Are Deans enough?

[Snipin_Willy]

I know this has been brought up before but after running this weekend I've got a sneaky suspicion that deans plugs are just not up to the 1/8 job we would like for them to be.
Could deans plugs be the weak link in an electrical system? I'm having trouble keeping my tekno neu cool. Last night it got up to ~185 after a full 20 min main. I was not going easy on it, but it's only geared for ~36. I don't think a Neu motor is suppose to get this hot under running condition. If the deans plug is causing some resistance under high amp draw could this be affecting the motor temp because of the voltage drop?
I think I'm going to try another connector type before I race again, a serious connector this time.

[littlegiant]

Originally Posted by Snipin_Willy

I know this has been brought up before but after running this weekend I've got a sneaky suspicion that deans plugs are just not up to the 1/8 job we would like for them to be.
Could deans plugs be the weak link in an electrical system? I'm having trouble keeping my tekno neu cool. Last night it got up to ~185 after a full 20 min main. I was not going easy on it, but it's only geared for ~36. I don't think a Neu motor is suppose to get this hot under running condition. If the deans plug is causing some resistance under high amp draw could this be affecting the motor temp because of the voltage drop?
I think I'm going to try another connector type before I race again, a serious connector this time.

Are you deans warmer than your neu?

I don't think that heat generated by deans can travel so far back up to the motor. Heat from the deans has to go through the esc then to the motor lead then to the motor to heat it up. What's the temp on your esc? Which truck were you running? The weight? Batts? I am too curious how a neu can get to that kind of temp.

[iTz Nicholas]

If you want you can use some 6.5mm bullet plugs. I'm going to switch to bullet plugs on my RC18T.

TRX connectors work fine in my BL erevo, the motor stays very cool. I agree with littlegiant, the heat from the deans cant affect motor temps. Do you have good airflow? My CC nue was always very hot until I cut a hole in the Body and lowerd the motor timing.

[iTz Nicholas]

http://www.allerc.com/product_info.p...oducts_id=4494

Get some of those, 140A continuous and 280A burst seams like it would be good enough for any application. I don't know if you will be able to get it in time for your next race though...

[E-Revonut]

Some people need to understand this a little better!!! He isn't talking about the deans plug heat being transferred to his motor!!! Plugs have resistance, resistance causes heat but it also causes a drop in voltage. A drop in voltage causes amp draw to go up, Amp draw going up increases heat! If voltage is dropping because of enough resistance and increasing amp draw it will heat up all components in the system.

I use deans on 1/18 stuff, I tried them on 1/8 and didn't like them. They do get warmer than my Traxxas plugs. The Traxxas plugs offer a lot more surface area than deans do, they also stay plugged together better and are easier to plug together in a rushed battery swap.

[J57ltr]

Originally Posted by E-Revonut

Some people need to understand this a little better!!! He isn't talking about the deans plug heat being transferred to his motor!!! Plugs have resistance, resistance causes heat but it also causes a drop in voltage. A drop in voltage causes amp draw to go up, Amp draw going up increases heat! If voltage is dropping because of enough resistance and increasing amp draw it will heat up all components in the system.

I use deans on 1/18 stuff, I tried them on 1/8 and didn't like them. They do get warmer than my Traxxas plugs. The Traxxas plugs offer a lot more surface area than deans do, they also stay plugged together better and are easier to plug together in a rushed battery swap.

Yes some people do. If the resistance is in line with the motor the voltage drop is not going to make the motor draw more current, it can't it's limited by the resistance of the leads and connectors between the ESC and motor. I=V/R so just because you add resistance to the circuit the current to the motor goes down not up. The only thing is that the motor would slightly more sluggish and take longer to reach speed.

The slower a motor goes the less impedance it has and the longer the current flows to the motor. As a motor spins the impedance is near 0 and as the RPM's climb the impedance gets higher and higher until the back EMF generated counters the voltage in and the motor reaches maximum RPM for the voltage given. That's why you see these huge spikes in current and then it starts to drop the faster you go the less current is drawn. This does not take into account the actual switching of the phases as they get faster and faster with less duration as rpm increases. But it's the same, even with a brushed motor.

If the deans are hotter than the rest of your wire then you might have a bad solder job or defective connector or you applied too much heat and moved the pin out of alignment and it's not making the best connection. I have done this before and had to slightly pull them apart for them to even make connection, and I used to solder for a living. If your wires and everything is the same temp then you are just drawing a lot of current. At these power levels some of us need 8g wire.


Jeff

[E-Revonut]

Ok so my explanation wasn't perfect, but he wasn't talking about heat from the deans heating up the motor! My deans weren't hotter than the wire, just hotter than a TRX connector.

[zeropointbug]

I think TRX connectors wouldn't be as hot because the thermal coupling to the connector casing is not as good... thereby making it seem like it's cooler. They are both essentially the same thing.

[J57ltr]

The funny thing is that nobody that has a high current connector has a rating for them. Before I found Deans I was going to use the smaller Anderson connectors, but I thought a 3.2" long connector was a little large. They are the only ones that have the proper specs as far as I am concerned (Amp derating curves and such, life cycle data you know specs.)

Like I said before he might have a bad connection. If you have a good meter like a Fluke Series 3 or above you can actually measure Siemens. Zero the lead resistance and that will allow you to measure conductance through the system without dealing with lead resistance. Lead resistance always gets in the way on measuring very small resistances.

Jeff

[Snipin_Willy]

Changing things up a bit, deans might be ok. But anything heavier I'd go to a bullet connector. After several hours of post race maintenance I've replace a bad bearing in the rear diff which was causing significant drag. I changed the wires from my motor to ESC from pig tails with 6.5mm bullets on either end to solding them to the motor wires and leaving bullets on the other end (reduced number of connections).
I can't hardly test anything yet because I'm waiting on my MMM cases from castle. My MMM case broken somewhere during the 20min main and my ESC was flopping around only hanging to the vehicle by the bullet connectors. I'm amazed it got me through the race. The fan is long dead (RIP).

Has anyone done any digging on where to find a 30x30x7.5mm 5v fan? the 7.5mm thickness makes it a very odd size and I haven't been able to find much for anything less than $12 each. These things shouldn't run more than $5

[J57ltr]

http://www.rcplanet.com/Integy_7_Fin..._p/int2902.htm

http://www.rcplanet.com/Integy_7_Fin..._p/int2903.htm

http://www.rcplanet.com/Integy_Cooli.../intc22479.htm

http://www.greathobbies.com/producti...d_id=INTC22479

Jeff

[J57ltr]

Originally Posted by J57ltr

The funny thing is that nobody that has a high current connector has a rating for them. Before I found Deans I was going to use the smaller Anderson connectors, but I thought a 3.2" long connector was a little large. They are the only ones that have the proper specs as far as I am concerned (Amp derating curves and such, life cycle data you know specs.)

Like I said before he might have a bad connection. If you have a good meter like a Fluke Series 3 or above you can actually measure Siemens. Zero the lead resistance and that will allow you to measure conductance through the system without dealing with lead resistance. Lead resistance always gets in the way on measuring very small resistances.

Jeff

That would be the Anderson connector I was talking about like I said I think 3.2" is a little big.

They also use them on battery powered forklifts and pallet jacks. I even see them used for hooking up power for the aircraft at my Dads work. They are pretty much the defacto standard in high current connectors.and that's exactly how I pictured it in my head.


Jeff

[Snipin_Willy]

Yeah I saw the integy fans in my searches, and for $5 it might be worth trying the 7.5mm version. But what is the fan speed going to be a 5v? Can't hardly use the 10mm version because they wont fit in the MMM case.

[J57ltr]

Contact them. They are probably 5V fans anyway.

JEff