Mechanical Crimping Large Gauge Wiring Harnesses

Ive been trying to address a way to reach out to thehigh current and high performace crowd with my harness service while making my job easier. Im was trying to gauge how you guys felt about mechanical crimping. I found some 8G mechancial crimp splices. I figure it could take 4 12g or 10g on one side and one 8G on the other. These are technically used in fence building but i figure i could flux and solder to make a better connectionand then cover the entire joint with about two layers of heat shrink.

Here is a video that kinda explains what Im talking about..

[youtube]EYI4UpODxKU[/youtube]

I think you might find those running high powered setups, will be well experienced and making their own writing harnesses. Personally on an ebike I would never consider anderson connectors, I know others rave about them but imo they are far too' chunky'

KiM

Im seeing that and trying to get way from andersons myself. 4mm bullets are very nice and i like using them but im struggling on finding a method that parallels up to 4+ wires of multiple packs and this method would make it easier. Altho the pp75 are super bulky but they also solve this proble at a high cost. The pp45 only good for 2 12AWG. 6mm bullets could possibly do this also but it takes some heat to get solder flowing on connections that large. It was a thought and this could apply this proposed method whether it be small or large scale. Id rather over build it for less than slap a warning stating that this isnt for continuous duty on your 45A+ setup when using 45A andersons. I target newbies with low amperage setups that easily stay within the rating of the harness electrical limits and one plug for charging and discharging seems to work for them. Im kinda in the R&D mode to see where I can cut costs and improve quality to cater to a broader crowd.


One method im trying to prefect is bundling multiple wires with a fine strand of copper and soldering the hell out of it but there is so much wire wicking away the heat I need to look at larger irons or look at a crimping plate i could put around it and possibly use a propane torch to heat and let the solder wick in for a solid connection.

If you have crimpers with sufficient compression force, and the right shaped die in them for the particular shell or contact or whatever that you are crimping the wires into, it will essentially make it all one piece of metal (just like soldering should do), mechanically compression-welding the strands and shell together.

If the die or crimper isn't made for that shape, it may not compress evenly everywhere, and so some parts may not fully compress, and it might not be nearly as tough a connection as it should be. But if it is made for that shape and size, and has sufficient force applied, it'll work perfectly, without any kind of soldering.

Those crimp splices are aluminum, which won't take solder, and which will lose strength if you heat them enough to tin the copper wires inside.

You can get copper crimp splices and collars, though-- I've used them a lot for 1/16" to 1/8" mechanical cable joining. That would be a sound if chunky means of joining fat power cables.

Chalo

I've been happy with mechanical crimp copper crimp sleeves. I get em at the home center like Lowes or home depot. They are designed for crimping 110 house wire instead of uising wire nuts. They come in fairly big sizes, but at the home store, not big enough to splice two 8g lipo leads. I just shaved down the 8g wire till I could get both wires into the crimp along with a 12 g wire. Perhaps copper pipe for larger sizes?

As with all crimp stuff, done right it's good, done wrong it's no good.

I do the same as dogman. When I did my battery harness I was able to put 3 - 12 ga wires into one side and a 10 ga in the other. I crimped them a couple times with a regular small crimper then squished them good with a large pair of channel locks. Then finished up with my cheap $9 80w soldering iron and shrink tubing.

Home depot calls them 14 - 8ga copper crimp tube connectors.

Hi,

amberwolf said:

If you have crimpers with sufficient compression force, and the right shaped die in them for the particular shell or contact or whatever that you are crimping the wires into, it will essentially make it all one piece of metal (just like soldering should do), mechanically compression-welding the strands and shell together.

If the die or crimper isn't made for that shape, it may not compress evenly everywhere, and so some parts may not fully compress, and it might not be nearly as tough a connection as it should be. But if it is made for that shape and size, and has sufficient force applied, it'll work perfectly, without any kind of soldering.

Click to expand...

Those sleeves, which are designed to make a strong mechanical connection could actually separate the wires.

Those sleeves are used for steel cable... useless for high current electrical stuff. You need to use proper electrical fittings.

Also, for big wires you cannot hand crimp the connections. Even hammer crimpers tend to botch the job. I use a hydraulic crimper with 8-12 tons of squeeze. You can pick one up at your favorite Chinese Political Prisoner Slave Labor Tool Store for fairly cheap... they aren't the best, but will work fairly well.

Hydraulic crimp is the only way to go if you can afford a couple hundred bucks on a crimper.

liveforphysics said:

Hydraulic crimp is the only way to go if you can afford a couple hundred bucks on a crimper.

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Harbor Freight had a hydraulic hand crimper that works well for non-ISO9000 crimps for less than 50 bucks.
http://www.harborfreight.com/hydraulic-wire-crimping-tool-66150.html

But be careful of the HF crimpers--according to various people on DIY Electric car using them for large-gauge wiring, the dies in some (many?) of them are not the sizes they label them as, so you might need to experiment with the dies to get the correct crimping force and shape.


@MitchJi: I didn't see that pic of the sleeves in the OP; I guess I didn't scroll down past the vid. Those would indeed not be the right kind of sleeve to use for this, but I don't think I'd change what I'd said, anyway.


Regarding high-pressure crimpers, if you were willing to make your own stationary crimper, bench mounted, you could use a hydraulic jack to lift the end of a bar lever, with dies held at the other end of the lever, and the pivot point such that the force is mulitplied at the die end. I remember some sort of "pressure spot 'welder'" used to secure sheet metal together for boxes in shop class back in highschool that was made that way (though they didn't use a jack, it was purpose-built, it would still do the same job).

HF is backordered. There are a selection of various Hydraulic Crimpers on ebay. Any suggestions on what is good and/or not so good?

I dunno Alan this was a random thought. Are you thinking about following through with it.

I am thinking about getting one. Luke has one so it must be good. (But his is a better one...)

I picked up some of those crimp tubes about the time Dogman wrote about them. I've not used them but have wanted to, and I've been trying to figure out the proper crimper for them. Clearly soldering them the way you do the crimp itself is not critical. But I'd like the option of just crimping them properly, or perhaps crimping them properly and then soldering them.

To crimp them properly Gardner Bender calls for a GCP-5000A crimper which I haven't located. Perhaps it is a hydraulic crimper or a hand tool that was discontinued, but web searches failed to turn it up.

I did some experiments and found that my old WMR PowerPole ratchet crimper's alternate jaw set with a #6 uninsulated crimp die does a pretty reasonable job. It uses a single big "tooth" to crimp the tube and has a proper diameter half circle to support the other half. So that is probably good enough, especially if soldering is planned. This worked well on both the copper and steel tubes. Note also that the steel tubes took solder very well.

I also tried my coaxial hex crimper and it didn't seem to have enough power at all. I think hydraulics are indicated here.

In my searching I again came across this thread and checked on the HF hydraulic crimper that Dave mentioned. It is orderable but backordered. Then I checked ebay and found many crimpers there, which Luke and others had mentioned. So I'm considering getting one of the smaller hydraulic crimpers. They are about $65 plus shipping so not too bad pricewise and probably a lot better than the old hammer crimper I have used for battery cabling.

It it said that he who dies with the most tools wins. (probably because he will have the most friends wanting to borrow/inherit them).

Crimping is the best way to go as solder wicks into the wire and future vibration will try to break the wire at the wire/solder intersection. I made many cables for transit busses good for 300+ Amps no solder there. One needs to be sure, as others have said, the correct dies and lugs are used else it's a waste of time and money. Hydraulic crimpers are probly best but we used the regular 3' long brute force style. Always did a good job though. Some styles you hit with a hammer are cheap and probly would serve our purposes here but the Harbor freight units look acceptable as well. Do it right do it once. Oh and Andersons, Deans and barrels, are all great if you get the correct units for your amperage, install them on decent wire and provide the proper strain relief. Each has its own little niche where they do a bit better job than the other. I use mostly Andersons and barrels but have used the Deans as well and all are excellent products. Chalo mentioned the aluminum splices they are around as are lead, copper and brass splices and terminal ends. I like the plated copper stuff best it is strong , has a high melting point, and does not corrode easy.

I tested the West Mountain Radio PowerPole crimper with the alternate jaw set for 6 gauge uninsulated connectors. It seems to fit these 8-14 size Gardner Bender crimp tubes quite well, with the half circle supporting the tube while the square tooth makes a large indent. The brass colored unit is a steel one, and the rest are copper. They all take solder well. The steel are probably slightly stronger as they are somewhat harder to crimp.

In each of these crimped tubes are five wires. Four are #12 and the fifth is #10. These are rated for 3-5 #12's, so this is more copper than they recommend and thus VERY SNUG. The wires are locked in and don't pull out. One could solder the tip area beyond the crimp and perhaps avoid having solder wick into the wires, I haven't tried it. Short of a hydraulic crimper this is about as good as it is likely to get.

Along with this package of 50 crimp tubes I picked up some heavy walled shrink tube. It is much thicker walled than the usual electronics type stuff, it is intended for cable repair and so is more substantial. Of course there is also the type with glue in it. These crimp tubes should be covered by heatshrink, possibly a couple layers.

Imho, pick up a cheap stained glass soldering iron, and never look back. the one I picked up will do 2 awg wire to 12v batt terminals.

Alan B said:

It it said that he who dies with the most tools wins.

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With crimpers, it's he who tools with the most dies.

i cant risk a pull out so i gotta solder. Nice work Alan.

It would be easy to solder these at the tip, not as pretty as the way icecube does it, but good and solid.

A good crimp should not pull out, these fine stranded wires distribute crimping pressure well.

Solder is higher resistance than copper, good to crimp tight first and minimize resistance, then soldering after won't add resistance.

Lots of ways to do it.

Alan B said:

HF is backordered. There are a selection of various Hydraulic Crimpers on ebay. Any suggestions on what is good and/or not so good?

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It turns out that a lot of those Ebay crimpers (the ones in the red plastic box) are actually drop-shipped from Harbor Freight!

icecube57 said:

i cant risk a pull out so i gotta solder. Nice work Alan.

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Solder is not good. Liability for wicking-related failures.

If you have the option to crimp, crimp with a proper connector and a proper crimper (which can be manual or hydraulic), and you end up with a forged solid plug of copper all the way from the wire to the pin in the connector. Literally seamless, you cut it apart and you can't even see air gaps that used to be between the strands of wire.

This is a far better connection than solder can achieve, because the solder itself is a relatively poor electrical conductor, and has reliability issues from wicking.

This said... I've made many hundreds of excellent solder joints that have been excellent connections for many years with no signs of failing, and likely never will. However, if given the choice between a proper crimp and a solder connection, I will take the proper crimp any day. It also is very fast to do when you have a good crimper.

Soldering these large connectors takes a long time to cool. Crimping can speed the work up significantly.

Nice work "Alan" I crimp all of my connections also, useing the same crimper as Alan's pictured.

Crimping is much faster and 100% reliability so far. I mostly use aluminum butt connectors from electrical stores. The crimper I use is from http://www.westmountainradio.com and has three die sets that go with it.