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-   -   help bl noobie smoke no power! (https://www.rc-monster.com/forum/showthread.php?t=6647)

rampingray 05.03.2007 08:12 PM

help bl noobie smoke no power!
 
ok got every going and all it does when on the ground is shutter and start going slowly and the is smoke coming from under the heat sink is it a goner?

AAngel 05.03.2007 08:55 PM

Yeah, as they say, these things run on smoke and if you let it out, they won't run. If it's coming from under the sink, I think it's probably one or more of the FETs. That stuttering is called cogging and if you stay on the throttle while it does this it flows LOTS of current through the esc and things get very hot very quickly. My best guesses on the cogging are either a bad connection someplace, overgearing, driveline hangup, or sub standard batteries.

These are just guesses of course, but generally speaking, smoke is a bad thing.

rampingray 05.03.2007 10:31 PM

for batts i am running 16c 3300 gp's wired in series is this set up good or not?
i just figured out that for some reason the esc is only drawing from one batt? how does that happen?

AAngel 05.04.2007 12:34 AM

I'm guessing that you mean that you were running two 8 cell packs in series and it was only drawing from one pack. Is that what you are saying? If so, I don't see how it was drawing at all. If you were using a series connection between the packs, and there was a bad connection some place, you'd have an open circuit and no current would flow to the esc.

What makes you say that the esc was only drawing from one pack? If that is the case, then you may have mistakenly set the packs up in parallel; and, if that is the case, you may have been drawing more current than the esc could handle. IIRC, the GP3300 can dump some serious current when fully charged.

16 nimh cells in series is good for some pretty high voltage and there are a few that run that many cells. I just don't have any idea of the current that your setup will draw.

zeropointbug 05.04.2007 01:22 AM

How do you figure that it is only drawing from one pack? You said you wired the packs in series, correct? We need more info... :032:

rampingray 05.04.2007 08:12 PM

well only one bat got warm and after wards he warm bat read 2v when the other is 10v

A4DTM 05.04.2007 08:56 PM

pictures please

AAngel 05.04.2007 09:12 PM

Yeah, we need to see the adapter that you are using. It sounds a lot like you are using a parallel adapter and one of the battery connections is bad.

Patrick 05.04.2007 09:49 PM

Quote:

Originally Posted by rampingray
well only one bat got warm and after wards he warm bat read 2v when the other is 10v

2 volts?! That can't be good for an 8 cell pack, and shouldn't happen if it is wired in series.
Did both batteries have the same amount of charge left in them? (that shouldn't cause the smokey ESC though)
Is it the bk warrior 7018 with 9xl motor in an e-maxx that your talking about? Most people agree that a 70amp ESC isn't realy enough for a reliable e-maxx.
What gearing?
Does it roll freely?
This is the first time you've used it, isn't it?
Are you using an external BEC or a reciever pack?
Need more info and a picture of the adpter you used.

rampingray 05.04.2007 10:52 PM

http://i11.photobucket.com/albums/a1...IMAG0021-1.jpg

rampingray 05.04.2007 10:54 PM

i am using a external pack for the rx . it is the first time i have used it but not the first time it has been used. i am using a 28t pinion and the stock emaxx one

Patrick 05.04.2007 11:02 PM

Hmm, from that picture is looks like the packs are deffinately wired in series.

Patrick 05.04.2007 11:37 PM

A few more overly simple questions just to get it out of my head.
You used a RX pack, but is the BEC disabled?
Are the batteries deffinately soldered together correct? (+-+-+- etc, not ++ or --)
Were both of the packs fully charged or at least the same amount of charge left in themwhen you tried to use it?

Were you trying to take off in 1st gear or is it locked in 2nd? It is an e-maxx tranny isn't it?

If it is in 2nd gear then 66/28 gearing is overgeared I think (assuming stock ratio diffs) especially for 70 amp speed contoller. I wouldn't be supprised if that makes it cog and if you don't let go of the trigger once it starts cogging, that makes life hard for the ESC from the high amps spikes and will sometimes make them give up.

To me it seems like there is 2 problems, but I'm not sure if theyr'e related.
1. Smoke can out of your ESC.
2. One battery got hotter than the other and had a lot less volts after you used it.

rampingray 05.04.2007 11:57 PM

Quote:

Originally Posted by Patrick
A few more overly simple questions just to get it out of my head.
You used a RX pack, but is the BEC disabled?
Are the batteries deffinately soldered together correct? (+-+-+- etc, not ++ or --)
Were both of the packs fully charged or at least the same amount of charge left in themwhen you tried to use it?

Were you trying to take off in 1st gear or is it locked in 2nd? It is an e-maxx tranny isn't it?

If it is in 2nd gear then 66/28 gearing is overgeared I think (assuming stock ratio diffs) especially for 70 amp speed contoller. I wouldn't be supprised if that makes it cog and if you don't let go of the trigger once it starts cogging, that makes life hard for the ESC from the high amps spikes and will sometimes make them give up.

To me it seems like there is 2 problems, but I'm not sure if theyr'e related.
1. Smoke can out of your ESC.
2. One battery got hotter than the other and had a lot less volts after you used it.

yes the bec is disable and yes the batts are assembled right but i believe that the pack weren't charged equally it is in first when i start out
and 1 and 2 are correct

jhautz 05.05.2007 01:22 AM

The over discharged bateries may have limited the number of amps that the whole battery pack can supply and as a result of the low amp capability you get lots of cogging. Just like if you use cheap cells. they cant deliver the amps required and the system doesnt run right. Cogging is about the worst thing you can do to your esc and if you dont let off the throttle when it startes to cog you are going to tax that esc pretty hard. Also, as Patrik said, the 7018 is rather small for an emaxx and the 28/66 gearing is rather tall. All of these things combined and Im not surprised the esc was smoking. If the esc smells burt... it is burnt. I'd recomend getting at least a 9920 or the mamba maxx and you should be in much better shape.


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