Brushless Motors

[Tim CooperParticipant @timcooper90034]

Just a query about Brushless motors.

Looking at the Leopard motors on the Component Shop site I see that they have 2 versions of the LC 2826 motor, a 15T and a 17T . The 17T has a kv of 1050, max power 155W, 13 amp max and max pull of 0.92: the 15T has a kv of 1150, max power of 171W, 15 amp, max pull 0.88.

Would there be a lot of difference between the two in a Model boat? I was originally thinking of using the 17T but have now,noticed the 15 T.

Thanks

Tim

[Tim CooperParticipant @timcooper90034]

[Dave MilbournParticipant @davemilbourn48782]

Would there be a lot of difference between the two in a Model boat?

If you were to use identical props, battery packs and speed controllers in identical boats then I doubt you'd notice any significant difference between the two motors. The 15T might be marginally quicker on acceleration and you might get marginally better low-speed control with the 17T, but that's about it.

Dave M

[Dodgy Geezer 1Participant @dodgygeezer1]

Brushless motors are made primarily for the aircraft boys – frequently the droners.

For aircraft use these motors are often operated at the peak of their performance envelope, and require lashings of air to be blown over them to keep their temperatures within limits. I suspect that operating at this level, you would see a difference between the motors, though, as DM says, it would not be huge. However, it would be important in a race….

Boaters rarely seem to operate brushless motors at their limits. It's much easier for us to operate at 50% or less power and not worry about cooling at all. If operating in this regime, as DM says, you probably won't notice any difference…

[Tim CooperParticipant @timcooper90034]

Thanks for the answers.

Tim

[Malcolm FraryParticipant @malcolmfrary95515]

If the intended controller (being the "other half" of the motor) has a quoted turn rating, going below would not be a good idea. With small numbers, even a single turn is a sizable percentage.

If both are OK with the intended controller, it comes down to finding the best prop to go with it to get the boat to do what you want (speed, acceleration, controlability, run time) if you are actually using the motors to their max. If running in the middle of the performance curve, it becomes more a matter of tossing a coin and belief, but I would incline to the higher turn figure.

[Tim CooperParticipant @timcooper90034]

Thanks Malcolm

I will go with the 17T motor.

Tim

[BRYAN ASTONParticipant @bryanaston57723]

Greetings all

If you have a matching brushless motor and esc which come in a kit ,surely they should work out of the box in default mode and not need programming?

I have a number of brushless motors and brushless esc that have never run,I also have a brushless system that has run perfectly straight out of the box, what an I missing?.

Regards

Puzzled Bryan

[ashley needhamParticipant @ashleyneedham69188]

Bryan. Yes, they will work straight out the box but there are a lot of settings (usually) you can twiddle with and the important ones concern what type of battery you are using, cutoff voltage and possibly the failsafe setting…ie….half power or cutoff (to motor) on low voltage.

​Its not always possible to use the same gear …..but I am trying to only use JP EnErG pro aircraft type ESC`s for which I have a program card for;

​It is advisable to get a program card…they are cheap and the default aircraft setting may not suit boat usage always.

Ashley

[BRYAN ASTONParticipant @bryanaston57723]

Ashley

I have the programme card for them and they still don't work.

Bryan

[ashley needhamParticipant @ashleyneedham69188]

Bryan. Assuming you have tried different batteries and if its an aircraft esc the stick is set all down, and poss you have tried a different motor…then I suggest a phone call to the supplier??

Ashley

[BRYAN ASTONParticipant @bryanaston57723]

Ashley

I bought a Mtroniks Hydra 15amp combo set recently for my Diva and it worked perfectly straight out of the box, why can't other combo sets do the same. The only downside is they are not cheap, but they save a lot of trouble.

Regards

Bryan

[BRYAN ASTONParticipant @bryanaston57723]

Ashley

Just a thought ,I normally use a Flysky pistol grip trans. Would that make any difference to the set up?

Bryan

[Dave MilbournParticipant @davemilbourn48782]

Bryan
I'm curious to know which motors and ESCs come "as a combo" or "in a kit". I was only aware of the MTroniks ones. As Ashley says, if they do come actually held out for sale, matched and packed as a combo then they should work together either straight out of the box or once set up according to the instructions and without recourse to an additional purchase e.g. a programming card.
As far as your transmitter is concerned it's possible that the neutral signal is not the industry standard 1.5mS and/or that there is more 'movement' ahead than there is astern. In that case either test the motor/ESC out with a different radio [one with a spring-centred stick on the throttle] or use the steering channel on the wheel transmitter to test it. At the end of the day if you've done everything according to the instructions and you still can't get the thing to work then a replacement or refund would seem to be in order. If you bought them direct from an overseas supplier then that might be the most insurmountable problem you have.
Good luck.

Dave M

[ashley needhamParticipant @ashleyneedham69188]

Do you have another transmitter to use? borrow or wotevea?? Ashley

[BRYAN ASTONParticipant @bryanaston57723]

Dave

The other kit I have besides the Mtroniks is an Etronix Photon 2.1w Sensored/Sensorless esc with brushless motor, all comes in a kit, I bought it around 18 months ago and I recall now it worked once straight out of the box and next time I used the boat , which was months later it was no go and I have played around with it from time to time,I now have the whole system mounted on a board .

Ashley

I have another brushless motor and I will swap the motors over and I have an Etronix trans. and receiver and we will see what happens.

Does anyone know if the Mtronix esc would operate any brushless motor ?

Thank you both for your suggestions

Bryan

[Dave MilbournParticipant @davemilbourn48782]

Bryan

All I can suggest is that you go over it carefully and check for broken or badly-soldered joints to motor, battery pack and connectors. Then it's CSI time…. trying each component in the system with alternatives e.g. try the ESC with a different radio, then with a different motor, then with a different battery pack. When the problem follows the component you'll know which one is duff.
In theory the MTroniks ESC should operate another sensorless brushless motor as long as you keep it within the recommended limits i.e. current drain, battery voltage. If in doubt give them a ring – they are very helpful folk.

Dave M

[Malcolm FraryParticipant @malcolmfrary95515]

When trying to sort problems involving ESCs, one of the first things to try is a servo tester. You get a standard signal and no questions about the radio, because it isn't in the system at the time of testing. Also saves the hassle of forgetting to turn the transmitter off. They are so cheap nowadays, every home should have one.

[Dave MilbournParticipant @davemilbourn48782]

Malcolm is dead right – here's the one I have, but there are others **LINK**

I like this one because it will send a standard neutral signal to centre a servo or put an ESC at dead stop, and it also has a very useful cycling function which runs a servo/ESC continuously from one end to the other without the need for turning the knob.

DM

[BRYAN ASTONParticipant @bryanaston57723]

Greetings all

Have tried different motors ,different batteries ,different brushless esc, different trans. And receivers ,result zilch,not even a murmur or twitch,I give upI will contact Mtroniks during the week, thank you for all your suggestions

Regards

Bryan

[BRYAN ASTONParticipant @bryanaston57723]

Greetings all

I have been in touch with Mtroniks and they tell me that a Hydra brushless esc will operate any sensorless brushless motor provided that the max current of the motor does not exceed that of the esc.

I thought that this may be of interest to somebody.

Regards

Bryan

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