Wire keeps coming out of crimp connectors.

[Sir Auros]

IIRC, mountain had an uber-neat wiring job in his cab. because he used to work with aviation wiring as a living. Or am I thinking of someone else?

[MaximRecoil]

Please tell me how properly twisting and crimping a connection removes that surface-to-surface connection? 

Say what? "Properly twisting and crimping a connection doesn't remove that surface-to-surface connection. That's the point. When you cut the wire and twist it back together the circuit is now being closed by surface-to-surface contact.

You do realize that for oxidation of the metal surface to occur the metal has to be exposed to an oxidizing material.  A properly twisted and crimped connection will have no oxidizers around to oxidize the copper.  The only way the copper will oxidize is if the person making the crimp did a very poor job of crimping the connection, and in that case it wouldn't matter if he twisted it together OR used your fold technique.

So you think that crimping a typical insulated QD terminal on wires that have been spliced together by twisting, creates an air-tight seal which prevents oxidation?

If you don't cut the wire, the only surface-to-surface contact you have to rely on is between the wire itself and the QD. As long as that QD is making solid contact with the wire at any point, the circuit will be properly closed. Even a less-than-perfect crimp which is say, only making solid contact with the wire on one side of it, will still work fine because there is no break in the wire. This amounts to a greater margin for error and is a good thing.

If you cut the wire and twist it back together, you now have to rely on surface-to-surface contact between the two ends of the cut wires themselves, and between the wires and the QD. A less-than-perfect crimp that only gets good contact on one side (usually because the other wire got pushed over and somewhat separated during the crimp), can cause problems later, even if not immediately apparent.

There is an inherent, undeniable redundancy with the "fold technique" as you call it, which means a greater margin for error.

But it boils does to this: Why cut wires that you don't have to? There are no advantages; only potential disadvantages.

[2600]

I had a couple PM's asking questions.  Here is a site that uses both tools and you can see the difference in the crimp.
http://www.kampenwagen.co.uk/Crimping.htm

Not sure of the brand, but here's one that looks like mine for under $20
http://www.partsexpress.com/pe/showdetl.cfm?Partnumber=360-642

[csa3d]

Wow.  I thought this thread was going to be a long-winded, fight about nothing again.. and turns out to be highly informational.

@2600:  Looking at that crimping example link, I really had no idea that you're supposed to put TWO crimps in those plastic ends, let alone the idea of there being an uber-crimper!  Great stuff!  That should go in the wiki for sure.

-csa

[Daniel B.]

I had no idea I was supposed to crimp 2 times on the connector. I've got some more work to do....

[AcidArmitage]

fvck all of you, elmers glue is the best. glob it in the QD and bam! 

[Chris2]

Everything shown in that package I essentially have. I've been using a crimper, red (16-22awg) crimps, and 18awg wire, and have been using the daisy-chain method with some success. However, I'm going to try that "single long wire" method and see how that goes.

Glad to see so many people are concerned with stuff like this. 

[Chris2]

One more note: anyone know a good place to get wire and crimps?

[TheShanMan]

Sometimes auto parts places have decent prices on wire and terminals. I'm headed over later today to get some from a regional shop that I know has good prices.

[DeLuSioNal29]

I crimp, but next time I'm doing a ground loop, I'm going to do it all with one piece of wire. Yeah, it might take more time, but it'd be worth it for the additional secureness of the wire as well as neatness.

The only downside I can see (both methods are good) is that if you crimp connectors all at once on a long wire, what if one of the connectors are too short to reach another microswitch?  I cut each one to length as I wired my CP, and even so, I ended up re-doing a few because I cut them too short.

~ DeLuSioNaL

[Ed_McCarron]

It probably won't make a difference, but it looks like he crimped the lugs with the wrong crimper.  Correct me if I'm wrong but I don't think you're supposed to use a cleat on an insulated connector.  It can damage the insulation.

Correct.  The crimp tool I use in the field has two nests; one for insulated, and one for non-insulated.  The insulated nest forms the crimp without breaking the insulation sleeve.

That said, we (electricians) all use the pinching nest - even on insulated connectors because it seems to work better if the insulation isn't critical.

The one I use in the shop has a ratchet setup and makes a formed crimp - looks much neater, but was bloody expensive.

Either way, a properly done crimp is gastight - oxidation internally won't be a problem.  The key is properly done.  Correct lug size, correct # of conductors, correct prep.  Theres still a good bit of wiggle room.

[MaximRecoil]

Correct.  The crimp tool I use in the field has two nests; one for insulated, and one for non-insulated.  The insulated nest forms the crimp without breaking the insulation sleeve.

That said, we (electricians) all use the pinching nest - even on insulated connectors because it seems to work better if the insulation isn't critical.

That's the type of crimp I use for insulated connectors as well, and I've done so ever since I noticed the installers at a car audio place using that type of crimp. It creates a much tighter crimp than the typical football-shaped crimps on the ends of cheap crimpers.  

The one I use in the shop has a ratchet setup and makes a formed crimp - looks much neater, but was bloody expensive.

I wonder if that's like the crimps that Level42 (I think?) makes. I've seen pictures but I don't know where to find them right now; but they look very professional.

[Ed_McCarron]

I wonder if that's like the crimps that Level42 (I think?) makes. I seen pictures but I don't know where to find them right now; but they look very professional.

Heres the one I have...

http://www.electriciansupplies.com/index.cfm/S/312/N/11537/P/83105/Thomas_&_Betts_WT145A_--_1_each.htm

[fixedpigs]

Oxidation occurs on the surface, which can degrade a surface-to-surface contact connection.

you know that electricity only travels on the surface of the wire right...and not through it...?

[Ed_McCarron]

Oxidation occurs on the surface, which can degrade a surface-to-surface contact connection.

you know that electricity only travels on the surface of the wire right...and not through it...?

Skin effect only applies to higher frequencies.  At DC, we use the whole wire, IIRC.

[MaximRecoil]

I wonder if that's like the crimps that Level42 (I think?) makes. I seen pictures but I don't know where to find them right now; but they look very professional.

Heres the one I have...

http://www.electriciansupplies.com/index.cfm/S/312/N/11537/P/83105/Thomas_&_Betts_WT145A_--_1_each.htm

You weren't kidding when you said they were expensive. I'd like to see what the crimps look like.

Do you have crimpers for large (e.g. 4 to 4/0 gauge) terminals? I have a cheap (less than $20) anvil-type setup that you use with a hammer. It actually works quite well. I wanted some handheld ones but they are ridiculously expensive. Here is what the crimp looks like done with the cheap device I have:





It is an incredibly secure crimp, but the device is not very convenient to use due to needing a solid surface to rest it on and swinging room for a hammer.

[MaximRecoil]

Oxidation occurs on the surface, which can degrade a surface-to-surface contact connection.

you know that electricity only travels on the surface of the wire right...and not through it...?

Skin effect only applies to higher frequencies.  At DC, we use the whole wire, IIRC.

That's true. The topic comes up in car audio forums a lot, usually in discussions about whether power wire (from the battery to the amplifier) with a high strand count is worth paying extra for or not. Some people cite "skin effect" as a reason that a higher number of fine strands (giving more surface area) is useful for power wire. That's not the case. In this context, solid core would flow just as well as stranded. However, the higher strand counts do add flexibility, which is useful for installation in vehicles.

[Ed_McCarron]

I wonder if that's like the crimps that Level42 (I think?) makes. I seen pictures but I don't know where to find them right now; but they look very professional.

Heres the one I have...

http://www.electriciansupplies.com/index.cfm/S/312/N/11537/P/83105/Thomas_&_Betts_WT145A_--_1_each.htm

You weren't kidding when you said they were expensive. I'd like to see what the crimps look like.

Do you have crimpers for large (e.g. 4 to 4/0 gauge) terminals? I have a cheap (less than $20) anvil-type setup that you use with a hammer. It actually works quite well. I wanted some handheld ones but they are ridiculously expensive. Here is what the crimp looks like done with the cheap device I have:





It is an incredibly secure crimp, but the device is not very convenient to use due to needing a solid surface to rest it on and swinging room for a hammer.

Nope.  Any wire larger than #4 gets a compression lug with a screw around here.  I had to sub out some 0000 jumpers that had crimp lugs.

[Ed_McCarron]

You weren't kidding when you said they were expensive. I'd like to see what the crimps look like.

Its some mil-spec.  Price goes way up.  No digicam here at the office with me, but I'll try to remember to take one home to take a pic of.  It makes the insulation sleeve square, with indents for the wire.  Looks slick.  Not sure if its worth the cash tho.  One customer demanded that particular tool, so they paid for it.

[saint]

  Stop making me clean up threads you bozos.

(No, I don't mean you. I mean the other bozos.)

(thread cleaned up and resurrected)

[MaximRecoil]

Nope.  Any wire larger than #4 gets a compression lug with a screw around here.  I had to sub out some 0000 jumpers that had crimp lugs.

The device I have will crimp up to 4/0 (0000) AWG lugs. It has markings on the side of the anvil to show how far to pound the the anvil down for each gauge, from 4 to 4/0. It is pretty heavily built. The body is made from 1/8" steel and the anvil is made from 3/4" square solid steel. If you had a lot of 4/0 lugs to crimp and/or you had to conform to a particular specification, you wouldn't want to use something like this though.

Its some mil-spec.  Price goes way up.  No digicam here at the office with me, but I'll try to remember to take one home to take a pic of.  It makes the insulation sleeve square, with indents for the wire.  Looks slick.  Not sure if its worth the cash tho.  One customer demanded that particular tool, so they paid for it.

That would be cool. The crimps I've seen in Level42's (still not sure if it was him or someone else) pictures of his wiring were square or rectangular like that I believe. They looked like some of the factory crimps I've seen here and there; for example, this factory crimp:



That one is rectangular for the crimp on the copper and has two indentations on either side for the insulation crimp.