How does crimping work?
in [Repair]
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From: Sylvia Else on 30 Nov 2009 07:54 The obvious answer is that you bend the metal of the connector so that it holds the wire in place. This doesn't seem very satisfactory. Metal always retains some flexibility, even when bent beyond its yield point. No matter how hard you squeeze, there'll be some rebound when you release the pressure, which should result in a loose joint. After having had a bad experience trying to crip a lug some years ago, I recently faced the need to do this again. So I bought a moderately expensive ratchet based crimping tool. And, rather to my surprise, it actually works. But that doesn't answer the question of how. Sylvia.
From: F Murtz on 30 Nov 2009 08:01 Sylvia Else wrote: > The obvious answer is that you bend the metal of the connector so that > it holds the wire in place. > > This doesn't seem very satisfactory. Metal always retains some > flexibility, even when bent beyond its yield point. No matter how hard > you squeeze, there'll be some rebound when you release the pressure, > which should result in a loose joint. > > After having had a bad experience trying to crip a lug some years ago, I > recently faced the need to do this again. So I bought a moderately > expensive ratchet based crimping tool. And, rather to my surprise, it > actually works. > > But that doesn't answer the question of how. > > Sylvia. Usually the conductor is the same metal as the lug, it will have the same memory so if it is all squished it should stay there.Expanding and contracting in use at the same rate. (maybe)
From: Rich Webb on 30 Nov 2009 08:23 On Mon, 30 Nov 2009 23:54:12 +1100, Sylvia Else <sylvia(a)not.at.this.address> wrote: >The obvious answer is that you bend the metal of the connector so that >it holds the wire in place. > >This doesn't seem very satisfactory. Metal always retains some >flexibility, even when bent beyond its yield point. No matter how hard >you squeeze, there'll be some rebound when you release the pressure, >which should result in a loose joint. > >After having had a bad experience trying to crip a lug some years ago, I >recently faced the need to do this again. So I bought a moderately >expensive ratchet based crimping tool. And, rather to my surprise, it >actually works. > >But that doesn't answer the question of how. Because the wire bundle inside the crimp also rebounds? Interesting NASA paper that may shed some light: <http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20080013394_2008012901.pdf> -- Rich Webb Norfolk, VA
From: Fred Bartoli on 30 Nov 2009 09:09 Rich Webb a �crit : > On Mon, 30 Nov 2009 23:54:12 +1100, Sylvia Else > <sylvia(a)not.at.this.address> wrote: > >> The obvious answer is that you bend the metal of the connector so that >> it holds the wire in place. >> >> This doesn't seem very satisfactory. Metal always retains some >> flexibility, even when bent beyond its yield point. No matter how hard >> you squeeze, there'll be some rebound when you release the pressure, >> which should result in a loose joint. >> >> After having had a bad experience trying to crip a lug some years ago, I >> recently faced the need to do this again. So I bought a moderately >> expensive ratchet based crimping tool. And, rather to my surprise, it >> actually works. >> >> But that doesn't answer the question of how. > > Because the wire bundle inside the crimp also rebounds? > > Interesting NASA paper that may shed some light: > <http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20080013394_2008012901.pdf> > Interesting. And the FEM simulation vs measurement paragraph is somewhat impressive. -- Thanks, Fred.
From: Dave Plowman (News) on 30 Nov 2009 10:09
In article <4b13c243$1(a)dnews.tpgi.com.au>, F Murtz <haggisz(a)hotmail.com> wrote: > Usually the conductor is the same metal as the lug, it will have the > same memory so if it is all squished it should stay there.Expanding and > contracting in use at the same rate. (maybe) Most connectors are brass - to give more strength. Cable usually copper. -- *Why are a wise man and a wise guy opposites? Dave Plowman dave(a)davenoise.co.uk London SW To e-mail, change noise into sound. |