bullets getting hott!

[dana]

lately ive noticed my 5.5 mm bullets on my battery to esc connections have been getting too hot. im running two 2s 40c 5000mah packs. seaking 180, leopard 4074-2200kv motor and m445 prop. the motor has the 4mm connectors that it came with. those get pretty hott too... so today i lost one of my 5.5 to the batteries. i fished it in and as i suspected, the connector had melted off. the motor was pretty darn warm too. my question is, are the 5.5's my problem or should i change the motor connectors? i keep the motor connections wrapped with electrical tape, which were melted together. why is it so hott in there?

[LarrysDrifter]

How are the temps on the motor and esc? I've had bullets get hot, but only when running large props getting greedy with speed and running the boat too long. I only use HK 5.5's on the motor connection and HK 8mm on the battery connection no matter the boat set up. You may have to prop down a bit or maybe try a 6s set up to draw slightly less amps. I wouldn't tape the wires together either. You can make a wire loom from zip ties to keep them neat looking and prevent the motor bullets from touching. I'd also put the 5.5's on the motor side too. I think what you have now is too small. Usually, installing larger bullets won't help anything, but you can try it. If it doesn't help, I'd think about the set up.

[dana]

Well this setup was recommended as a solid setup that would run cool. I'm using venom bullets which are probably rubbish to begin with. I grabbed sum castle bullets for motor, so hope it helps. I don't tape motor connectors together, I individually wrap each connection.

[LarrysDrifter]

You should use shrink on the bullets, not tape.

[ron1950]

id make sure that the water is flowing through the cooling tubes without any obstructions also.....my t120 had to be drilled out as the makers didnt finish the job lol......i also have been told the m445 is the way to go but if it is getting hot enough to melt solder a smaller prop may be the way to go...what run times are u getting?

[dana]

larry, i am using tape over the shrink wrap, so you can imagine my frustration here. the motor connections just seem really weak. ron, the cooling tubes are working great! besides with this motor i shouldnt even really need cooling, but its there without problems

[dana]

run times, prolly 3-4 mins. today was about 3 when it melted off.

[Diesel6401]

That motor can pull some serious amps, I have been running CC6.5s on that motor and esc in my pursuit. I bought some HK 6.0mm bullets and to be honest I really really like them. http://www.hobbyking.com/hobbyking/s...idProduct=5281

[m4a1usr]

lthe motor connections just seem really weak.

Thats not helping. All connectors need to be tight. Depending on quality, and even how clean they are, you must ensure that they fit tight. I have to bend the prongs on my male bullets occasionally. Bullets in any size need to fit very tight. Not just easily slide together or apart. Just another one of those maintenance issues we should all get in the habit of.

John

[Diesel6401]

That's a good point John about the fit.

There is 2 different part number for HK 5.5mm bullets one set sucks the other set is ok. Ray S knows which ones are which, but I been digging some ebay 5.5mm bullets, I have the seller saved really REALLY nice connectors. Those 5.5s from ebay and the 6.0mm from HK have a VERY tight connection just like the CC bullets do.

On the left is the not so good 5.5mm from HK (i ordered the wrong ones), next are the ebay 5.5mm very nice good fit and clean look, 3rd is the HK 6.0mm Bullets slowly becoming my favorite really REALLY tight fit just like the CC last on the far right is the standard CC6.5.

I have slowwwwwly been converting my motor/esc connections over to the 6.0s on most of my other setups. The higher amp setups i run CC 6.5 or the 8s

[dana]

Well I can say that the motor connections slide off really easy, with almost no effort. I know it's a weak point, but will thus help my battery connections run cooler?

[LarrysDrifter]

Dana, I think your bullet heat issues come down to inadequate bullets and prop size and the boats attitude on the water. Try higher quality, larger bullets and maybe a slightly smaller prop or moving COG back some.

[properchopper]

Thats not helping. All connectors need to be tight. Depending on quality, and even how clean they are, you must ensure that they fit tight. I have to bend the prongs on my male bullets occasionally. Bullets in any size need to fit very tight. Not just easily slide together or apart. Just another one of those maintenance issues we should all get in the habit of.

John

Absolutely correct, Sir. An issue too often overlooked and worthy of note. I often need to insert the end of a tiny phillips-head screwdriver into the end of my males to spread out the tangs to make they fit the females with more tension. Tighter fit = more conductivity and less heat.

One thing I've noticed is that there's considerable variation in brand offerings in the 5.5's I get. In the picture, from left to right : a $20 for ten pairs connector;
a $3.97 for ten pairs connector; and another $20 for ten pairs connector.

The one on the left is long and smoothly machined ; the one in the middle is long and has a rougher-machined mating surface (which in the macro sense gives less mating surface) ; and the one on the right is smooth but shorter. I'm relatively sure (given that I have no empirical data to back this up) that there are differences in conductivity and heat generation between these.

Something that perplexes me is why the price difference between these. Anyone ?

Incidentally, I just bought a small butane torch and made a jig to melt off the soldered wires from the many dozens of used connectors I have in my dead electronics pile allowing me to re-use all these lonely and neglected pieces.

[dana]

tony. the one in the middle looks like my battery connectors ( not a fan of the maker ) and the ones on the right appear more like the ones i just purchased for the motor. they are very tight compared to whats on there now. ill start with my x442 and check temps

[properchopper]

I just searched 5.5 bullet connectors on ebay and saw many different choices. I'm just a little confused as to which are the best; there's quite a price variation and one would imagine that the more expensive ones are better, but is this really the case ?