Are Deans enough?
 

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.

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.

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...

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

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.

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.

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

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:no:

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

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.

Contact them. They are probably 5V fans anyway.

JEff

My dad's name is Dean. :eyes:




I think bullet plugs would be nice if you really wanted to spend the money to upgrade them and replace all your connectors and adapters, then take the time to solder. I think deans are fine personally and I like them because they are pretty much the standard plug of high powered RC equipment.

How long have you been using that dean connector?Older plugs can cause more resistance.You could also try Astro Flight Zero Loss Connector

The link you posted was for some DDR memory, but I looked it up and the specs are lower than Deans. They state that they have less resistance than an equiv. piece of 14 gauge, Deans lists the same as 12Ga.

Jeff

The plug I'm using (was using) on my ESC wasn't too old. And it wasn't getting noticeably hot, certainly no warmer than the battery. I'll do some testing when I get my MMM fixed up and back in play.

LOL to many window open at the same time :lol:. My good pc is in the shop being fixed & I was thinking of getting a new one.Link fixed now

hi,

you can continue guessing...

...or go to this page, it might be the answer for your questions (it's NOT a shop):

http://www.elektromodellflug.de/hoch...romstecker.htm

it's in german, but at least you can read the figures.

I would call this guy a guru regarding RC-Electronics (chargers, batteries etc).

I have just ordered myself some golden 5,5mm plugs, and some fat 6 mm² cables (especially for motor-esc).

flo

Let's all buy Lehner gold connectors! :lol:

Resistance: <0,05mOhm
Continious: >250A

yeah, and after that I'm broke & cant't afford lipos... :lol:

the 5,5 mm bullet plugs I've bought are affordable, u get them for around eur 2,60 a pair.

but yes, it's worth to invest in good connectors.

They cost 3 euro for 1 pair :rofl:

I never gonna buy such expensive connectors. For me: "Wannabe/Chinese" Deans and Hobbycity 5.5mm Goldconnectors :yes:

they're the plugs for the motor cables. for the batts I keep deans, at the moment. I 've learned that the real "deans" are better then the chinese copies.

I want the plugs this week and not by September... I' don't order 4 bullet plugs in HK...:rofl:

The real deans are gold plated. The copies aren't. Maybe this explains y the real deans are better?

These plugs look exactly like those zero loss plugs for audio speakers that i have used more than ten years back.

yep, and the metal spring/the thing that tightens the fit, is also different. the chinese has a "flat" one, the deans has a "curve", which are easier to plug in. after 2 years of use, the deans have lost their gold plating. I think there are different qualities within "chinese" deans. left the chinese, right the original (at least I think so...):
http://s6b.directupload.net/images/0...p/29mspqmf.jpg

bullet connectors all the way! 6.5mm can hold 200amps

The biggest concern I have with bullet connectors as battery connection is that even if you heat shrink them they will never be as safe from shorting as deans/trx plugs. Only way to solve this is to find some type of plastic casing that the bullet plugs fit into, similar to the HC Turnigy packs

That's what EC3 and EC5 connectors are...

While I think Deans are "ok" for most applications, I also think they should be upgraded so they are around 50% larger in all dimensions.

But aside from that, those huge currents are only a problem on take-off or heavy acceleration from a slow speed. Normally, current levels are around 15A or less on average. So, I guess it depends on what kind of driving you do. If you do continual standing backflips where there are a lot more heavy current draws, then maybe a different connector is in order. If you are racing, you generally aren't as hard on the system (as far as burst current is concerned) because you try not to stop and go as much, and so Deans are more than adequate.

I personally don't like bullets for two reasons:

1) They are not polarized so accidental hookups to the ESC can be catastrophic. Yeah, You could put a male on one batt wire and a female on the other, but that leads to point #2.

2) Ease of shorting. Even properly insulated female bullets have a relatively large exposed area where a conductor could conceivably make contact. Not worth the risk.

I suppose you could do something like this to eliminate connector woes:

http://scriptasylum.com/forumpics/large_connectors.jpg

hahaha Brian

btw, where did you get that? Looks like an electric pack plug.

I think I got it a partsexpress.com. It was intended to make my old car audio amp rack easily removable, but I went in a different direction and didn't need it after all.

Works really well in my XT8 conversion though. That connector is good for 600v and 150A, so perfect for a really HV setup.

I saw those on the site where you can buy powerpoles from. I didn't know how big they were till I read the specs on them. Massive 0.0

that's F*cking hilarious Brian... haha.. looks like the connectors they use for electrical lift trucks.. I know some of the big trains uses Pole connectors 10 times the size of that. . just plain awesome...

:lol: Is that connector on your charger too?

i just put one male and one female bullet on my pack and one female and one male on the charger, then i use electrical tape on the exposed areas when racing. Issue solved

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

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. :rofl:


Jeff

I used one in my high powered car audio system a few years back. Had it in a Grand Cherokee, I wanted to be able to remove it easily. It also made it easy to hook up my power inverter in the back of the jeep. At the time I built electric motors for a living and got them through work.

All you have to do it put one male and one female on the battery and vise versa for the ESC. You would have to be careful when you are storing them tough because something could bridge the gap and poof...

I'm getting some Hyperion bullet plugs because if you wanted you could easily run a series or parallel setup.