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Author Topic: motor running at full throttle  (Read 5552 times)

Mike0001

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motor running at full throttle
« on: May 23, 2015, 08:15:58 PM »

hi

just charged up my pb battery on my fishing boat and for some reason it now runs at full power only ?

transmitter for some reason have no effect what so ever

someone enlighten me please

boat has been running fine for nearly a year
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Neil

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Re: motor running at full throttle
« Reply #1 on: May 23, 2015, 08:20:33 PM »

don't know what system you are using but I have had the problem in the past..........and rectified it by resetting the ESC....on most 27 and 40 MHz systems there are two set screws in the  speed controller whereby one centres the device and then the second is for increasing  and decreasing the revs............but I had to set the transmitter to centre first..
a very small screw driver or even a tooth pick sharpened to a screw driver blade will do.

neil.
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Mike0001

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Re: motor running at full throttle
« Reply #2 on: May 23, 2015, 08:39:44 PM »

27mhz

centred the esc as you said stopped the motor running but now the rudder tries to move, twitches the servo to rudder 1 or 2 mm, still no response now from transmitter on either rudder or motor ?.......... very odd

only 1 screw on speed controller though plus and minus sign on it
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malcolmfrary

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Re: motor running at full throttle
« Reply #3 on: May 23, 2015, 09:01:38 PM »

Knowing exactly what ESC is involved and what the power arrangements are will help greatly in trying to diagnose the problem

Some of the symptoms described so far are what can happen if there is a bit of damp in the works, doing its evil during a winter store.
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Mike0001

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Re: motor running at full throttle
« Reply #4 on: May 24, 2015, 01:55:30 PM »

well was not built by me but from what I can see

12v pb battery

esc says protech pro 35

batt with minus and plus sign down left edge, motor with minus and plus sign down right edge

has text saying 3-4 sec... under that 6-10 nc

standard servo.... not sure on motor

30amp esc and 2 x 3.7 amp hour 6v  gell cells,these are linked together to give 12v
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malcolmfrary

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Re: motor running at full throttle
« Reply #5 on: May 25, 2015, 10:28:00 AM »

If its this one, I haven't found much about it apart from the picture that google turned up on a Norwegian vendors site.  It says it can handle up to 10 cells NC (probably NiCad), so OK for 12 volts.  The picture indicates a 5 volt BEC that can handle up to 3 or 4 servos.
The other more or less relevant hits were threads on other hobby sites, with comments showing mixed experiences of the brand, rather than anything specific about that particular ESC.
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inertia

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Re: motor running at full throttle
« Reply #6 on: May 25, 2015, 03:54:19 PM »

It does rather sound like a main power FET failure, in which case the only place for it is the bin. Before you do so just check that the channel you're using does work properly by trying a servo in it, or trying the ESC in another channel.
DM
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Mike0001

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Re: motor running at full throttle
« Reply #7 on: May 25, 2015, 05:42:50 PM »

malcolm its most definately the one  pictured

inertia new to this what is fet ?

so you guys reckon new speed controller needed ?
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Hellboy Paul

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Re: motor running at full throttle
« Reply #8 on: May 25, 2015, 05:52:13 PM »

Field Effect Transistor.


Paul.
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inertia

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Re: motor running at full throttle
« Reply #9 on: May 25, 2015, 06:51:39 PM »

malcolm its most definately the one  pictured
inertia new to this what is fet ?
so you guys reckon new speed controller needed ?

Mike
It's the expensive gizmo that switches the power on and off very rapidly, thus varying the speed of the motor. If it dies then the motor will stay at full "on". My recommendation, assuming you've tried the tests I described, would be to replace the unit. If you have a fishing boat then it's unlikely you need a 35A speed controller.
One plea - buy British (Electronize, ACTion, Microgyros etc) but avoid the blue ones sold as "50A Forward/20A Reverse". They have a poor reputation for reliability.
Dave M
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malcolmfrary

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Re: motor running at full throttle
« Reply #10 on: May 26, 2015, 09:12:05 AM »

Mike
It's the expensive gizmo that switches the power on and off very rapidly, thus varying the speed of the motor. If it dies then the motor will stay at full "on". My recommendation, assuming you've tried the tests I described, would be to replace the unit. If you have a fishing boat then it's unlikely you need a 35A speed controller.
One plea - buy British (Electronize, ACTion, Microgyros etc) but avoid the blue ones sold as "50A Forward/20A Reverse". They have a poor reputation for reliability.
Dave M
What he said, plus I had one of the "50/20A" types in a boat that decided, one day, to head off all by itself at full speed.  Fortunately it found a sloping bank to ground on.  Unfortunately it was concrete, and by the time I got to it it had reprofiled the 30mm prop to a 20mm one.
The plastic sleeve on the ESC might redirect splashes, but it is probable that damp air could get in and stay in and create on of mother natures extra circuits.  The same might be true of the servo mentioned.
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Mike0001

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Re: motor running at full throttle
« Reply #11 on: May 26, 2015, 08:21:48 PM »

so how do you work out what amperage to go for on the esc ?

why did builder of this one go for 30 amps?

thanks for replies really helpful    :-))
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malcolmfrary

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Re: motor running at full throttle
« Reply #12 on: May 26, 2015, 09:44:32 PM »

Thats the advantage of brushed motors - you can test them without an ESC.  Hooked direct to a battery, one will spin.  Under load (prop in water), the current taken can be measured, either by using a multimeter on Amps or by test blowing a series of fuses.  When you know what current it wants, multiply by 2, and pick the next value up.
The nice thing about modern ESCs is that since generally what will handle a lot will handle a little, so close matching is not really an issue.
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Mike0001

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Re: motor running at full throttle
« Reply #13 on: July 22, 2015, 06:06:26 PM »

going to reinstate this thread as its causing me a headache

further investigation ... set up is 2 6v batteries

really not sure what the esc  is as its unbranded but from ebay ad for the boat its 30 amp... it did come with a spare esc

took out the esc to have a better look and as you can see wired differently..... when switched on the  rudder twitches and then goes to full throttle..... I became a member of wicksteed park boat club recently so might bring it along and ask some kindly members to have a look for me

also would like to find about motor cooling system ?  as far as I can see water is sucked in from underneath goes through tubes over motor and out side vent ?   would like to learn how that works

its a nice boat but i have never ran it yet but would love to get it going

could take more pics if any interest  :-)

so pics to show the esc and my problem... for one, no on/off switch lead ?

original one is red one



would firstly like to know is this a suitable replacement  ( realise its a cheap esc but it came with boat and is brand new )


secondly the cooling system

how does this work ... how does it manage to suck in the water etc

inlet ? it has a cut out on front section to scoop in water ( I think)




the two 6v batteries linked



the cooling system ? with three metal tubes I take it soldered on top ?



a lot of questions I know but I am learning and hope it may help others as well

cheers for now

mike  :-))




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John W E

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Re: motor running at full throttle
« Reply #14 on: July 22, 2015, 06:37:58 PM »

hi ya Mike

the yellow one with Mystery written on it - is for a brushless motor.  I have the same speed controller in a drawer soldered to a brushless motor.   By looking at the motor in the model that, to me doesn't look that it is brushless - nor does the red speed controller.   Both of them look like brush motors.  if its the red speed controller which is running at full throttle, it may indicate that the output transistors are 'fried'.   Then again, it may be wired up wrongly.    I presume you are connecting the red plug (Deans plug) to the batteries?    Also, the 2 wires with the bullet connection should go to the motor.

I would also add that looking at the rest of the photographs, especially the one with the propeller, it should be sorted out with a proper propeller added. without the aid of all the nuts and bolts and spacers.   It would aid in the model performing better.

aye
john
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Mike0001

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Re: motor running at full throttle
« Reply #15 on: July 22, 2015, 08:40:02 PM »

hi

yes its the red one which came out, any links to get then a suitable replacement for the red one, want to stick to same sort of build as it was as cant really justify spending a lot on it knowing it may not work.

Problem I have is I don't have a brand or anything so can I just search for brushed  30 amp esc ?

I will pop some pics of rest of boat, its certainly got me learning a lot and its an interesting build  :-)
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Mike0001

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Re: motor running at full throttle
« Reply #16 on: July 22, 2015, 09:17:40 PM »

also wiring was as you said, deans plug to battery, 2 bullet connectors got to motor..... think it may be a duff esc and this is just something thrown in as part of deal

so if I buy a 30amp brushed motor esc and try that all should be well........ I will be back on this thread when it arrives

thanks for advice
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malcolmfrary

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Re: motor running at full throttle
« Reply #17 on: July 22, 2015, 09:43:41 PM »

Unless its a truly ginormous prop, I can't really see it loading any motor up enough to cause it to need cooling.  As mentioned earlier in the thread, to check the current draw of the motor, wire it up to the battery via a fuse and resistor.  Place in water and hold, switch on, change value of fuses until you find two values where the lower blows and the higher doesn't.  Use the higher value fuse, base your choice of ESC on that fuse value by doubling it to give a safety margin.  As bluebird says, a proper prop will be much better.
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Mike0001

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Re: motor running at full throttle
« Reply #18 on: July 23, 2015, 05:23:45 PM »

I think that first pic of prop made it look bigger than it really is

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malcolmfrary

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Re: motor running at full throttle
« Reply #19 on: July 24, 2015, 10:01:48 AM »

The lack of discernible pitch, blunt edges and odd texture of the prop indicates that while it will spin round, it will do little in the way of moving the boat forward by moving water backward. 
Unless the motor is a totally unsuitable wind (super-dooper ultra sport sort of language) and intended to run on a much lower voltage the cooling arrangements can be safely dumped, and the holes in the hull sealed.  The right combination of prop and motor for the size, shape and intended performance will result in better use of the power in the batteries, and longer run times.
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inertia

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Re: motor running at full throttle
« Reply #20 on: July 24, 2015, 10:14:05 AM »

There are a lot of points about this boat installation which would raise my eyebrows, but unless Mike wants a list of them then I'll restrict my observations to one - that's a very strange shaft coupling, mate. It looks for all the world like a drill chuck. If the motor has been taken out of a battery drill then it's likely to be a very fast-revving type (drills having high-ratio gearboxes) and thus will get very hot and draw lots of current when put on direct-drive in a model boat. I'd venture that if you were to fit a 'proper' prop then the thing would get even hotter. No motor in a fishing boat should require any amount of cooling - certainly not that much.
Any chance of a picture of the whole model, along with a value for its overall length? We might be able to suggest a better motor/prop combination - and PLEASE get rid of that electrical choc-block connector!
DM
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Mike0001

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Re: motor running at full throttle
« Reply #21 on: July 24, 2015, 11:28:38 AM »

hi all

Its certainly an interesting build, what I will do is start a new thread and you guys can pull it to pieces for me..... it did run well for a while and chugged along nicely, then it was stored for a month during may....... I came back charged up battery , turned it on and its on full throttle only

so anyway watch for new thread and hey I don't mind any comments inertia neg or good to me its interesting and learning all the time... isn't that what the forum is about

so off to take some pics  :-)
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spearfish99

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Re: motor running at full throttle
« Reply #22 on: July 24, 2015, 11:47:37 AM »

Hi Mike,

 Just a silly question, did you have a separate power source connected to the receiver?. As the speed controller has a BEC as part of it and would be supplying power to the receiver, if you connect a separate supply, it is possible to fry the rx to some degree.

  As a replacement, Could I suggest this.   http://www.ebay.co.uk/itm/221673488580?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
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inertia

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Re: motor running at full throttle
« Reply #23 on: July 24, 2015, 01:44:01 PM »

Spearfish
I don't think that one has reverse.
DM
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