Search found 60 matches

by srn
Sep 05 2018 12:06pm
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 635
Views: 141951

Re: Electric Surf Board

hello guys, i am still testing in my small pool. now my remote control is working fine. Also the new propeller is doing a very good job. here my current MGM log. I wonder that I have really small power consumption at 10.000 rpm. At the moment I limited the MGM to 10k rpm for testing. Will try 12k rp...
by srn
Sep 03 2018 12:36am
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 635
Views: 141951

Re: Electric Surf Board

ropower86 wrote:
Sep 02 2018 2:24pm
How much did it cost you to 3d print in metal?
I ordered a 62x62mm. They said that it will shrink 2-3% after thermal treatment and finally I got a 60.5 x 60.5 impeller.
It is ~95€.
by srn
Aug 31 2018 9:36am
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 635
Views: 141951

Re: Electric Surf Board

toto44 wrote:
Aug 30 2018 10:04am
Hello SRN

what pitch does your impeller have? Did you balance it?
Hello toto,

the pitch is 60mm or equal to D if you scale it.

I have not balanced it yet.
by srn
Aug 30 2018 6:44am
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 635
Views: 141951

Re: Electric Surf Board

madin88 wrote:
Aug 30 2018 4:37am
how much did it cost?
I ordered a 62x62mm. They said that it will shrink 2-3% after thermal treatment and finally I got a 60.5 x 60.5 impeller.
It is ~95€.
by srn
Aug 30 2018 3:37am
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 635
Views: 141951

Re: Electric Surf Board

Hello,

i changed my carbon impeller to a 3D-printed steel impeller. It is really impressive quality and less vibration.
IMG_3664.jpg
today I will make first measurements of power consumption. Will provide results later.
by srn
Aug 20 2018 1:56am
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 635
Views: 141951

Re: Electric Surf Board

Hello toto44,

good video, looks like a lot of thrust for this small motor. Do you have a log of motor/esc power during this run ?
by srn
Aug 16 2018 4:14am
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 635
Views: 141951

Re: Electric Surf Board

I already reduced voltage to 8S which did not make any difference. The MGM controller is tracking the "input current" and the "peak current". I thought that the Battery to ESC current is the "input current" ?? This one is very stable so if I am right, there is currently no need of capacitors or shor...
by srn
Aug 13 2018 1:52am
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 635
Views: 141951

Re: Electric Surf Board

Really strange picture. I think you are right with the remote input, seems to be 0 or 100%. What about your cable lengths? Do you use additional caps. About settings, try to increase the acceleration time...to 3 or more seconds. Next use a servo tester as input and check everything again. Hello Fab...
by srn
Aug 12 2018 6:39am
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 635
Views: 141951

Re: Electric Surf Board

Here my graph after adjusting shaft and reducing system voltage from 60V to 30V.
Controller 2 history 2018-08-12 13-34-59.jpg
The peaks are still very high. I am also wondering about the input request. Seems that my remote control is only sending 0 or 100%.
Will check this before next try.
by srn
Aug 12 2018 5:39am
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 635
Views: 141951

Re: Electric Surf Board

Frizzo wrote:
Aug 12 2018 5:10am
Hi Srn,
With what battery configuration did you go btw?
Hello Frizzo,

I am currently using the Turnigy Heavy Duty 4S 5Ah Lipos. They are rated with 60C (120C burst).
At least for testing they do a good job. Have them in 2S2P now.
by srn
Aug 12 2018 1:06am
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 635
Views: 141951

Re: Electric Surf Board

Yes I ordered directly from Lehner, in april this year.
by srn
Aug 11 2018 4:56pm
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 635
Views: 141951

Re: Electric Surf Board

Hello Mgivens,
my motor looked already like this when i got it. I also wondered, because i expected black-purple. Dont know but i dont need color on it.
B11178D6-338A-43FA-9A85-EC61EC0FD1F7.jpeg
by srn
Aug 10 2018 3:36pm
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 635
Views: 141951

Re: Electric Surf Board

The Impeller should be too small (60mm) for the Lehner Torqstar 7050 275kV.

I found that there was high tension on the shaft. Will adjust it again and do another try.
by srn
Aug 09 2018 3:40pm
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 635
Views: 141951

Re: Electric Surf Board

Hello Fabian,

do you know why this peaks can occur ? You see on following graph, that the average input current is 10 - 20 A.
Peak current is at motor side, maybe I have too fast acceleration ? I will reduce it and try again.
Controller 2 history 2018-08-09 22-32-24.jpg
by srn
Aug 07 2018 3:32pm
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 635
Views: 141951

Re: Electric Surf Board

Hello guys, here some updates of my project: Today I made first water tests in a small pool (after fixing all sealing issues last days). It worked very well, also the water cooling, which I made according to Frizzo's suggestion. IMG_3577.JPG Here two log files of my controller. The peak current look...
by srn
Jul 23 2018 12:09pm
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 635
Views: 141951

Re: Electric Surf Board

bigbore wrote:
Jul 23 2018 10:03am
The water is generally drawn through the outlet nozzle with a radial outlet
How about salt water, sand and dirt ? Anyone who had problems with direct cooling from nozzle water ?
by srn
Jul 23 2018 6:45am
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 635
Views: 141951

Re: Electric Surf Board

Hello,

my board is finally running (atm only dry for testing).
Now I am thinking about cooling. I have the watercooled Torqstar 3 and the watercooled MGM 40063.

How do you get cool water into your Motor and ESC ? Do you use external water or maybe a closed internal water circle with pump ?
by srn
Jun 05 2018 4:35pm
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 635
Views: 141951

Re: Electric Surf Board

Hi & good morning Longtime full load is about 240 Amps for 5 seconds. Not too much - I think the problem will be the cable lengths from the battery to the controller. There are indication high internal peak currents (about 600Amps) and this is too much for the caps. Install the controller as close ...
by srn
Jun 04 2018 1:13am
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 635
Views: 141951

Re: Electric Surf Board

Hello Fabian,
did you read the log of the ESC ? Was ist long time full load? Too hot? High peak load ?
by srn
Jun 03 2018 3:59am
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 635
Views: 141951

Re: Electric Surf Board

Is it the MGM ESC ?
I would contact the supplier directly. Maybe now they would just change the capacitors while when you go on, you destroy more..
by srn
May 05 2018 3:00pm
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 635
Views: 141951

Re: Electric Surf Board

Chris, do you know what went wrong?
by srn
May 03 2018 8:03am
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 635
Views: 141951

Re: Electric Surf Board

what did you do ?

the controller should also shutdown in case of too high temp ?
My MGM controller will arrive end of next week.
by srn
Apr 17 2018 9:22am
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 635
Views: 141951

Re: Electric Surf Board

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...
by srn
Apr 17 2018 4:51am
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 635
Views: 141951

Re: Electric Surf Board

Hello ZR38,
Good question, at the moment I think to measure the thrust a kind of spring-scale should be the best.
by srn
Apr 16 2018 9:48am
Forum: Electric Watercraft
Topic: Electric Surf Board
Replies: 635
Views: 141951

Re: Electric Surf Board

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/powe...