Anyone ever use these connectors?

[Spartanator]

Anyone ever use these connectors?

Travis, next time you run the 34" V bring your temp gun. Get readings on the connectors, packs, pack leads, motor/ESC leads, motor and anything else that could be warm.
You were probably going to do some of that anyways... Lol

[kevinpratt823]

I can say this, check out some really fast builds....I can assure you not many are using 6.5 bullets. If any at all are using them. Just sayin...

At this level I'm at now, I'll agree that it's better to have too much than not enough. Same rule I go by with almost everything I do. You can tell this by most of my builds. Pretty much every one has more motor and Esc than it needs. Better to over do it than under do it. You know this too.....

FWIW, Keith Bradley recently told me he ran 5.5mm connectors in his old S-cat record boat, granted it's a twin, but it is a really fast build.........
I have had a few connections desolder in the past, and the worst offenders were not the ones that drew the most current or had the highest voltage, actually it is the opposite. It would be my Whiplash20, because I hold it wide open for most of the time it is out, so there is more time for the heat to saturate the connector then melt the solder. It is also only 4s, so it is using a higher current to do the same amount of work as say a 6s with a lower kv for equivalent rpm.

Personally, I would just go with some 8mm bullets if you're even questioning it. I also now tend to lean more towards the Castle 8mm bullets, as there is more mass to them to absorb the heat, where the ones I used to use were pretty thin around the solder cup, so the solder takes the heat real quick.

[kfxguy]

Travis, next time you run the 34" V bring your temp gun. Get readings on the connectors, packs, pack leads, motor/ESC leads, motor and anything else that could be warm.
You were probably going to do some of that anyways... Lol

Funny you say that. I went picked up a pocket temp gun on lunch today. I had a larger one but it was a pita to carry with me. I forget it a lot too. This one will fit in my prop box.

[kfxguy]

FWIW, Keith Bradley recently told me he ran 5.5mm connectors in his old S-cat record boat, granted it's a twin, but it is a really fast build.........
I have had a few connections desolder in the past, and the worst offenders were not the ones that drew the most current or had the highest voltage, actually it is the opposite. It would be my Whiplash20, because I hold it wide open for most of the time it is out, so there is more time for the heat to saturate the connector then melt the solder. It is also only 4s, so it is using a higher current to do the same amount of work as say a 6s with a lower kv for equivalent rpm.

Personally, I would just go with some 8mm bullets if you're even questioning it. I also now tend to lean more towards the Castle 8mm bullets, as there is more mass to them to absorb the heat, where the ones I used to use were pretty thin around the solder cup, so the solder takes the heat real quick.

I won't say anything about Keith's cat because I know nothing about it. But. I am running a mono that pulls a good bit more current to go 90+ mph than my Rivercat did. I never had a failure in my Rivercat except when I plugged 8s into a seaking 180 and attempted to make a run. I've logged up to 399 amps (not consistent tho) in my logs. I'm just trying to over do things as I usually do. Seems to be working for me.

On a side note.....is it beneficial to use silver solder? If so, what kind exactly?

[complacent_one]

This is not true at all. Amps are amps, and 100 amps through a conductor creates the same amount of heat at 7.4v as it does at 44.4v, that is why there are no wattage ratings. An 8mm that is good for 300 amps at 12s is still only good for 300 amps at 2s.
Though it is questionable about how they are rated, because it also depends heavily on the type of solder that you use(and how well you solder), as that will be the point of failure, and also the duration of that current bursts and the length of the run.

You are correct, been a while since I worked in the field, as i was mixing current usage with ampacity of given conductors.

In the end the voltage is still relative, since we are dealing with DC. Since with lv DC the voltage drop is much higher over a given distance. As voltage increases the percentage of drop decreases. In other words, the working load (since we are driving a motor) also decreases. Typically connections and conductors have the Ampacity, or heat load based of of the sq rt of max x 2. The fact that these connectors are based on max is simply amusing. All things considered, the solder connection is the most likely point of concern in a circuit since it is the easiest to invoke human error. If you look at the material, mass and surface area for conduction on a 6.5mm connector to say 10ga or even 8ga, it would be hard to argue that the connector itself is the weak point in the link. In all actuality, the best way to combat would be to turn down copper rod and insulate for bullet connector use. Since you brought fuses into the conversation, I have a couple of 300AMP fuses in my truck with 1/0 cable for my audio system. When getting after it, i am passing about 175-200 amps through the fuse and that is through a cross section of about 3sq/mm. Has not let go yet.

But back to the point. Travis, i certainly agree in overbuilding and we have, indeed, had that discussion. But there is also the law of diminishing returns. Bigger connectors and larger primary on the batteries certainly would not hurt.

[kfxguy]

You are correct, been a while since I worked in the field, as i was mixing current usage with ampacity of given conductors.

In the end the voltage is still relative, since we are dealing with DC. Since with lv DC the voltage drop is much higher over a given distance. As voltage increases the percentage of drop decreases. In other words, the working load (since we are driving a motor) also decreases. Typically connections and conductors have the Ampacity, or heat load based of of the sq rt of max x 2. The fact that these connectors are based on max is simply amusing. All things considered, the solder connection is the most likely point of concern in a circuit since it is the easiest to invoke human error. If you look at the material, mass and surface area for conduction on a 6.5mm connector to say 10ga or even 8ga, it would be hard to argue that the connector itself is the weak point in the link. In all actuality, the best way to combat would be to turn down copper rod and insulate for bullet connector use. Since you brought fuses into the conversation, I have a couple of 300AMP fuses in my truck with 1/0 cable for my audio system. When getting after it, i am passing about 175-200 amps through the fuse and that is through a cross section of about 3sq/mm. Has not let go yet.

But back to the point. Travis, i certainly agree in overbuilding and we have, indeed, had that discussion. But there is also the law of diminishing returns. Bigger connectors and larger primary on the batteries certainly would not hurt.

1) have you ever looked at the contact patch between the make an female connectors? I'll show you tonight. It's not as good as you'd expect.
2) I installed car audio for over a decade professionally. Was mecp certified. So I can relate. Comparing an amp and a surge circuit to a constant circuit (as in a motor at full throttle) isn't hardly the same. Really the only time in an audio system your going to pull massive amounts of current and at a constant rate is in a competition. Hence the addition of more batteries close to the amp and MUCH larger caps and wires. I also have never connected power cable to my battery with bullet connectors. The fuse comment, a fuse will pass the amount of current it's designed to pass. Hence, the reason for a rating on it. The conductor is very short also. Extend that conductor to a foot or more and see how long it lasts. Your better off with a circuit breaker in your instance anyway.

When your considering mass of the connector, it isn't just that to consider, it's more important to consider the contact area. That's why some smaller high quality connectors do better than larger, cheap Chinese connectors. Like I said, this evening when I get home, I'll try to take a sharpie to a few connectors and show the contact area. If I can.

I just put an email in to john so I can see what he says about larger wire on the revo batteries. That would be awesome.

[Luck as a Constant]

Huh?
"Scratches head"
This thread just went way over my head.
Bravo...

Hope the ...uhmm... Connectors work for ya.
Have fun guys -)


Sent from my iPhone using Tapatalk

[complacent_one]

Travis,

Not trying to muddy your thread man, I too was MECP First Class working on Master back in '94-'95. I have done breakers and fuses.....so i get you there, and i also understand the breakdown between a static load and one seen in Car Audio. The thermal breakdown on that fuse comes at a certain point, the fireworks inside the fused protective barrier are base on the voltage.

i agree the contact patch is not great, but would be better on an 8mm connector compared to a 6.5mm.

In either case, my conclusions are based on theory, because I have not build near or plus 100mph FE Boats...you have and many other people here, so I will kindly step back from the conversation.

Oh yeah... good luck, you have already blown away expectations on that mono!!

[kevinpratt823]

I remember reading somewhere a claim that some of the smaller bullets actually have more contact area than some of the larger, it may have been 5.5mm vs. 6.5mm due to the extra length of the 5.5mm, but that is also dependent on weather or not most of that length actually makes contact......just speculation but food for thought. I'd love to see resistance readings from a low range high resolution meter though.

Silver solder is definitely beneficial, as it has a higher melting point than common lead based blends, and I believe a stronger mechanical bond. I did a bunch of research a while back when I was decididing how to best prevent solder failures, but I forget a lot of it now. The jist of it though IIRC is this-

Lead solders are listed by percentage of tin/lead. The higher the lead content the higher the liquid melting point, but I believe there may have been other drawbacks, maybe conductivity.
Lead free was tin, silver, and some had copper, higher silver/copper content had higher melting points.

I believe the more common leaded solder is sn60pb40, with a liquid point of 374 deg F. I ended up buying the Novak 3% Silver(just because it was conveniently available), which I believe is sn97ag3, which is closer to 430 deg F. It is noticably different to work with in that it requires more heat, it also tends to be harder to judge a good joint because even the good joints haze over.

In a quick search I came up with this charthttp://www.kester.com/kester-content/uploads/2013/06/Alloy-Temperature-Chart-15Feb11.pdf"]http://www.kester.com/kester-content...rt-15Feb11.pdf[/URL], but the info is out there if you want to learn about the different ingredients and their properties, there was also a decent thread on here somewhere.

[tlandauer]

I don't want to muddy this excellent discussion, but have one quick question for Kevin:
I too noticed the higher liquid point solder hazes when cooled and was always doubtful of my joint, also, with these , how much do I need to worry over heating the component. i.e., if I solder 8 ga. wire, I have to really heat it up for a proper tin, and these higher melting point solders worries me . Any advice you can give me?
Thanks in advance...

[kevinpratt823]

I don't want to muddy this excellent discussion, but have one quick question for Kevin:
I too noticed the higher liquid point solder hazes when cooled and was always doubtful of my joint, also, with these , how much do I need to worry over heating the component. i.e., if I solder 8 ga. wire, I have to really heat it up for a proper tin, and these higher melting point solders worries me . Any advice you can give me?
Thanks in advance...

I know what you mean, but truthfully I can't give you a definitive answer as most of the time I learn limits the hard way and I have yet to ruin a component from soldering. I can tell you that just considering the way it works, think of it like doing an inlay, you have one shot and the longer you mess with it the worse it gets lol. On more concerning joints, I tin the wires first then let them cool, then tin the bullet and keep it hot, bringing the wire down to it and once it melts keep the heat on the whole connection to let it even out then pull away before too much heat has a chance to travel too far. The longer you take, it also allows the solder to flow up the wire and reduce flexibility too. If I get concerned I will pull it all apart and let it cool then start over, but the more times you do that the farther up the wire the solder travels........ Minimizing the duration of heat to the component wire and doing it all in one shot is my philosophy, and it has worked for me so far, but I'm sure others may have their own ideas as well.

[tlandauer]

Thank you very much Kevin, it is very helpful, I will keep these points remembered!

[kevinpratt823]

399 amps, yikes lol. What you have been doing certainly has been working for you, I'm just trying to contribute to the discussion. The only reason I brought up Keith's cat was because he used it as a reference to me recently on my build, and to point out the different requirements of different applications, which you are obviously aware of. For the sake of the technical connector/fuse discussion, consider that there are also different types of fuses for different applications, such as "fast acting" and "slow blow" or "time delay". Fuses/breakers actually have 2 ratings- "inverse time", whereas it will sustain a current close to or just over it's limit for a given time before it blows(oval racing?), and also "instantaneous" where it takes a very high spike typically well above it's rating, to blow/trip instantaneously(SAW?). This is pretty much the same case as the connectors and much of the other components in our toys, and that's why we get away with what we do when we dance on that fine line.
At the end of the day, the higher resistance of a connector causes more heat which triggers failure of the solder. The available solutions are lower resistance connectors and higher melting point solder. For me, that has come to mean the higher mass Castle 8mm bullets and the Novak 3% silver solder as my best option personally for higher current/longer duration setups.

And if you want to have a laugh at my expense, this is what happens when you're not paying close attention to the (4) 5s packs your hooking up to a paralell charge adapter. "Bullets- You're doing it wrong"
SAM_0654.jpg

[kfxguy]

I drew on a connector then plugged it in and unplugged it. Gives you an idea of the contact area where the sharpie rubbed off. Might put this better in perspective for you.



image.jpg

[kfxguy]

399 amps, yikes lol. What you have been doing certainly has been working for you, I'm just trying to contribute to the discussion. The only reason I brought up Keith's cat was because he used it as a reference to me recently on my build, and to point out the different requirements of different applications, which you are obviously aware of. For the sake of the technical connector/fuse discussion, consider that there are also different types of fuses for different applications, such as "fast acting" and "slow blow" or "time delay". Fuses/breakers actually have 2 ratings- "inverse time", whereas it will sustain a current close to or just over it's limit for a given time before it blows(oval racing?), and also "instantaneous" where it takes a very high spike typically well above it's rating, to blow/trip instantaneously(SAW?). This is pretty much the same case as the connectors and much of the other components in our toys, and that's why we get away with what we do when we dance on that fine line.
At the end of the day, the higher resistance of a connector causes more heat which triggers failure of the solder. The available solutions are lower resistance connectors and higher melting point solder. For me, that has come to mean the higher mass Castle 8mm bullets and the Novak 3% silver solder as my best option personally for higher current/longer duration setups.

And if you want to have a laugh at my expense, this is what happens when you're not paying close attention to the (4) 5s packs your hooking up to a paralell charge adapter. "Bullets- You're doing it wrong"
[ATTACH=CONFIG]131142[/ATTACH]

This is one of the exact reasons I want a protected type connector!