Search found 82 matches

by chris_kline
Aug 11 2019 10:10am
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 672
Views: 163137

Re: Electric Surf Board

heres a photo of my hatch, aluminium flange, with a rubber gasket, and thumb nuts for fastening it down
by chris_kline
Aug 09 2019 10:51am
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 672
Views: 163137

Re: Electric Surf Board

ill post a photo tomorrow of what i did with my hatches. basically i just had a rubber gasket cut for me by a company who cnc cuts gaskets for plumbing and oil industry etc 60mm pitch is a little low, especially for a 60mm diameter prop, you would need to get that nozzle pretty small to create enoug...
by chris_kline
Aug 09 2019 4:39am
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 672
Views: 163137

Re: Electric Surf Board

inlet is equivalent to about 80mm diameter. i think the 60mm prop should be fine, whats the pitch of it? just reduce the nozzle size to get more thrust, it will make a huge diference. 4kw @ 10000 rpm is very low power for that rpm. mine consumes about 10kw at 10'000rpm ive found, going over 14000 rp...
by chris_kline
Aug 09 2019 2:59am
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 672
Views: 163137

Re: Electric Surf Board

45mm nozzle, 76 diameter prop, with 70mm pitch
by chris_kline
Aug 08 2019 12:32pm
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 672
Views: 163137

Re: Electric Surf Board

my electric jetsurfer has about 150l of volume my gas jetsurfer has about 90l of volume. my gas jetsurfer sinks if im not moving, but i wanted it smaller to be more maneuverable. if you decrease your nozzle diameter at the small end, you will get a lot more thrust, and will get on the plane almost i...
by chris_kline
Aug 05 2019 7:26am
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 672
Views: 163137

Re: Electric Surf Board

yeah, those Esurf boards look very well made, next gen stuff.
but they cost like 20'000 so for that money, you would expect the best!
by chris_kline
Aug 03 2019 9:01am
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 672
Views: 163137

Re: Electric Surf Board

yeah i contacted them when i was in the middle of my troubles with mgm.
they said they werent really able to get the erpm needed
by chris_kline
Aug 02 2019 3:00pm
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 672
Views: 163137

Re: Electric Surf Board

mould for the board? no this one was hand made, from expanded polystyrene foam and wet lay carbon like the last one, i just got a bit better at doing it this time :D the motor compartment was made with a mould though, and prepreg carbon, but i dont have a big enough autoclave for the main board to fit
by chris_kline
Aug 02 2019 2:00pm
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 672
Views: 163137

Re: Electric Surf Board

looks well made, would be interesting to know what the max erpm is on that. im thinking it would need a watercooling heat exchanger on those fets for a surfboard application though. thing is on watercraft you are operating at a high load constantly, its like gong uphill all the time. about mgm, mayb...
by chris_kline
Aug 02 2019 4:59am
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 672
Views: 163137

Re: Electric Surf Board

yeah, well they must have figured out a way to stop them exploding. maybe they went with external watercooled caps banks also, or maybe they just tuned the resonance out of the caps with specific wire lengths and battery configs, and esc settings. through a combination of increased motor timing to m...
by chris_kline
Aug 01 2019 4:06am
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 672
Views: 163137

Re: Electric Surf Board

eventually i got so sick of the problems with the esc, mgm, and the cells, that i built a gas jetboard from a 2 stroke racing kart engine. i know this is an electric power forum, but i hope you dont mind me posting a couple photos and video of the second jetboard i made. here it is part way through ...
by chris_kline
Aug 01 2019 3:57am
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 672
Views: 163137

Re: Electric Surf Board

I spent a year messing around with my jetboard, but every time i took it out, there would be some electrical problem. the esc kept blowing the caps, mgm are literally the wors company to deal with from a customer care perspective. i made external caps banks, which helped, and made an additional wate...
by chris_kline
May 05 2018 2:25pm
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 672
Views: 163137

Re: Electric Surf Board

Hey Chris Can you give me some details of your installation. Especially the lenghts of cables, cross sections, connections, placement of the additional cappacitors. I had the same failure twice. My first thoughts had been also the same: Should shut down automatically internal safety algorithms Coul...
by chris_kline
May 03 2018 5:26am
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 672
Views: 163137

Re: Electric Surf Board

that was my thoughts when i sent the esc back for diagnosis.

nevertheless they will not honour their warranty in this case.
by chris_kline
May 03 2018 5:05am
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 672
Views: 163137

Re: Electric Surf Board

quick update

my mgm controller failed. they will not repair or replace it, and suggested i buy a new one.

thats pretty bad customer service in my opinion.

looking at alternatives, incl self developing a controller.
by chris_kline
Apr 04 2018 3:09pm
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 672
Views: 163137

Re: Electric Surf Board

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!!
by chris_kline
Apr 04 2018 3:09pm
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 672
Views: 163137

Re: Electric Surf Board

toto44 wrote:
Apr 04 2018 10:00am
Printed everything, nearly ready for first testrun.
IMG_1169.JPGIMG_1168.JPG
looking very slick!
by chris_kline
Apr 04 2018 8:55am
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 672
Views: 163137

Re: Electric Surf Board

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 manu...
by chris_kline
Apr 02 2018 4:00pm
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 672
Views: 163137

Re: Electric Surf Board

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 lik...
by chris_kline
Apr 02 2018 3:54pm
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 672
Views: 163137

Re: Electric Surf Board

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
by chris_kline
Apr 02 2018 1:13pm
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 672
Views: 163137

Re: Electric Surf Board

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
by chris_kline
Apr 02 2018 1:11pm
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 672
Views: 163137

Re: Electric Surf Board

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 a...
by chris_kline
Apr 01 2018 3:01pm
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 672
Views: 163137

Re: Electric Surf Board

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 som...
by chris_kline
Apr 01 2018 2:23pm
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 672
Views: 163137

Re: Electric Surf Board

toto44 wrote:
Mar 19 2018 9:12am
Hello,

I created completely new jet. It will be availible soon for download, after I printed and testrun it. Here are some pictures. I improved bearings, added grease nipples, better waterflow..........
i have to say thats a nice piece of design work. is it going on a jetsurf?