Hi all, as far as fuses go I do not use them as I have small boats with about 15 - 20 Watts power and the esc can deal with a stall current. It has never been a problem with my models.
Roy

Hi StephenT, I answered your second question but I don't know if you read it or not, check your private messages if you want.

P.S. I still hear noise (maybe white noise) from people who don't understand that original photos and videos (of detailed construction phases, tests, etc.) cannot be the result of artificial intelligence. Its big bluff was called out long ago, but envy remains a nasty beast.
Out of politeness, I follow this rule: I provide my opinions, supporting them with facts, I answer questions on the public forum or privately (if asked), I describe my working methods and production phases, I ask questions, but I never criticize other people's comments and opinions. Nor do I allow myself to send insults privately.

Hi Roy,
Thanks for sharing your method for measuring the operating current of a brushed motor.
It's very informative, and I completely agree with it. We've already discussed this in connection with brushed motors with permanent magnets, if you remember.
One question: after finding the stalled current and operating current, what size would you choose for a fuse? Would a value between 20% and 25% of the stall current be appropriate, or would another value be appropriate?

Not everyone copies from the internet, especially lengthy posts filled with data nobody cares about. Just a few (maybe one?) that try to emulate AI. The vast majority on this site are wonderful, talented, and give great advice. They are the real "model boaters". Get a life!

Lew

Hi Black shoe. With unkown motors I use a rule of thumb approach. Assuming you have a volt meter capable of reading 20 amps I connect the meter in series with the drive battery and motor.

Using a pair of pliers I grip the drive shaft and measure the stall current. Do this for the shortest time as it can effect the permanent magnet.
The most efficient running of the motor will be with a load (prop) at 20% of the stalled current. You would be OK for running at 25% but this does work where performance data is not known.

If the numbers come out rather low then it is likely the motor was designed to run at a higher voltage than you are using.

Roy

Hi GregHiltz, thanks for sharing your method. I read your procedure with great interest.
At least you have a working method and you're not just talking nonsense, like someone who boasts of his experience but has little real substance and a knowledge base that's too limited to boast every chance he gets.
I understand you're in favor of using fuses and you've given excellent advice on choosing their size.
I also (after studying the factory data) perform tests directly on the model and take measurements in various conditions (both dry and wet) as I mentioned in the previous message (in fact, I wasn't just talking about theory, but always performing targeted tests).

Hi BlackShoe, I also really appreciate your approach and the measurements you take. Thank you for sharing it.
You're right, many engines don't have data for various reasons.
I have many whose specifications I don't know, but some of my technical knowledge and targeted testing help me conduct targeted checks.
I also made videos of the electrical measurement tests I've performed on ship models.

P.S. Anyone who thinks everyone just copies from the internet is doing it themselves and can't realize and accept that some people have real technical knowledge. Envy is a nasty beast.

Mr. Shoe, I agree with everything you said, right down to the paint. Advice from those who have real experience is valuable. Useless banter copied from the internet is just an annoying and has no real value.
Lew

Greg and Lew, I agree completely. The motors I use are mutts bought off the 'net with no pedigree, label, brand, or spec sheet, so manufacturer tech is non-existent. When I have a new build and after I've proven the watertightness, I put the boat in my small pond, put the bow against the edge and run the boat (single or twin screw) at full throttle with an ammeter hooked up in series with the motor(s) for an extended period of time. Monitoring the amp draw and feeling the motors for temperature occasionally I can garner enough information in real time without a lot of theory behind the build. (Theory is good, but someone telling you the stove is hot, is not the same as drawing close to it and discovering for yourself indeed, it's hot.)
Once I know the loaded amp value of the system, I simply install a breaker around double the running amp load and call it good. (I am an advocate of the "KISS" principle. I also don't use any artificially over priced marine bottom paint, but that's another subject.😊)

This is after all a hobby and as such should be enjoyed rather than getting bogged down with a myriad of principles and over-the-top confusing data unless of course that's the part of the hobby someone thrives on.

In my 50 years of gearing up and running R/C boats, I have always been cognitive of fusing my systems , as at sailings I have seen boats blow fuses out in the water, seen some burn up their motors, and others fry their ESCs.
If I am using a known motor with established Amperage draw , I won't test the motor operation for max draw, but will install a fuse slightly above the stall /max amperage. If it is a motor without specs , i will bench test with an Amperage Meter at free spin( no-load), then run the motor while pressing the shaft on the edge of my workbench (under working load), and I will then lock a Vise-Grip pliers onto the shaft and hold the motor against the workbench then hit the throttle/ connect the power briefly to get a maximum amperage draw for few seconds. With this info, I will size my fuse to be just under that max. Amp draw. This would represent the boat getting caught in the weeds or perhaps winding fishing twine around the Prop and causing a near-stall.
I would rather pop a fuse than ruin a good ESC or smoke my motor and possibly burn up my model.
Cheers

I don't worry about fuses. Only have one boat with fuses. Very frequently I have been running motorized RC boats for almost 20 years. (The last 10 includes RC tanks.) Only burnt out one ESC during that period. (BTW, one way to make smoke.) Also, I haven't seen fuses in RTR boats as well.

Lew

Hi Black Shoe

Correct fuse selection is a topic that's been discussed several times in this forum, and I wanted to hear others' opinions (because, in addition to the theory, which is mandatory to know well, I value my own and others' experiences).
I'll answer you right away, but keep in mind the opinions of other modelers.

I should point out that I only placed the fuse between the ESC and the brushed motor, although, in my opinion, it's also appropriate to place a fuse between the battery and the ESC.
So, I'll start with this first: the fuse between the ESC and the motor.
You need to consider the factory specifications of the electric motor (and if you do some current measurements yourself under different conditions, that's even better).
For the brushed electric motor, the manufacturer specifies three currents:
No-load output current;
Output current at maximum efficiency;
Output current at lock;
You know that if you brake the rotating pinion, the electric current increases to its maximum value until it completely stops.
I personally choose a fuse size between the "Output current at maximum efficiency" value and the "Output current at lock" value, but much closer to the former. I used to opt for one and a half times the "Output current at maximum efficiency" value, but now I've gone for double, but I'm not so sure (because I like to be conservative).
For example, for a motor with a 12-amp "Output current at maximum efficiency," I choose 25 amps, but some might prefer a lower value, while others might prefer a higher value, as long as it's much lower than the "Output current at lock."
I'm very curious to know the selection criteria and values ​​used by other modelers.
The fuse must not blow when the inrush current exceeds its rating, so instantaneous fuses should be avoided. Before taking it out on a lake, I always do extensive testing in the bathtub, which I recommend to everyone.
Regarding the fuse between the battery and the ESC, I base my calculations on this criterion (based on reasoning supplemented by the opinions of several experienced modelers).
The fuse size should be a few amps (some say at least 5 amps) below the maximum threshold.
By maximum threshold, I mean the maximum current that can flow continuously, not the maximum peak current.
I only consider forward gear, but if you want to be more conservative, consider the values ​​for reverse gear, which are typically lower.
Some modelers, adopting a less conservative approach, prefer to slightly exceed the maximum current that can flow permanently to avoid premature failure. In practice, slightly above rather than slightly below this threshold.
The important thing is not to consider the maximum peak current as a parameter.

There's also the issue of wiring.
The wiring should be suitable for the currents declared by the manufacturer. The fuse could also protect the wiring. Another weak point is the connections between connectors, but I don't want to delve too deeply into that for now.
Capacitors between the terminals of the electric motor are also useful for other reasons, but that's another discussion and for different reasons.

This article on permanent magnet brushed electric motors may also be useful to you.


https://model-boats.com/wiki/147457

no one has ever mentioned a fuse size before at my local club seems fuses are a black word I must admit only one of my boat has Any all this tech arguments cause great confusion we haven't got on the subject of two speed controllers rather than one that was my alternative the motors in my case are 550w brushed

Thank you.

Having revisited the thread I either missed it, or neither the proper gauge wire or the fuse value was mentioned for these potential amp loads.

Hi Black Shoe, I'm writing the reply, but it's taking time to translate.
In the meantime, I can tell you this: you don't need to apologize; I personally don't think you're being controversial at all.
Forum discussions are interesting and lively when there are differing ideas and opinions. The important thing is that it remains fair and courteous, without offense or unnecessary petulance.

Victor and Alessandro, sorry, I wasn't trying to be controversial, I was just sharing a couple of methods that work for me. I understand what the ramifications are of a stalled/disabled RC boat and what the potential results are.
My boats are slow, not very sophisticated, and pretty basic. SLA batteries, and brushed motors in every one with the exception of one that uses a LiFePO4 12.8V, but still brushed motors.
One point of confusion on my part.....with the high amp potential of the systems you advocate, what value fuse do you install?

So, in forward gear, the maximum continuous current you need to consider is 60 Amps.
360 Amps (not 180) is just the peak current.

Mine was the 860 dual brushed and I obtained very cheaply as it was the last one in the shop and I think that he wanted to be rid of it, it works fine.

Hi DenisA, if you used a Hobbywing Quicrun 1060 Brushed ESC

The maximum current values ​​are 60 A continuous and 360 A maximum in forward gear
The maximum current values ​​are 30 A continuous and 180 A maximum in reverse gear

If you used a Hobbywing Quicrun 860 Dual Brushed ESC
The maximum current values ​​are 60 A continuous and 360 A maximum in forward gear
The maximum current values ​​are 30 A continuous and 180 A maximum in reverse gear

If you used a Hobbywing Quicrun 1065 Brushed ESC
The maximum current values ​​are 25 A continuous and 100 A maximum in forward gear
The maximum current values ​​are 25 A continuous and 100 A maximum in reverse gear

These are the values ​​provided by the manufacturer, as per the attached manual.
In this same manual, you can see the various options adjustable using the jumpers.

I agree with you, VictorC.
Your argument is based on technical considerations.
In support of what you've stated in previous messages, I want to make an argument based on purely logical considerations.

There has been talk of a total loss of control of the RC model if a fuse blows.
Okay, but at this point I wonder: what's the worst thing that can happen to an RC model ship?

I believe there are three worst events: loss of control of the model, sinking, and fire.
In my opinion, loss of control of the RC model ship is the least serious of the three, while a fire is undoubtedly the most serious.

It's true that a blown fuse (for example, one located between the electric motor and the ESC) will cause loss of control of the model as it will be immobilized.
That's fine, but for now, it's safe.
A model stuck in the water can be recovered in various ways: if the water is shallow, some people use waders. If the lake is small and there's a bit of wind, the leeway will slowly bring it back to shore. Some say they moved it by rowing with the rudder.
It's still possible (and it's best to plan ahead) to recover the disabled model ship with another RC model ship, or with a small dinghy.
I don't think the problem really exists in small ponds.
I've sailed RC model ships in fairly large and deep lakes (the last one had a surface area of ​​5.58 square kilometers, was 8 km long, 3 km wide, and 68 meters deep), so I prepared a small dinghy for possible recovery. Without the dinghy, I would have had to swim to the rescue.
The possibility wasn't so remote because, in addition to having a fuse (which could have blown), I don't yet have an automatic or manual power reserve system, so I could have simply run out of battery power.

Let's consider sinking.
It's certainly worse than losing control. If the water is shallow, recovery is possible; if it's deep, recovery may be very difficult or impossible, and the RC model ship is lost.
In any case, even an RC model ship recovered after sinking will be severely damaged.

Let's take a fire as an example.
The same event that caused the fuse to blow could cause a fire.
In the event of a fire, it will be very difficult to intervene promptly to save the RC model ship before it sustains irreparable damage from the flames and sinks. If, hypothetically, you are able to intervene promptly to save an RC model ship that catches fire in the middle of a pond, then it will also be possible to recover a healthy RC model ship that is stuck due to a blown fuse.

About 3/4 of my ESCs are Quickrun 1060 brushed units. Even have some spares! Photo shows three in my 1/20 scale PT boat. Going to install one in my 1/16 scale semi truck.
Lew

Sorry folks the amperage I quoted should have read max amps 180 not 360 and I have run two brushed motors successfully with this quicrun unit from hobbywing.

StephenT, going back to your original question, "is it better to wire up two motors to each separate esc or can it be done with one 320 amp esc and to both motors they are brushed by the way"...

...it all depends on what you want to achieve and what RC system you are using. If you have a two channel RC system you will have to use one ESC. If you have multiple channels and a way to control two motors (like two joysticks) and want better maneuverability, especially when docking, I would go with two ESCs. They are not that expensive.

I pretty much have control over each motor independent of the others on all my boats.

(Never seen motors wired in series.)

Lew

I'm sure you're right in an industrial scenario. I was thinking more in the automotive realm and using a 12V 6A breaker between the motor and the ESC. The cost of the motors I've been using run far less than the cost of a good ESC and are more expendable to me than the ESC - although I have yet to burn a motor out. If something goes sideways between the wheel and motor I'd much rather protect whatever is upstream of the motor.
I have not considered how many times the auto breaker will trip before it "times out", but if it's three or four times would the motor develop a melt down at 6A that quickly?
Seems even if the breaker has a reset number limit (say 3) with a little finesse that's 3 chances to escape whereas a one time fuse is terminal.

The use of self reseting breakers has been suggested. In the electric utility industry these are called 'reclosers' and are set to lock out after a finite number (often 3) of closure attempts. This is fine for conditions like a squirrel across the lines (quite common), by the second or third closure the squirrel has been burnt to oblivion. Motor protection is quite different. Consider the case where the prop is caught in weeds or a fishing line has wrapped itself round the prop. With a fuse or a manual reset breaker that's it, the motor is safe. With a self reseting breaker the motor will see the stall current for a few seconds then off for a few seconds. The motor will not cool significantly in the off time, consequently it will heat up until failure of the winding insulation or depletion of the battery.

Hi Stephen, look in your private messages. I answered your questions in PM as you wanted.

A 320 amp ESC? Seems a lot of other stuff will "smoke" first.

I'm not sure why one would install two motors and not take advantage of what they're capable of....

On the subject of fuses: if your boat is across the pond and it ends up in the weeds causing your fuse to blow, you're dead in the water. If you have two motors, two ESC's, each one operating independently, you would have redundancy and a better chance of escaping. Another possibility is using self resetting breakers instead of fuses. If the breaker opens, one just has to wait a few moments for it to cool off and it'll be ready to go again. It may take a few cycles to get out of a bad situation, but they're not as final as a blown fuse.

Hi, John the brake you refer to on Chinese esc's usually has a tiny switch for turning it on or off. When on it provides regenerated braking used for model cars but when off it gives a straight reverse as in model boats.
Roy

Yes, two brushed motors are usually fine wired to one esc. Series or parallel wiring is good for this but I would think parallel is probably best. Just beware of brushed esc's that quote 320 amp max output, because few are actually capable of this.

Thanks for the excellent explanation, Victor.
I'm glad you're as supportive of using fuses as I am.
I'll add Victor and John to my previous post (#9).

Here are some design considerations.


1 Connecting both motors to a single ESC.

1.1 Ensure that the ESC can deliver the combined stall currents of both motors. The stall current will be considerably higher than the full load running current.
1.2 Install slow blow fuses in each motor feed between the ESC and the motor.
1.3 Install a slow blow fuse between the ESC and the battery, as close to the battery as possible.
It is unlikely that the motors will be matched, one will start before the other and likely run faster.

2 Separate ESCs
2.1 If they are fitted with BECs so that a separate radio receiver battery is not required then cut the red lead from one ESC to the receiver as the voltages will not be matched.
2.2 Install a slow blow fuse between the ESC and the battery, as close to the battery as possible. A fuse between the ESC and the motor is not required.
2.3 As it is unlikely that the motors will be matched, one will start before the other and likely run faster.
2.4 As it is unlikely that the ESCs will be matched, one motor will start before the other and likely run faster. Swapping the ESCs and motors may minimize this.

If your radio has more than 2 channels you could run a separate channel for each motor to give independent motor control.

In one of my two models with twin screws, I use two ESCs. I can use a further channel to select whether the vessel has independent control or combined control. (HMS Flirt 1898)

My other twin screw model has a home designed and built controller. Up and down on the left stick controls the power to both motors. Left and right on the left controls the balance of power between the motors. So that with the stick in the neutral position both motors are stopped. Moving the stick to the side will cause one motor to run ahead and the other astern. (USS Melvin) I built that in 1978-9, so far the only motor control fault has been a failed power transistor.

The other picture is one of my models with no propulsion motor at all.

Stephen, I would have simply said yes.
I would have based my answer on basic considerations, not least the fact that many ESCs are sold suitable for two brushed motors.
However, I'm pleased when I read comments from true experts like John and Victor who always tell you something extra and truly useful.
I'm asking, are you interested in controlling the motors separately, or is it not necessary?

I run one of these speed controllers in my Graupner Pegasus III it has pins to select forward and reverse, no wait for either direction.

How big are the batteries?

As you obviously already have the benefit of a twin installation, wire them separately (with 2 ESC)! This way you can spin on the spot (if desirable??) with one motor going ahead and the other one astern. I am very impressed with your 320 A ESC. Do you intend to sit in the boat and drive it Tesla-style?
Ian G

Hi there,

Take heed of all that has been said before - regarding 2 motors being driven from one ESC - as they do need to be fused - says a man who has experience of Fried Speed Controller syndrome 😋 .

The other thing to remember is that some speed controllers, especially from the oriental areas, have a built in brake in reverse and if you can't cancel this function; it can become quite embarrassing - especially when the model bounces off the side of the pond and you wonder why - even though your stick is in reverse - said the man with another medal to his chest 😆 . The model in question was Virgin Atlantic - the build which is in my harbour and also I have put a picture of the internals of it on here.

John stop before ya hit the side.

Are the motors brushless or brushed if brushed quicrundo a esc that is specific for two motors upto 300 amps hope this helps. i

If they are identical motors you should get a sufficient balanced drive. Just remember that the model motors we use are not precision units intended to be run in this way but a little trim on the rudder should overcome any difference in speed. However if one was to get fouled up then both would be out of action as you would burnout the fouled one if you continued to drive the boat on the other one. This could be overcome by having an overload cutout for each motor so a fouled propeller would cause the affected motor to become isolated. You could then limp to shore on a single motor.

I have never done it, but I don't see why you cannot wire both up to one ESC.
I have thougtht that it could be done myself.
I would think as long as you are using a powerful enough ESC as you are thinking then why not.
Also making sure tht the wiring would be sufficient also and fused.
I started to build a twin motored boat that used to be a cheapie NQD RC boat.
I took out the crap RC that was fitted and started to change to a decent RC set, but have never finished it.
I planed to do the same in that boat, the two motor's wired to one ESC, but up to now havenever finished building the boat.
I will one day, ONE ESC .