melting wires!?!?!? - RC-Monster Forums

jokerjustin · 08:11 PM

i usually run my revo in my track next to my hose every morning before i go to school. well today i wasnt running it hard and when it passed by me i saw a large puff of smoke!!

instantly i ran unplugged my battery and tried to find where the smoke came from... i had directly soldered my motor to my mm and some of the "replacement wire" i used was bubbling and melting all over the place. the wire inside was completley black. its weird ive been using this exact setup for bout 2 weeks straight and ive run it waaaaaay harder than this morning... and thoughts on why this suddenly happened?

Finnster · 11.08.2007, 01:34 PM

Prolly a bad solder connection. It may have been bouncing around, breaking up a bit, then got to a point where the resistance got high. Add lots of current and presto, magic smoke machine.

That or it was too small a wire, maybe a short, but I vote bad connect.

jokerjustin · 11.08.2007, 08:11 PM

well something happened i now fixed the wire with good quality wire and now its cooging alot and i seem to have lost my brakes completly.... what happened?

Finnster · 11.08.2007, 08:23 PM

uh oh, possible motor damage?

DrKnow65 · 11.08.2007, 08:37 PM

Sounds like you lost a leg of the motor? (one of the three wires is not connected from the esc to the motor) have you checked the other two wires that were not "smoked" mabey one of them is at fault. Possible the wire is desoldered inside the can? (heat will conduct out of the wire to each end) if you have a voltmeter you could check the motor circuit at the esc board, take the two screws out of the esc and lift out the boards, use your meter to check the ohms between the three solder joints connecting the motor wires to the esc. They should all read 0-ohms to each other (like when you touch the tester wires togeather). Does the esc smell burnt inside? Any think look burnt?

jokerjustin · 11.08.2007, 09:54 PM

no nothing looks burnt.. i may have messed up the wires coming out of the motor though.... i dont know im still looking into it.... it will run one i get it rolling... but now the esc and motor get hotter alot faster than they used to..... i will test out the ohms right now.

MetalMan · 11.08.2007, 10:35 PM

Could also be that some FETs in the ESC blew. During the MM beta the motor I was supplied with caused two MM ESCs to fry some FETs. They both still ran, but there was a LOT of cogging.

jokerjustin · 11.09.2007, 11:07 AM

i just have a feeling that its the motor for the fact that i lost my brake... it will brake but just ever so slightly...... i know that feigeos are not the best quality motors but this happend all of a sudden. its never seen any hard hits or crashes just running on a little track with about 1 foot fumps around so i dont know what happend... does feigo offer a warrenty? ive had this motor for about 1 month and i think it should have lasted me longer than this......... i just opened the mamba max and it looks fine i took off the heatsink and all the fets look ok... no black residue or burnt smell.... i plugged it into my mamba 8000kv and it runs it fine with no heat or smell........ i just dont get this

:grrrrr r:

DrKnow65 · 11.09.2007, 11:30 PM

did you test the motor leads while you had the esc open?

jokerjustin · 11.10.2007, 12:52 AM

yea one of the guys at my lhs did and he said that the black and red combo gave a wierd reading.. it showed and extremly high resistance compared to the rest. im in the process of talking to mike about this to see how i can get back up and running!

DrKnow65 · 11.11.2007, 11:23 AM

The wires inside the motor can are just "butt" soldered togeather to the winding leads ( the wires are just touching end to end then soldered )

When I replaced my motor wires I used desoldering-braid to pull all the solder out of the winding leads (where your silicone covered wires attach inside the motor) once the solder was gone, I frayed out the winding leads and pushed the deans wire into it so they were intertwined (like if you put your two hands togeather with your fingers pushed through eachother) Then I used a single strand of wire to wrap around the frayed out connection to pull it all back togeather (this makes a mechanical connection, you could pull on the wires a bit and they would stay in place, like if someone wrapped a shoelace around you interlaced fingers it would be hard to get your hands apart)) then I soldered the connection. Just keep in mind this is a difficult opperation because it all happens inside the can. It takes a high wattage iron (at least 40watts- I used a gun that was 150watts) and you'll have to use heat shrink inside the can too so you'll need somthing better than a bic lighter... if you do it just make sure the wires are the same size as the originals and they are pointed the right way befor you solder them or else you'll have problems routing them out of the can properly. I used deans 12 gauge wet noodle and modified the can a bit with a dremel tool to give them room to get out and heat shrinked them where they exit the can to avoid shorting out if they got banged in to.

Of course this voids any warranty so if you have the warranty option I'd go there first. I like avoid dealing with warranty stuff myself and would rather fix the problem so it dosn't happen again (if you get a replacement motor it will be built the same way and may happen again)

If you do decide to change the wires you'll have to open the motor up which is another adventure you'll have to prepare for as well (the screws are lock-tighted-in and you'll have to heat them up to carefully remove them). Not sure this is the best option for you, depends on your experience-tools-available help-ect...

jokerjustin · 11.11.2007, 02:18 PM

i will try this as a last resort... i really want to get my car back and running. thanks for the great walkthrough drknow.

it just frustrates me that this happens.. i take great care of my car and i try to avoid these problems.