Model Boat Mayhem
Technical, Techniques, Hints, and Tips => The "Black Arts!" ( Electrics & Electronics ) => Topic started by: jaymac on May 05, 2012, 07:43:23 pm
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Ho Today for some reason after about 15mins running .When I opened the boat up to switch off found the battery connector supply to the ESC in meltdown this is only the 3rd time I have run the boat (not new ) and no sign of that before . Only thing I thought of was perhaps water shorting it out bur would have thought that would have caused other problems .Main thing is how do I l the melted connectors and what can I use to reconnect alas not much length on the tail from the ESC . keep it simple please newbie
Thanks
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You can cut off the plastic insulation, uncrimp the connectors and use a simple chocolate block type connector.
For replacement you could fit banana plug/socket.
The probable cause was heat generated through a poor connection something like the female end becoming a bit loose or you are pulling very high current.
Bob
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Tamaya connectors are only suitable for up to about 20 amps. Some chinese esc s which have a far higher output also use them. For a quick fix use a choc block. The plastic screw fix block as sold by B@Q etc. Deans type connectors would be fine but would need soildering. John.
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Hi,I have found that those type of connectors are prone to do what you have found. The tubes tend to enlarge hence the poor connection. Suggest you use Deans type. Nemesis
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Go on to the component shop website and get the yellow jobbies that they sell far better than those poor inferior quality Tamya ones
http://www.component-shop.co.uk/html/connectors.html
The ones that are XT60
dave
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Thanks all for the input I'll try the choc blocks first
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It might be worth checking the current consumption of the motor as well.
Easy if you have an ammeter.
Bob
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I'm with Nemesis, Deans connectors are hard to beat and very reliable, I use nothing else.
Peter.
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Re ''It might be worth checking the current consumption of the motor as well.
Easy if you have an ammeter.''
Could I do that with a multi meter and its two motors dont know what they are though the 2 spare are Johnsons
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SOME Johnson motors on 12 volts can pull horrendous current. It would help to identify these motors.
Do you have a fuse in the battery supply cable?
This would give an indication of the current under load.
It depends if the multimeter is self switching for higher currents.
Bob
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Most multimeters including auto ranging ones have a separate terminal (pos) through a shunt for high current.
To be safe ensure the meter is set for max current before connecting.
Ned
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And most of the multimeters only read 10A max
Regards Ian
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As far as I can see there is no ID on the existing motors anyway connected up today and found one motor wont run also noticed that the prop shaft can move back and forth about 2 maybe 3 mm and the nut on the Huco coupling can slide about .Cant find any info on how these work . Thoroughly cheesed of as the whole point of getting ready to go is Fingers Knackered and unable to fiddle much .
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Most digital multimeters only claim up to 10A, but some will read up to 19.99A. Safest way, if there isn't a known good meter around is to sacrifice some fuses, either work up in value until they stop blowing, or work down until they start. Boxes of various value auto type fuses can be got cheaply on market stalls and similar places.
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OK I got the motor running looks as if there is a duff connection/dryjoint somewhere could that have contributed to the meltdown? . For some reasson this setup is wired as follows ESC mounted on Pegboard that has 2 pairs of spade terminals . the (+) lead to one terminal pair with lead of the other half to the motor tehn from the other pair one + lead to the other motor . I.m guessing the spades are connected underneath the board and thats wher the fault is
The (-) lead is just split into two to the motors . would ther be any reason for the complicated Positve lead arrangement
I'll New Post the Loose Shaft query in the correc section
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the simplest way to wire the ESC to the motors is to use a chocolate block type connector.
The 2 motor outputs from the ESC on one side.
The individual motor connections on the other.
You can either put 1 wire in, 2 out to the motors or simply bridge the ESC wires to the next contact and wire each motor wire individually.
Bob
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Sadly fuses are not used by many members. Id rather a fuse failure than something more costly. John.
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Sadly fuses are not used by many members. Id rather a fuse failure than something more costly. John.
It's hard to tell from the OP's writing, but I wonder if they're underneath the pegboard??
jaymac, any chance you could post a piccy of the 'pegboard and wiring??
Mark.
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Bob yes that sounds simpler though his way was quite tidy
Mark I said I thought the connections were wired underneath .I'll see if I can take a PIc Oh dear more battery charging
John
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OK here (hopefully are the Pics of above the pgboard and below the pegboard the Arrows are the connection point and the loose end .Could this have assisted my Fryup
(http://i152.photobucket.com/albums/s161/jaymac_port/PEGBOARD.jpg)
(http://i152.photobucket.com/albums/s161/jaymac_port/pegboardUnderside.jpg)
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A dry joint would have reduced the current, and thus the power available to melt the connector.
I would go along with the suggestion that one or more of the female pins in the melted housing had had its diameter increased. This would reduce contact pressure and increase resistance. The bit with the increased resistance would then be the bit that heated up.
Always worth checking for dry joints, though. Remaking suspect ones helps reliability, as well.
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Hi John,
I understand now :embarrassed:
Okay, if you number the spade connectors from the top 1-4, then 1 and 4 are the red power leads from the esc, (1 is connected to 4 underneath and the broken connection should be connected to the one you thought :-)) wow that's a lot of 'connect's). 2 and 3 are the power leads to the motors and are connected 1-2 and 3-4 via the fuses. The black's don't need this separation so are just split from the blue wire from the esc.
As the fuses are rated at 20A it may explain why the Tamiya connector gave up the ghost.
I see various connectors have been mentioned as replacements, well if you ask 10 modellers what they use you'll probably get 10 different answers ok2 Any of the 4mm bullets or 4mm blades will be okay :-)) they're all rated at around 60+A
Mark.
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What fuses Mark I dont see any
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There are 2 x Car type blade fuses on the end of the board.
The way that is wited means that the ESC CAN be subject to 39 amps constant without a fuse blowing if the power is equally distributed.
Mt advice would be to fuse the input to the ESC at below its rated current.
If you want to fuse each motor I would suggest 1/2 of the ESC curent.
If it was mine I would simply rip it all out and wire individually and just fit blade fuses where you want.
I never trust others wiring anyway and always do this for my own piece of mind.
Bob
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What fuses Mark I dont see any
John, the two yellow things plugged into the spade connectors are what are known as 'blade type fuses' and are usually found in cars.
Mark.
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Thanks mark I thought they were just a botched up attempt at Insulating .Am thinking of redoing just using choc blocks
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I would also consider NOT using tracked Printed circuit boards to carry large currents.
ken
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I would also consider NOT using tracked Printed circuit boards to carry large currents.
ken
Me either I think Veroboard is rated at about 2A@12V and the "Copies" probably less
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Thanks Ken anything wrong with just using choc box connector
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None at all, I use these in most of my boats.
Bob
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Thanks Bob of course you mentioned that earlier silly me trouble is this old brain is addled twixt this and my shaft problem
John