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Old 09-20-2005, 11:29 AM   #16
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Remember that measuring resistance with an Ohm meter is good. But you can not really judge a conector how well it does conduct until you measure the voltage drop. That means to power the circuit and have current flowing.
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Old 09-20-2005, 12:00 PM   #17
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Exactly. Measuring the voltage drop is the only way so you can calculate the resistance in this area. Using an Ohmmeter doesn´t work at such low lowresistance things.
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Old 09-20-2005, 12:11 PM   #18
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@ Barry
I know there are 2 differnt Tamiya connectors but the motor connectors may be better but also are not good.
What you´re talking about may be right for the cheap copies but the original Corally connectors are made by Swiss company MC who invented that connector technology. They don´t use springsteel.
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Old 09-20-2005, 12:49 PM   #19
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Hi,

Biggest thing that the corally connector has going for it is the very big surface contact area which is around the whole inside diameter of the tube. The deans connector is a flat surface and you need extra solder joints for the wire and the tamiya connector.... Ok lets not even bother talking about the tamiya connector it's a waste of time. I was never a fan of direct solder because it's a pain in the butt anf you keep heating up the outside cells which is not good for them. Comparatively speaking there is so much more losses in the wire that there is much more you can do by working on your wiring.

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Old 09-20-2005, 01:42 PM   #20
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Writer's preface: I claim superior knowledge of electricity to absolutely NO ONE. I barely know ohm's law.

I'm just guessing, but ***IF*** we're talking surface area as being key to the least resistance: with power pole/Corally connectors, you do have the whole inside of the tube, but then you only have a small, very thin line where the tubes touch the battery contacts, don't you? This is what the ESC sees as the battery connection, not the tubes...right?

If that's the case, it would seem something like deans plugs (pic below) or power pole connectors would offer the least resistance. However, you now have as many as four solder joints between the battery and the ESC as opposed to only two with power poles/corallys...but it still seems like more surface area.

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Old 09-20-2005, 01:45 PM   #21
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Those are some nice looking Deans connectors. Where are all the melt spots?
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Old 09-20-2005, 06:55 PM   #22
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gibbous,

you are assuming that the deans connector surface will be completely flat and you will get perfect contact over the whole surface area... This is not going to happen, those little bars are stamped out (or maybe cropped) and when you stamp (or crop) a part out of a sheet of metal it will bend.

In high frequency application the electricity does something called "skinning" it flows at the outside surfaces and on the edges, with the corally connector you have a lot of "edges" and the little splines are designed to flatten out and give more of a contact area as it's pushed into the tube.

Another interesting tidbit I heard - take a piece of wire and measure the resistance. Cut the wire, solder it back together and measure the resistance again. With the solder joint the resistance will be 14 times higher. I have not checked this myself, but it cam from a telecommunications design engineer whose opinion I trust.

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Old 09-20-2005, 09:03 PM   #23
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Chris most guys on this forum have meters that are unable to measure in the mili-ohm. So we would not be able to see such a comparison.
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Old 09-20-2005, 09:08 PM   #24
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dodgeguy,

I think someone mentioned it earlier but it's really all about voltage drop. yes this is very closely related to resistance but if you have more volts at the motor you have more motor rpms.

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Old 09-20-2005, 09:11 PM   #25
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Yes I know about Voltage drop. I was the one to post about it. I was just making a point about the info your engineer friend had said.
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Old 09-20-2005, 11:47 PM   #26
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Just slap deans on and use the quick battery swapping to allow you to run more packs before the track closes.
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Old 09-21-2005, 09:58 AM   #27
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I question the the connection between the tube and the surface of the battery. There may be excellent contact between the insert and the inside of the tube, I don't dispute that at all. But the contact between the tube itself and the battery seems like it wouldn't be very signficant at all, seeing as how the actual contact "patch" is probably no wider than the line a ball point pen makes.
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Old 09-21-2005, 11:31 AM   #28
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Quote:
I question the the connection between the tube and the surface of the battery. There may be excellent contact between the insert and the inside of the tube, I don't dispute that at all. But the contact between the tube itself and the battery seems like it wouldn't be very signficant at all, seeing as how the actual contact "patch" is probably no wider than the line a ball point pen makes.

Gibbous,

Thats what the solder is for. Big contact patch of solder to tube and solder to cell.

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Old 09-21-2005, 12:50 PM   #29
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Quote:
Originally Posted by crimson eagle
Gibbous,

Thats what the solder is for. Big contact patch of solder to tube and solder to cell.

Chris
Okay, but you just got done telling us how important edges are to a connection. And I do buy that theory, but why does it not apply to the connection between the tube and battery? There are very few edges in the contact between the side of the tube and the flat surface of the battery terminal and solder doesn't conduct nearly as well as wire would. Seems to me it would be better to have several strands of wire (providing more "edges") covering more of the terminal's surface, held in place by solder rather than just one, thin edge of a tube touching the terminal surrounded by gobs of solder. Correct me if I'm wrong....
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Old 09-21-2005, 01:18 PM   #30
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I see where you are going here. If you have a large contact patch with a large cross sectional area then you therefore must have a least a decent sized circumference "edge" which goes all around the oustside of that. The edges become more important when you do not have a large contact patch, most people these days like to run serrated or drilled brushes. The current can transfer to the com through all of the edges of the brush which is in contact with it. This is the theory anyway and it does seem to be borne out by results.

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