Why is it that car brushless esc's can run at

[DPeterson]

I run YGE's almost exclusively. I run 4S-2P full blown heavy boats. 9 -12 lbs. I run part throttle all day long. I use full throttle only to pass when the oppurtunity presents itself. Otherwise - full throttle causes me to blow off the water.

In my opinion. ESC's - get what you pay for.

Doug

[Gary]

My take on this subject is this. My boat comes in around 8 pounds. If you compare a car and a boat at the same wieght, same motor and same ESC they are going to have a drastic amp draws difference. Why? Lets look at a car . You can push one along with little drag as compared to a boat . A car just has aerodynamics to deal with. A boat on the other hand has Aero and Hydronamics....did i spell that right?....to deal with. Water drag is huge with boats and an esc gets loaded big time from this. Smack the throttle on a car and boom...its out of the gate. Do that with my boat and it loads itself big time from the prop and then finally gets on plane. This is what kills ESC's and also loads the batteries big time. Just my 2 cents

[RandyatBBY]

It is gears and wheels over props and hulls sliding over a surface. A lot more drag.

[EPower]

I just might have to put a max into a boat and see, of course Ill make a cooling plate for the heat sink first.

It might run for about 2 minutes

[ice_spy]

Ok this is great, so i agree that rolling resitance is very minimal in rc cars, ceramic bearings make the drive line very efficent. Gearing also contributes to a lot less load.
As opposed to a lot more drag on a boats hull in the water, also being direct drive. The 'loaded up' start is a very good point, and may have something to do with the soft start programming too. I was thinking more like a large blade say on a chopper that needs to be started softly not to load up the motor/batts too much. Same same.

But yes, all good answers and comments but still doesnt really anwser the Question.
If you get what you pay for.....show me a speed controller that has a good throttle curve. Even the most expensive ESC's in the world the SHULZE used by many FE boaters in Europe with NEU's, 10S etc. with a price tag second to none, they still have similar throttle curve. So i cant get what i 'would' pay for.

Vehicle resistance and load/s, Brands and Quality is one thing, amp ratings and true power delivery capability is another......but i all i want to know is why dont they have any boat brushless/lipo ESC's with small increament throttle curve? Would make driving a sport or scale boat a lot more realistic and fun. IMO.
Racing as many of you do, is yet to be tested for me, if it is really even an issue for FE boat RACING to have this feature as the car esc's do.

[AndyKunz]

Why don't we? Because we understand what is happening in the electronics. With a sensorless motor, we have to monitor the signal coming back on the un-powered leg of the motor (which is constantly changing), remember if we are currently energized or not on the other legs (and how), predict when we are going to need to commutate to both provide maximum power and prevent damage (did you know that missing the commutation point can blow your ESC in 1/6 rotation of the shaft?!?!).

Oh, and these all have to be done with microsecond precision in the correct sequence. It's not the trivial thing that a sensored motor needs to address (which can be done with a memory chip and NO micro).

Andy

PS: One-button setup is a pain compared to CastleLink or a card.

[paulwilliams]

Boat controllers have to cope with massive fluctuations in current, due to running across a surface that is constantly changing, with the load on the motor going from nothing to 2-3 times the controller's maximum continuous rating, possibly many times a second. Then you have the environment: hot, humid or outright wet, plus the constant shocks from the hull impacting waves - last time I looked, cars had suspension...

Some surface drive hulls, outrigger hydroplanes in particular, often don't work at all below a certain speed - throttle back too much and they drop off the plane completely, so fully proportional throttle control is arguably a waste of time. It's different with submerged drive ECO boats, throttle is used much more in this type of racing and these boats will plane at walking speed.

I suspect the majority of issues people have with speed controllers are more down to incorrect operation, not using a big enough controller and using power cables that are too long, rather than boat controllers in general being of a lower quality than car/flight controllers.

I would be interested to see data logger graphs from similar spec boats and cars.

Paul

[ice_spy]

Awesome replys, many thanks.
I also got this reply from my FE boat friend from PBS passau in europe.He racers the HPR 115 hulls with Shulze esc's and NEU motors.:-
please try to better understand his english, as this isnt his main language.

Hello Clint, no that is not a problem of boat ESC but mostly a problem of cheaper controllers.It is very difficult to write a good software with fine increments for bigger motors and its expensive too. Therefore many cheaper controllers are not really controllers, they work more like "multi-contact-switches" :D Most controllers here work very good, for Schulze or Modellbauregler you can't fell any increments, you can trim any RPM. Only initial starting sequence to a minimum RPM is the same for all the controllers. For car controllers: These controllers are all the same and use the same size of engines. Its also a mass procuct produced in very very high numbers, therefore even the producers of cheaper controllers can make a good software or what is very common too, they copy it from another producer. As the software has nearly to be the same for any controller who cares and controls this ? But as far as the controllers work very good it is no problem. I guess you ask because of your 30cm cat, concerning the video it looks a bit like you have a manual gearbox inside. Looks very funny when it suddenly makes a jump forward unless there would be the shore in front of it. Best regards from Austria,Manuel

[Flying Scotsman]

For boat ESCs there are only a few that come to mind that are tested and true. The Etti brand is making a name on the budget side. Boats and cars you can not compare as far as the demands on the controller. An FE boat is WOT and huge amperage draw..scale is another matter.

Douggie