adding extra bullets between esc/motor

[ozzie-crawl]

in the next few months iam about to start a vs1 conversion to electric.
i notice everyone runs the esc wires threw the rear bulk head (hope thats the rite term)
iam wondering how much resistance is created if a 5.5mm bullets were epoxied into the bulk head then the esc can plug into those on the inside and motor on the outside,just looking at making it more water tight and easy esc removal.
i have noticed esc,s like shultz dont run motor wires straight to the esc but have bullets soldered straight to the board adding extra bullets.
any thoughts-comments appreciated
scott

[Jeff Wohlt]

No differnt han all the kill wires I see across the pond. Seems it would work well.

[egneg]

I don't see any problem with this as long as the area that carries the current is the same or more than the wire used. Poor contact or not enough area is what causes heat and problems.

[ozzie-crawl]

thats good news :banana:
do you think 2 bullets soldered back to back and a small piece of brass tube over the join would be okay

[sailr]

I have been thinking of doing precisely what you are proposing. I see no problem with it other than you now have twice the possibility of bad connection and extra resistance.

[JimClark]

What about a piece of brass rod to solder the two onto?


thats good news :banana:
do you think 2 bullets soldered back to back and a small piece of brass tube over the join would be okay

[BakedMopar]

You could possibly use a female with the ends cut off and drilled through then use both sides motor/esc male and just plug in.

Oh i see ozie had the sMe ideA

[ozzie-crawl]

do you think the added resistance will be a consern?
just think it will be so much easier to swap out esc,but my main concern is keeping the hull water tight.

[sailr]

???

If we could find 5.5mm I.D. brass tubing we could just use brass tube and then male on both esc and motor to plug into it!


You could possibly use a female with the ends cut off and drilled through then use both sides motor/esc male and just plug in.

Oh i see ozie had the sMe ideA

[ozzie-crawl]

???

If we could find 5.5mm I.D. brass tubing we could just use brass tube and then male on both esc and motor to plug into it!

i was thinking the same thing,only problem i see is it may not be water proof

[ozzie-crawl]

maybe if we go female each side and a solid brass rod going threw the bulk head?

[sailr]

You got some 5.5mm rod?

[hydromaddicted]

why would'nt you just pass wire through the bulkhead with connectors on the ends?

[PatrickM]

If you have the ability to cut e-ring grooves in 5.5 female connectors, you can adapt this setup for your situation. The first pic shows the modified connector. the second shows the female connector held in place by the e-rings. I use this setup as an emergency cutoff on a few boats.
http://img.villagephotos.com/p/2006-5/1185150/Grooves.jpg
http://img.villagephotos.com/p/2006-5/1185150/looptop.jpg

[ozzie-crawl]

You got some 5.5mm rod?

NO,but at work we have 10mm,could have it machined down but leave a flange in the centre that butts up to bulkheadi think the easiest way would be 2 females inside a piece of brass tube

[ozzie-crawl]

patrick, not a bad idea but i need to run 3 close to each other with out them shorting

[PatrickM]

Replace the e-rings with snap rings..... much smaller OD.

[ozzie-crawl]

patrick are they water proof like that, its a very clean look

[PatrickM]

Depends on the hole tolerance..... I've not had a leak that I can attribute to the connector passing through the plate, but if its a concern you can seal it with RTV. I use this as an emergency cutoff. To pass motor wires through the plate, I use 3/16"x5/16" (~5x8mm) silicone grommets. Shrink tube to increase the wire diameter (if needed), and the grommets, are installed before soldering the connector on the wire. 5.5 connectors will easily fit through the 5/16" hole in the plate and the silicone grommet is flexible enough to slide into the hole with the wire in place. Neoprene grommets are a different story. Here's a pic of the installation on my VS-1.


http://img.villagephotos.com/p/2006-5/1185150/grommets.jpg

[properchopper]

This thread has me re-thinking the pass-through issue. Next build I'll solder the "notched-style" connectors together and pass and JB seal them, with the female exiting on the rear of the box. Looks like it'll work & clean up the install.

[PatrickM]

Counting connectors is not the same as counting laps, Tony.....:olleyes:

When it comes to connectors, less is better.... none is better than one, one is better than two, etc.. The car guys hard wire their setups for a reason... because it is more efficient... and it is a noticeable difference, in cars anyway..... The performance difference isn't as noticeable in our boats because of all the driveline and other variables, but I still try to minimize the number of connections. The only reason that we don't hardwire our boats is for convenience, and speaking for myself, I'm just too damn lazy!

Now that I've shot my mouth off, Tony will put a double connected boat together and kick my butt with it!.... LOL

[properchopper]

Counting connectors is not the same as counting laps, Tony.....:olleyes:

LOL

Here's the deal Pat. I went out and bought a lap counter !! Now, if you kick me in the nuts everytime you complete a lap I'll click the counter . Should work ! :o

[properchopper]

I measured the resistance of a mated pair of 5.5 connectors. If I did it right { I haven't mated anything in a long time :eek:}, it was 0.20 ohms. An equal length of 12 gauge wire was also 0.20 ohms. Seems that adding an extra pair of connectors in-line shouldn't matter. :noidea:

[properchopper]

Actually, once the meter stabilized, the wire resistance was 0.10 ohms. Still probably not a big deal.

[Alfa Spirit]

A bullet connector isn' t a problem especially with 5,5mm pk, the best choice and you can spay a KF contacts will be better

[PatrickM]

The only way to accurately measure the resistance of connectors is with a precision bridge/shunt setup.... and even the laboratory data is not always an indication of how the connector will perform at high current flow. If your 2/10ths of an ohm (0.2x6 for dual connectors between ESC and motor) DVM measurement is accurate, those who have written connector comparison articles for the magazines are full of bull..... a couple of these articles claim 0.001 ohms for Deans connectors and we all know that a high grade bullet is much better than a Deans. Yeah I know....:blah::blah:

Alfa, I'm not familiar with the KF brand connectors, but for high amp setups I try to stick with LMT or BK brands.... they seem to have a more precise fit than most of the other brands.

[ozzie-crawl]

iam looking at it this way,on the vs1 setups a lot a people are using the stock ul1 motor/esc.if iam rite the origonal setup runs 2x deans to the battry wich get swapped out for a single set of bullets,how much resistance is removed just from that.
have a look at the shultz 40/160s they dont have the motor wires soldered directly to the esc but have bullets soldered directly to the board adding a pair of bullets.
i realize less is better but in real world conditions is it really going to make any diffrence :confused2:
i think i will do the same as tony femal to male joined then epoxy in to place
it will be water tight and so much easier to remove esc.

[BILL OXIDEAN]

The only way to accurately measure the resistance of connectors is with a precision bridge/shunt setup.... and even the laboratory data is not always an indication of how the connector will perform at high current flow. If you're 2/10ths of an ohm (0.2x6 for dual connectors between ESC and motor) DVM measurement is accurate, those who have written connector comparison articles for the magazines are full of bull..... a couple of these articles claim 0.001 ohms for Deans connectors and we all know that a high grade bullet is much better than a Deans. Yeah I know....:blah::blah:

Alfa, I'm not familiar with the KF brand connectors, but for high amp setups I try to stick with LMT or BK brands.... they seem to have a more precise fit than most of the other brands.


Perfect info, i've been thinking about resistance and plugs lately and wondering where I should get super high quality units. I trust LMT, I was gonna use Neu

[Jeff Wohlt]

Neu plugs are China as well.

[BILL OXIDEAN]

Neu plugs are China as well.

Thanx Mr. Wohlt I suspected that..

[ozzie-crawl]

i was wondering the same thing.my plugs are either from OSE or HK
does spending more $$$ on plugs make a diffrence ? or is it a name brand thing?

[BILL OXIDEAN]

Sport dosen't matter, but SAWS plug resistance can cost you 2-3mph

[ozzie-crawl]

yea iam onlly running sport setups around 100-120a max.
i can see if guys are racing or running s.a.w it can make a diffrence

[PatrickM]

It wouldn't surprise me to learn that the LMT and BK plugs are made in China also. If they are, the manufacturers were carefully chosen by the brand vendors and held to higher standards than the manufacturers of the garden variety connectors.

It's true that the Schultze 40/160 uses plugs soldered directly to the circuit board, but this ESC also utilizes two parallel wires and plugs for each of the three motor connections. Two plugs in parallel cuts the resistance in half... the instructions also state that the wires from these motor side connectors should be soldered directly to the motor. Same with the battery side.

As Wilmer said, quality connectors can make a couple of mph difference in SAW racing.... can you afford to lose 4-5mph by doubling your connectors?

The bottom line is that it all depends on your application.... sport or racing...:smile:

[properchopper]

Man, I never realized how much contribution connectors can add [or subtract] to the mix. Has me rethinking some of my setups. Wire length also. And 4S2P adaptors as well. Two questions : Who sells which brand of connectors ? I've been using the OSE 5.5's & recently got some (with the "soldering-friendly" notch)
from CBP when OSE was out of stock. LMT or BK or what ?

Would the bigger [8mm] connectors be the way to go ? ( quite a re-soldering task) :unsure: Maybe just for P-powered race setups ?

Good topic - thanks for your input, Pat.

[Jeff Wohlt]

It is hard to believe any 3-5 mph can be lost to decent plugs vs really good plugs. Now real crap plugs I could see.

We have gone from Deans to gold plugs and short wires what else???

I guess if I were running saws I would not have plugs... if it were that important. Direct soldering is what I would do.

[PatrickM]

As an example of the difference that a few milliohms can make, I'll use my VS-1 with spec UL-1 motor and ESC...
With an Elite 5000mah 4S1P 35C pack I was able to drive the boat flat out around the course, no throttling in the corners. I switched to a pair of TP 5000mah 2S 40C hard case car packs and with no other changes had to start lifting off the throttle in the corners because of the extra power. The difference was the cell IR's.... about 18 mohms for the Elite pack vs. 12 mohms for the two TP packs in series.... also need to factor in the extra resistance of the connector between the pair of 2S packs. Other racers in our club have noticed similar results from the lower resistance of the newer generation Lipos.

[egneg]

What about solder and the wire size/connector fit. I would think this would be more of a concern than the number of 5.5's in series.

[PatrickM]

Excellent point.... when soldering smaller gauge wire into larger connectors it's a good idea to wrap the wire with copper desoldering braid to fit the ID of the connector. Copper has less resistance than solder. The newer style cutaway connectors make this less of an issue because you can somewhat conform the wire strands to the inside of the shell to increase contact area.

[Jeff Wohlt]

I can understand the lipo issue and lower IR. But connectors is very small...now lets stay straight on what we are talking....good connectors of at least 5.5 vs the German connectors that say they are the best. You do pay more for better gold and how long they last until resistance begins to increase....after 50 connections is the gold now down to the inner metal? This could be a big issue. Deans is the same....wear the gold off and you are down to possible some crap metal.

You can also spread the wire into a mushroom where all the wires are touching the connector before solering. But I was always told the best is one twisted tight and filled with solder to the connector.....well not if the wire tip is touching the plug only...seems like not as much true conection. I want that connector to carry the load as one unit so seems to me spreading the wire out is better...but I am told not so.

Good thread.

[PatrickM]

I can understand the lipo issue and lower IR. But connectors is very small...now lets stay straight on what we are talking....
Resistance (or impedence, if you prefer) is resistance..... in a DC series circuit resistance is cumulative, whether it is 2 milliohms of connector resistance or 2 milliohms of battery internal resistance.... Assuming that cheap bullet resistance is in the 1 mohm range (I've heard they can be more and that the higher quality conns less than half that, but I hate to quote numbers without backup data :olleyes:) for each connector in a DC series circuit, you will negate a 1 mohm advantage gained by upgrading your Lipos. Per my previous post, a 5-6 mohm reduction in battery IR shows a noticeable performance improvement with a spec setup.
On the other end of the speed control it's a marginally different situation. Here your dealing with a pseudo AC (actually pulsed DC) current adding frequency to the equation which can affect connector impedence... for the sake of simplicity it's probably better to ignore this factor, it doesn't make much of a difference. Resistance is still cumulative.

[bigwaveohs]

You could possibly use a female with the ends cut off and drilled through then use both sides motor/esc male and just plug in.

Oh i see ozie had the sMe ideA

This is exactly what I did on my VS-1 FE conversion only I soldered the wire into each end for a permanent extension and it works just fine.
Adding extra bullet connectors means one more connection to pull apart, corrode & etc...JMHO

[TRUCKPULL]

I think using good electronic solder is just as important as good
5.5mm plugs.

Regular solder will add more resistance then good electronic solder

Larry

[Jeff Wohlt]

Thanks, Patrick....great detail.

I think we have answered the question....can a person do this on a sport or posssibly a race set up? Sure you can. If you are a SAW runner then you already know what you should do.

Good thread...I have a set up or two that can use this config.

[sailr]

and what is electronic solder compared to, uh, regular solder?

[Jeff Wohlt]

The reason I like as much in contact with the wire and bullet as I can.

Certainly I would use the best electronic solder I could. I use regular radio shack solder for electronics but beats me if resistance is lower.

Why not silver solder? Would that not be better than all the tin in others?

Deans solder is suppose to be good but who knows....probably radio shack quality anyway...LOL.

[PatrickM]

I've been using a Kester 62/36/2.... it's 2% silver like the Deans.

I like it 'cause the joints stay shiny instead of turning dull like a lot of solders... :olleyes:

Problem is the stuff is 3 times the price of a good Kester 60/40... $65 for a one pound spool. Since it takes me about 5 years to go through a pound, the next time I buy a spool it'll probably cost $300 or so.... looking at it from that standpoint, $65 is a bargain! :laugh:

[BILL OXIDEAN]

I think using good electronic solder is just as important as good
5.5mm plugs.

Regular solder will add more resistance then good electronic solder

Larry

AMEN!!! you're absolutely right, I use only the best solder commercially available for the hobby industry Novak.

I used to swear by Deans, but have always been curious about some solder used in the stereo hi fi industry that bears tons of silver, and has ultra low resistance
WBT. After looking at their work, I wonder if they make 6mm connectors (that's what I use) I would definitely get them. They're out of germany and their rca jacks are made from highly ductile "OFC" copper 52pct these guys appear to be the "resistance busters"

http://www.parts-express.com/pe/showdetl.cfm?partnumber=093-584&source=googleps

Combine low resistance solder with high quality low resistance connectors, wire your system efficiently (cut all excess wire) and I PROMISE you will see a noticeable improvement over a basic system. You may find all sorts of benefits from more runtime to lower temps, more punch, its an all around great thing. I won't even contaminate my solder joints with 'run of the mill" solder you will always see me with Novak solder. It actually smells better than others, but I do NOT recommend takin' a whiff of it lol

http://www.parts-express.com/pe/showdetl.cfm?partnumber=093-584&source=googleps

[properchopper]

I've been using a Kester 62/36/2.... it's 2% silver like the Deans.

I like it 'cause the joints stay shiny instead of turning dull like a lot of solders... :olleyes:

Problem is the stuff is 3 times the price of a good Kester 60/40... $65 for a one pound spool. Since it takes me about 5 years to go through a pound, the next time I buy a spool it'll probably cost $300 or so.... looking at it from that standpoint, $65 is a bargain! :laugh:

I've been using this stuff - Qualitex [62/36/2] from the local electronics store. Flows great & stays shiny. $ 34.99 / lb. I always dremel my (solder) joints smooth to eliminate hot spots.

[PatrickM]

Combine low resistance solder ...... you will see a noticeable improvement over a basic hardwired system.Damn, Wilmer, your enthusiasm never fails to amaze me!... LOL
Maybe I'm misreading your statement, but how can you beat the resistance of a properly done hardwire setup?

[BILL OXIDEAN]

Damn, Wilmer, your enthusiasm never fails to amaze me!... LOL
Maybe I'm misreading your statement, but how can you beat the resistance of a properly done hardwire setup?

Yeah, you're right LoL I meant I meant like a run of the mill setup.