How does crimping work?
in [Repair]
|
From: Bob Larter on 3 Dec 2009 23:48 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. -- W . | ,. w , "Some people are alive only because \|/ \|/ it is illegal to kill them." Perna condita delenda est ---^----^---------------------------------------------------------------
From: Sylvia Else on 3 Dec 2009 22:59 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. Sylvia.
From: Dave Plowman (News) on 4 Dec 2009 05:23 In article <0076c844$0$16926$c3e8da3(a)news.astraweb.com>, Sylvia Else <sylvia(a)not.at.this.address> 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. The standard crimp tool for insulated terminals has parallel jaws, and those terminals have no provision for the metal part to crimp onto the insulation. Nor will the insulation fit inside the metal part if you're using the correct size, or at least with most cables. A very thin wall type might. But the design calls for all the metal part of the crimp to be in contact with the conductor. -- *Sticks and stones may break my bones but whips and chains excite me* Dave Plowman dave(a)davenoise.co.uk London SW To e-mail, change noise into sound.
From: Sylvia Else on 4 Dec 2009 06:10 Dave Plowman (News) wrote: > In article <0076c844$0$16926$c3e8da3(a)news.astraweb.com>, > Sylvia Else <sylvia(a)not.at.this.address> 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. > > The standard crimp tool for insulated terminals has parallel jaws, and > those terminals have no provision for the metal part to crimp onto the > insulation. Nor will the insulation fit inside the metal part if you're > using the correct size, or at least with most cables. A very thin wall > type might. But the design calls for all the metal part of the crimp to be > in contact with the conductor. > 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. Sylvia.
From: F Murtz on 4 Dec 2009 06:12
Dave Plowman (News) wrote: > In article<0076c844$0$16926$c3e8da3(a)news.astraweb.com>, > Sylvia Else<sylvia(a)not.at.this.address> 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. > > The standard crimp tool for insulated terminals has parallel jaws, and > those terminals have no provision for the metal part to crimp onto the > insulation. Nor will the insulation fit inside the metal part if you're > using the correct size, or at least with most cables. A very thin wall > type might. But the design calls for all the metal part of the crimp to be > in contact with the conductor. > The proper crimp tool for the small insulated lugs as far as I know has two crimping sections separated by a gap which is designed to crimp both the conducting section on to the cable and the plastic on the lug to the cable insulation at the same time.The cheaper tool which is more common does one operation at a time (once for the cable crimp and once for the insulation)I think that sylvia's lugs have a heavier section for copper to copper and a flimsy copper skirt which continues back inside the plastic insulation over the cable insulation but I may be wrong. |