Electric Surf Board

Runtime 15 minutes devided into 3 sessions of 4-5 minutes. Capacity was 53Ah, after the three runs 30Ah left. So from 100% SOC down to 60-63%.
The only limiting factor is the MGM. It is getting too hot after the 4-5 minutes. Now I am thinking about an additional cooling system.
It is running really well. Top speed was 40km/h.
In this video 36km/h.
Actually I am thinking about going back to my 15S configuration....still waiting for an answer from MGM.
Have send them the data with all the parameters to check...
 
what part of your mgm was getting hot? the fets or the caps?

i was having problems with my caps, so i put a huge capacitor bank with watercooling on them and that seemed to solve it.

in the end i was having problems with my batteries getting hot, especially if i full throttle to 54 kmph, and some of my cells started to fail/internally short. i had 2 watercooling plates on my batteries, but i think i needed a bigger pack, was running 14s 12p, but having seen the lampuga taken apart here, seems i needed a 14s 20p
 
Hi Chris,
No it is a 14S1P configuration.
The cells are KOKAM cells, each cell 53Ah.
The caps are okay, the internal temperature of the MGM says to hot...and then the power is automatically reduced.
How did you solve the cooling of the capacitors, sounds really interesting to me.
 
fabianpusch said:
Hi Chris,
No it is a 14S1P configuration.
The cells are KOKAM cells, each cell 53Ah.
The caps are okay, the internal temperature of the MGM says to hot...and then the power is automatically reduced.
How did you solve the cooling of the capacitors, sounds really interesting to me.
Click to expand...

i have watercooling plates on the batteries, ill take a photo tomorrow. and the external caps bank just lays between the cooling plates.

thats strange that the fets are overheating, how much water are pumping through the mgm cooling plate? i never had a problem with the fets getting hot
 
Okay, thats interesting.
I have never measured the waterflow. On the next Saturday I have planed to do some tests.
Water bypass from the jetdrive vs. 12v waterpump.
I think it should be possible to make that test stationary.
Watercooling is really difficult to handle because of the height..only 10mm left.
 
yeah, check the waterflow, the fets on mine never get hot, also what motor timing are you using? more degrees timing keeps the fets cooler, but gets the battery and motor a little hotter.
how much did that battery cost, looks like the proper shiz
 
At the moment I am using 15 degrees.
What timing have you set up?
The battery was with a special prize 2000 Euros for 17 cells. But add on there is the BMS, which is nearly 600 Euros.
So not a cheap solution.
Have you installed an additional waterpump?
 
i was running 20 degrees, and the fets were getting close to max temp, then i increased to 25 degrees, and the fets were cooler by about 8 degrees.
im running cooling from the jet drive, but it pumps a lot of water through the system through 10 mm diameter hose
fets are stable around 60 degress c
 
Chris which kind of motor is your actual model?
I will try that timing setting the next weekend.
I am really looking forward to see an influence.

If you are interested in such a battery, let mw know.
I am thinking about to buy a 30Ah version. So as a light back up. The 53 for the holidays and the ligther version for easy handling.
 
fabianpusch said:
https://youtu.be/hzqdDyQC6nw

Greetings from Corsica.

Your petrol powered board is amazing....really fast. Great job...and a perfect lake with best conditions. Where is it?
Click to expand...

Very beautiful. :bigthumb:
Which MGM controller and jet drive are you using?
 
Hi
It is the MGM 250-63 HBC - industrial version. It is more or less the same like the 400-63 RC version.
The jetpump is a modified 64 MHZ version.
By Fabian
 
fabianpusch said:
Hi
It is the MGM 250-63 HBC - industrial version. It is more or less the same like the 400-63 RC version.
The jetpump is a modified 64 MHZ version.
By Fabian
Click to expand...
Great job on your board, you have been working on it for long time. I have the jet 64 setup on my jetboard too but the battery pack cannot handle the load so I must go for a powerful battery setup.
 
Yes, you are right. The battery is the bottleneck.
It is not so easy to find a lightweight solution with a high output.
But at the meantime I am really thinking about to sell all the stuff...my partner is going mad with the first 2 boards hanging around and the actual one which is in our guest room 🤪
 
I also think, that the jetpump could be optimized e.g. more pitch.
Has anyone optimized the MHZ Jet?
I am also trying to build up a pump for 80mm, a target rpm 8000-9000....anyone interested
 
fabianpusch said:
I also think, that the jetpump could be optimized e.g. more pitch.
Has anyone optimized the MHZ Jet?
I am also trying to build up a pump for 80mm, a target rpm 8000-9000....anyone interested
Click to expand...

You know, mhz is not efficient at all because it needs to run high rpm which causes to many problem and losses. That is why Lampuga went under before it was bought also, those who had jet64 gave up because of the same cause. MGM ESC has a 32 bit system and Flier ESC has a 16Bit system there's a difference. They can work properly when the timing and PWM is tuned correctly. Too many variables to consider however, I came down to conclusion if you buy a mhz jet system you need to spend over $3k/€2.5k then you will see somewhat of a great success if you build the system right. The main issue is heat.. heat.. Heat. Motor gets hot to a certain Celius there is magnetic loss means pulling more current then controller gets hot and if the battery cannot handle the load well you know what is next. The 80mm pump is a great idea at 8000-9000 it will be manageable.
 
I forgot to mention, I now have access to the best 3d printers in the world. Did a tour onsite and learned the machine operations to much to digest in learning. They can 3d print in metal too, which the service more expensive. Overall I see a future in production run for jet pump system using this company. May take a visit today.
 
That sounds cool, I am trying to animate a PhD in fluid technical systems and my old connections to Formula1. I think building up a jet is not impossible. The hardest thing is spending money for the itereations and the prototypes.
By the way, we have multi jet HP printer and also some DMLS metal printer in our company.
I have printed the frames for the opening and some other parts, really good and durable stuff...
 
Hello,

I will sell my lampuga Air 2016 because i switch to a Jetsurf....

Best Regards:)
https://www.ebay-kleinanzeigen.de/s-anzeige/lampuga-air-2016-jetboard-jetsurf-/1224885023-241-2930
 
FYI anyone have any thoughts on the pumps from the following supplier, they also have a 55mm and 80mm setup. Not so sure about the impellers. I am just hoping there are options to get metal impellers.
https://www.aliexpress.com/item/4000147399664.html?spm=2114.12010615.8148356.11.3c0572a8NA0K0b

This guys youtube is a riot too, with great info.
https://www.youtube.com/watch?v=6GRExuEdd5A&t=255s
 
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