I have no expirience with my VESC 75/300.
I planed to mount my VESC on the bottom of my aluminiumplate and hope it will be enougt cooling.
When not, i user 4 from those cooling devices ( i bought theme aready) for cooling.
I may still do so, I want to see what it’s like without first. My thinking is the thing is rated for 300/350A continuous and I’m typically going to be pulling around 60A cruising maybe less as I weigh 70kg, I would be slightly peed off if it Couldn’t handle that and maintain a decent temperature.
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I’ll take a pic tonight mate and show you what I did with it. 
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I’m doing the same (Flipsky 200A in thermal epoxy to inside of aluminum box, no external cooling). I’ll report back how it goes on my build thread. Had to cut cooling due to time.
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I had the same thought: it’s built to handle so much more it must run cool by not pushing it hard. Let me know how it goes curious to find out.
Flipsky 200A can not handle 200A continuous. I has been discussed already in the “New Vesc 200A thread”.
I am running it without cooling, inside a waterproof aluminium enclosure, with thermal paste between the ESC and box.
I am pulling Max 34A battery current and it goes up to 53°C.
External temperature: 22 °C
I like your idea of mounting it on the top of the mast clamp, great for cooling.
I was toying with doing something similar to fliteboard, But that would of meant having someone to CNC a housing out of aluminium to bolt on top of the the clamp etc. Which lead to expense and more complex build.
Hi Thom! You have really helped me with this info. I had to cut out cooling and am doing exactly your setup now with aluminum box. Good to know heat is okay. Good to know current draw is low. It is still a mystery to me why motor current is higher than battery current though. Thanks again.
Best,
Peter
You need a really efficient foil and big wing to achieve such low consumption numbers. I didn’t have the choice since I have access to a waterproof battery with a BMS that only allow us to draw 35A max.
Regarding motor current, my undestanding is:
Brushless motors have a Kv that links voltage to RPM.
with 1V input, a 100Kv motor spins at 100RPM.
When you have an input in the ESC of 50V - 30A, this means 1500W, but your motors only spins at 2500 RPM, this means the output voltage of the ESC is in fact 25V.
But since the power input is 1500W, the amps in the motor is twice as much, thus 60A. 25V x 60A = 1500W.
Of course I neglated the internal ESC losses.
This is why motor amps is ALWAYS bigger than Battery Amps.
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Batt amp = motor amp x duty + a bit more , I guess from rotation … Benjamin explained this somewhere
The output is not 25v , it is « 50v or 0 » for not the same time so the average is like 25v
With the remote you adjust this time ( on/off) , the prop « takes » the amp needed from the battery through the motor
Thom-
Thank you again for the helpful comment. It really cleared it up for me. It’s a conservation of energy problem. We learned this in our physics series at Santa Clara University. I was not connecting it back to my education but it is very clear to me now. @Alexandre I understand what you are saying about each phase wire going high/low and you are correct. The ESC “turns on” each phase at the right moment to “kick” the motor some portion of 360 degrees. Get the timing right and you get a full rotation (Thanks Vedder). If you were to graph the high/low voltage it would resemble a square wave. A square wave is can be decomposed into it’s sine wave components. The term we learned is RMS (root mean square) voltage (you said average but meaning was not lost, I think of it this way too) to describe the DC component to a modulated signal. Anyways thank you both for reminding me of what I learned in school. I really appreciate it.
Best,
Peter
By the way- I have a Slingshot 84 foil and Rene’s optimized foil. One is very big and the other is very good at high speed. Of course, I am only reiterating the marketing as I’ve yet to complete my build and ride. May 18th is our scheduled maiden voyage. Slingshot wing first to learn to foil.
I also had this debate when I went with the VESC 300/75. From my research and the opinion of other users, it is very possible to run it without active watercooling. However, I’d look into adding a bigger heatsink or connecting it to an aluminum plate to help with some passive cooling. I have pretty much the same set up as yours and I decided to watercool the VESC. When I ride continuously for 1h+ at average speeds, it gets to 50-53C during winter Florida weather (75F outside, water a bit cool). So if yours is in a small compartment without any additional heatsink or alu or watercooling plate, it might get a bit hot after 30min of riding as the temperature inside the compartment increases and nothing helps to cool down the VESC. I suggest you keep an eye on the VESC temp during your first ride! If you have a maytech remote, you’ll be able to see it from the remote!
Well she flies!!.. few snags to sort though.
The main one is the remote, the signal strength is well dog shit!. When I’m up riding, no problem but if there’s any water of the back end which can’t be helped when you build up speed then it drops out straight away. Soooo annoying!. That’s with 2” of the antenna sticking out the electric box. Any suggestions?
Another was water getting into the hatch, which wasn’t a big deal as everything is waterproof but I still don’t want water in there.
Finally the metr app. I would click record put it in the hatch and then it would stop recording after 10seconds every time. Where I was had zero phone signal, does your phone have to have signal for it to work or is it clashing with the Bluetooth on the VESC? As I would really like to see some data.
Thanks
Which remote do you have ?
Regarding metr.at, where is your phone when you are riding ?
Regarding waterproofness, what seal do you use ?
I am using this one:
https://www.amazon.fr/gp/product/B07QRG79GP/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&psc=1
Works great, no leak.
Better turn off internal BT when using metr.at , at least at the time , didn’t check with update , but that was a problem for me
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Turn off “Automatic Record” and “Automatic Pause” in Metr Settings -> Record. Then it Will continue to Record until you stop it.
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I’ve got the Maytech V2 remote. Would a 2.4ghz antenna attached to the outside of the electric box boost signal?.
My Phones in the hatch right next to the electric box, couldn’t get any closer.
On my Eboard I’ve got a Unity esc and the metr.at works great. Do I have to allow any settings in the Vesc app for it?.
As for the seal I’ve used the Mold star 30 a saw someone use in another thread. I think it’s the latches, I’ve just ordered 2 of the Gemlux ones, hopefully they will do the trick. The ones I have are none compression.
Thanks, I’ll give it a try, hopefully it will do the trick. I noticed even on real-time it would just stop showing data after 10 or so seconds.