.

I own 2 (real) jet skis so I’m failure somewhat with water jets but not rc ones.

I’m looking for a lot of thrust… NOT top speed so I assume I need to be looking for large jets with a big mass flow.

I can’t go much bigger than these 40mm systems as they won’t fit into the surf board properly.
http://www.cornwallmodelboats.co.uk/...pner_2340.html

http://www.jet-drive.de/cms/componen...chk,1/lang,en/

Do you guys think one system is better than the other? KMB vs Graupner

I am thinking about testing 2 of these to create a much static trust as I can. If that’s not enough I could try 4 of these systems.

It’s says the 40mm KMB systems can create10 kg of thrust. Do you guys have any idea how much HP / watts it would require to achieve this level of thrust?

I will install electric brushless motors that can run at about 1500 to 2000 watts each ( 2 hp ) ( 2.7 hp) if necessary for these 40mm systems. I was thinking about using these as a cheap motor to sort with http://www.hobbycity.com/hobbycity/s...idProduct=6679 they can handle about 1500 watts.


Or should I be using 6 smaller (28 to 29mm) systems to try and achieve higher water flow rate ( torque ).
http://www.jet-drive.de/cms/componen...art/Itemid,17/

http://www.cornwallmodelboats.co.uk/...pner_2345.html

These systems would be easier to install but I’m not sure if they’re going to suitable.

All the jet drives will be connected to a longer thrust tube because the drives will probably be mounted just after the half way point where the board is it thickets. I’m sure there will be losses associated with this.

OR I could mount them at the very rear of the board and have the jets almost fully exposed at the rear. I could run flexible drive shafts to the motors that can be mid mounted.
The rear of the board is always submerged with my weight.


Do you have any comments about what I am trying to do here ??

Do you have or know of a product more suited to my needs?

I know this sounds crazy but I’m going to do it. I just want give it a go because if I don’t its guarantied failure. So why not give it a try……I would love it if you would get involved.


Thanks for your help in advance.

785boats

Here's a couple of links that might give you some ideas. Click the links through the threads.
If Buddy the surfdog can build one Im sure you can.

[link]http://www.rcgroups.com/forums/showthread.php?t=921071&highlight=powered+surfboard[/link]
[link]http://www.rcgroups.com/forums/showthread.php?t=578001&highlight=powered+surfboard[/link]

I would go for the bigger diameter unit with a hi torque motor with a kv rating to give the revs nominated by the manufacturer.
I,m sure some of the guys from "The unofficial all things jet drive" thread on this site will offer better information than I can.

All the best.
Paul.

HSVXU6

That's one of the craziest things I have heard of for a while. I would look at the largest jets that you can fit in a board (why not buy a blank and form your own board and build to suit) You will need cooling for the motors which you should be able to get by inserting an aluminium plate/heat sink in the bottom of the board and have the motors come in contact with that for heat transfer by using heat transfer paste or similar. Keep the jet pumps as they are with no extra tunnel because of drag. Motors close to pumps and use batteries to balance board out. You will need a potentiometer or something to run brushless motors ( I am after something similar) Don't forget that water and electrics don't mix, no room for error so you will have to have everything well sealed. If you built your own board you could put aluminium stringers in and set everything out to suit the motors, batteries and jets. You might find that the easiest way to go and take less time and have a better end product you crazy bloke

HSVXU6

I have just noticed where you are from that explains it all. Only a Crow would come up with an idea like that and a Vic willing to help

Paul Turbine Jet Man

HEY HSVXU6

very funny had to be an Aussie didn't it LOL.


I know it sounds crazy and it is but you have to admit when i get this thing to work its going to be VERY cool

AIM : The aim is to get a power boost. My paddling power is good for 2-4 km/ph and if i can get with the assistance of the motors another 4 km/ph on top of that it would make a BIG difference !!!

W have purchased a 2nd hand 8 foot gun board that im going to do testing this idea with. When i get the bugs worked out and a good idea as to what works and what dosn't i will look at getting another really nice board or making one from a plug.

I am thinking of going with 2 x 40mm jets running on about 1000 watts each. Anything bigger and it would be hard to make it fit.

Do you think i would loose a lot lot of thrust if i ran them mid mounted and had a 4 foot long thrust pipe out the back ?



thanks for your input guys.


PS this was me a few years ago http://www.rcgroups.com/forums/showt...ered+surfboard
work got in the way and now im back to give it a go for sure.

pompebled

Hi Paul,

The motors Kehrer suggest are among the biggest (brushed) available, the Plettenberg 355/40/5 dwarfs the motors you mentioned, you'll need something more substantual like the hobbycity KB series, as the 36mm motors won't last long.

Watercooling these brushless motors is a must, using fullsized cancooling, as they'll be bogged down by the weight of the manned board.

I'm not sure it will work as you've planned, it may all go up in smoke...

Build it anyway and make a video.

Regards, Jan.

Umi_Ryuzuki

This dog could give you some tips...

http://www.youtube.com/watch?v=dNfwuM99mrk

[8D]

DIYeFoil

You can get the best of both worlds DIY Electric Surfboard, and my DIY Electric Hydrofoil if you make a quick connect on the power system and boards which is what I am doing. Check out my videos, posts, and photos at my site: ABOUT THIS SITE - DIY Electric Hydrofoil Video Series - E-Foil, & Electric Surfboard System

Got RPM

Eight-year-old dead thread dude! The OP hasn't even visited the site in years. Not sure if you are a commercial site or not, but it would be best for you to start your own thread, not jack someone else's - particularly such a dead one.


,

DIYeFoil

Yes I know, but the point of a forum is to help others, and with this web page popping up on 1st and second page of search engines for people looking for DIY
eFoil, electric hydrofoil and jet surfboards, why not share a post that is current and shows readers someone (myself) is starting to build one from scratch and will share the build videos... and keep posting on there if they have questions

DIYeFoil

There is new electric hydrofoil being developed on Kickstarter that will bolt onto almost any hydrofoil using different mount types and the project ends in 24 hours.