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[bosun]

HY GUYS
I recently bought a Mtronics 25 amp ESC, I have connected as per insturctions, but I find that the battery and ESC are getting really hot, the intended battery is 12 volt , but this is happening on a 7.2 volt as well. The rudder servo is working but the 12 volt motor does nothing, I changed the motor but it is exactly the same (dead). The instuction sheet says,,,If you are using an external reciever battery, you must remove the red wire from the reciever lead, is this the little power pack that has 4 seperate batteries ?, and could this be the problem.
I have also tried removing the reciever on/off switch and the rudder servo, thinking it would lessen the load, but it is still the same. I have blown two in line fuses 7.5 and 10 amp .Any help would be really apreciated. ???
Thanks in advance
Bosun

[Faraday's Cage]

Bosun,

What type / size of motor are you running ? Not brushless I hope !

Have you tested the motor across a battery to check that its ok ?  In situ would be best option ?

Have you any suppression capacitors fitted ? Could these be shorting out ?

Are the fuses blowing instantaneously or after a period of time ? If instant then you probably have a dead short in the wiring / motor. If after some time then seems to be that the current draw is too high.

If you are using a separate receiver battery pack (4 x battery pack) then the red wire from the 3 core cable coming from the esc to your receiver needs to be disconnected. It is possible to remove the cable and pin from the plug, with a little care, so if you need this facility at a later date you can reconnect the wire and plug.  Having said that I would be  surprised that this was the cause of your problems from the symptoms you describe.

We may be able to help you further if you could  give a little more info.

Terry.

[bosun]

Hy Terry
Thanks for getting back to me so quickly, The motor is a 12 volt  I believe 12 pole taken from a bath lift used for disabled people, in looks it is very similiar to the new ones at  MMM, I am sorry i have no idea if it is brushless ,how do I tell ?
There are no suppresion capacitors fitted as yet, I was waiting to see how it would all work out, what ones would I need.  I have  bench tested the motor with a battery and it runs excellent forward and reverse, in situ there is no load on it, but it does,nt run. The fuse is,nt blowing straight away but it does,nt take to long under 20 seconds I would say. I have been given 8 of these motors, but I know little about them except for their former use .Hope this info is of help
Bosun (also Terry )

[Faraday's Cage]

Hi Terry (good name that),

No, they are not brushless type motors or else they wouldn't run on the bench.  I suspect they are drawing quite a bit of current hence the fuse blowing after a short period of time. Ideally you could do with finding out what the current taken actually is using an ammeter in series with the motor and battery and setting to the 10amp setting on the ammeter.

Have you got a different type of 12 volt motor you could try with the esc. This will prove that the esc connections are ok and esc as at least working.  Its going to be a matter of trial and error on this one but don't give up. Change 1 thing at a time and eventually you'll crack the problem.

Terry.

[bosun]

Hy Terry (excellent name)
I have recharged the 7.2 battery and had another go at the problem, as soon as I switched on the esc there was smoke coming from it and the fuse itself basically melted, I pulled the wires apart and waited for the esc to cool down, it all seems to be working ok,(at least it is lighting up) I have since tried another 12 volt  but different motor and have the same result ...the rudder servo is working fine but nothing on the throttle, the one thing different seems to be  no heat this time, but I have,nt left it for any length of time for any thing to materialise.
Bit wary now
Many Thanks anyway Terry, apreciate your help
Bosun (Terry )

[FullLeatherJacket]

Most of these multi-pole motors are not suitable for model boats. There - I've said it, and someone had to. Sorry - but that's not just my opinion. They generate a fearsome back-EMF and enough generator current to power a small city. They will eat most speed controllers for breakfast unless they are equipped with Smart FETs. These are EXPENSIVE.

Don't buy these motors. Don't fall for their Mabuchi-sounding numbers. They belong in industrial robots or military equipment (or bath-lifts, God help us), not in model boats.

My advice to you would be to junk the thing and invest in a cheapo 3 or 5 pole Mabuchi or Mabuchi clone. It'll work out to be far less trouble in the long run.

Works for me - and most other people too. Suit yourself.

FLJ

[bosun]

Hy FLJ
Thanks for your response, I think I have to agree with you, I am not very good with electrics, I get by and with only you guys to ask it is sometimes a struggle, I have 3 tugs and a fishing boat and have had no problems with other motors, trying this new motor out seems to have taken its toll on the esc, it is showing all the signs of working ok but it is not operating at all, there you go I suppose we all live and learn (bl**dy expensive lesson though) so now its a new esc and a different motor, what do you suggest for the Nangee.
Many Thanks
Bosun

[Ghost in the shell]

well probably a graupner or mfa 5-pole motor :)

[justboatonic]

Well I think you've fried the ESC by now if smoke was coming from it. If you are using a 12v sealed lead acid battery they actually have a voltage of around 13.5 - 14v or more when fully charged. The MTroniks ESC while is rated for 12v and the extra volts plus the motor could have done damage by now.

I'd recommend only using RC designated motors since they are specifically designed for cars, boats or planes.

[Ghost in the shell]

also for an esc, if you want to run 12v, try electronize, (you may need a seperate supply for reciever though) or a Proboat tornado 50, its a little annodized blue or purple box, though there are some yelllowy gold ones floating around in the stalls. 

50A forward, 20A reverse, 6-10 cells BEC enabled so it should replace your mtroniiks, also its plug and play, no set up buttons to faff around with, just a simple on/off switch.  I run one with my Najade and its 100% waterproof

[malcolmfrary]

Some motors are just plain unsuited to model use, and it sounds like these are some.  They are probably intended for use with a mains power unit with control via a heavy duty switch unit.  Measure the current at startup without an ESC, then you will know why you are dumping them.