How does crimping work?
in [Repair]
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From: Dave Plowman (News) on 4 Dec 2009 06:15 In article <0094bf1a$0$26897$c3e8da3(a)news.astraweb.com>, Sylvia Else <sylvia(a)not.at.this.address> wrote: > In the example I posted earlier > http://members.optusnet.com.au/sylviae/crimp.jpg > note how the lug on the left has a different diameter where it's crimped > around the insulation to where it's crimped around the conductor. That > difference existed prior to crimping - the diameter of the hole for the > wire changes part of the way down the shaft so that insulation cannot go > any further. > It's true that this difference is not obviously reflected in the tool I > used, but given that plastic deforms much more easily than metal, I can > believe that having jaws the same size works out OK (it certainly seems > to), and has the advantage that there's no right-way around to insert > the lug into the tool. IMHO, that type of crimp would require a special tool - not the generic type for these pre-insulated connectors. -- *Arkansas State Motto: Don't Ask, Don't Tell, Don't Laugh. Dave Plowman dave(a)davenoise.co.uk London SW To e-mail, change noise into sound.
From: Sylvia Else on 4 Dec 2009 18:49 Dave Plowman (News) wrote: > In article <0094bf1a$0$26897$c3e8da3(a)news.astraweb.com>, > Sylvia Else <sylvia(a)not.at.this.address> wrote: >> In the example I posted earlier > >> http://members.optusnet.com.au/sylviae/crimp.jpg > >> note how the lug on the left has a different diameter where it's crimped >> around the insulation to where it's crimped around the conductor. That >> difference existed prior to crimping - the diameter of the hole for the >> wire changes part of the way down the shaft so that insulation cannot go >> any further. > >> It's true that this difference is not obviously reflected in the tool I >> used, but given that plastic deforms much more easily than metal, I can >> believe that having jaws the same size works out OK (it certainly seems >> to), and has the advantage that there's no right-way around to insert >> the lug into the tool. > > IMHO, that type of crimp would require a special tool - not the generic > type for these pre-insulated connectors. > The tool I have works much better on that type of connector than it does on the type where the lug metal doesn't extend back over the cable insulator. In the latter case, it merely squeezes some plastic which then returns to more or less its original shape. The tool may really be intended for lugs that crimp a longer section of the conductor, but I haven't come across any such lugs. Sylvia.
From: Ross Herbert on 5 Dec 2009 20:09 On Tue, 01 Dec 2009 00:46:08 +0000 (GMT), "Dave Plowman (News)" <dave(a)davenoise.co.uk> wrote: :In article <7nj3mqF3m9jbuU1(a)mid.individual.net>, : Trevor Wilson <trevor(a)SPAMBLOCKrageaudio.com.au> wrote: :> > Depends on the use. I'd say the most common crimp terminals are in :> > some form of spring loaded contact. : :> **We're discussing CRIMP terminals. Like this: : :> http://www.ami.ac.uk/courses/topics/0119_crmp/index.html : :> Copper is the material, not brass. : :Heavy duty electrical ones may be - but the most common ones like in :computers and cars are brass. Aha! Now you have finally made the distinction in your argument... Commonly used terminals in the whitegoods and automotive areas (ie. QC crimp terminals) are indeed made of brass. But that is about the limit of use for this material. When it comes to electrical crimp lugs, spade terminals etc, then the lug/terminal material is always copper, unless you are using aluminium conductors where the terminal material will be aluminium. Take a look at the Utilux catalogue (small insulated and un-insulated terminals) http://www.utilux.com.au/pdf/4.pdf and you will see mentioned at the top of several pages the material is electro-tinned copper. Only the QC tabs are brass.
From: Dave Plowman (News) on 6 Dec 2009 05:10 In article <kg0mh5d3rvkij3o71ogh0lgdipcdlv8ves(a)4ax.com>, Ross Herbert <rherber1(a)bigpond.net.au> wrote: > Aha! Now you have finally made the distinction in your argument... Made it pretty well from the start. As I got the impression the OP wasn't talking about heavy duty power connections. > Commonly used terminals in the whitegoods and automotive areas (ie. QC > crimp terminals) are indeed made of brass. But that is about the limit > of use for this material. When it comes to electrical crimp lugs, spade > terminals etc, then the lug/terminal material is always copper, unless > you are using aluminium conductors where the terminal material will be > aluminium. Almost anywhere you go, there will be more crimped terminals which aren't copper - as they are sprung as part of a plug and socket arrangement. Many inside your computer, for a start. TV as well. Etc. -- *If you ate pasta and anti-pasta, would you still be hungry? Dave Plowman dave(a)davenoise.co.uk London SW To e-mail, change noise into sound.
From: Bob Larter on 9 Dec 2009 07:52
Sylvia Else wrote: > Bob Larter wrote: >> Dave Plowman (News) wrote: >>> In article <00879530$0$8181$c3e8da3(a)news.astraweb.com>, >>> Sylvia Else <sylvia(a)not.at.this.address> wrote: >>>> Crimping the plastic is a waste of time anyway. On the failed lugs >>>> that I crimped, the plastic that covers the insulation has returned >>>> almost to its original shape, even though the tool squashes it >>>> pretty much flat. >>> >>> Something wrong there. The plastic acts as the cord clamp. >> >> Exactly. It's there for strain relief. >> > > In the example I posted earlier, which has strain relief, it's metal > that's crimped onto the insulator, not plastic. So? It still relieves strain on the metal-to-metal joint. -- W . | ,. w , "Some people are alive only because \|/ \|/ it is illegal to kill them." Perna condita delenda est ---^----^--------------------------------------------------------------- |