How does crimping work?

S

Sylvia Else

Guest
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.
 
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
Click to expand...
same memory so if it is all squished it should stay there.Expanding and
contracting in use at the same rate. (maybe)
 
On Mon, 30 Nov 2009 23:54:12 +1100, Sylvia Else
<sylvia@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.
Click to expand...
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
 
Rich Webb a écrit :
On Mon, 30 Nov 2009 23:54:12 +1100, Sylvia Else
sylvia@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
Click to expand...
Interesting.
And the FEM simulation vs measurement paragraph is somewhat impressive.


--
Thanks,
Fred.
 
In article <4b13c243$1@dnews.tpgi.com.au>,
F Murtz <haggisz@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)
Click to expand...
Most connectors are brass - to give more strength. Cable usually copper.

--
*Why are a wise man and a wise guy opposites?

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.
 
In article <00b33d3e$0$12335$c3e8da3@news.astraweb.com>,
Sylvia Else <sylvia@not.at.this.address> wrote:
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.
Click to expand...
Having the correct crimp tool is essential for good results.

--


Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.
 
Dave Plowman (News) wrote:
In article<4b13c243$1@dnews.tpgi.com.au>,
F Murtz<haggisz@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.

crimp lugs are usually copper for copper wire
Click to expand...
 
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.
The crimp wire squishes the corners of the pin so intensely,
Click to expand...
that a gas-tight connection forms, 4 for each winding.
That makes a very reliable connection.
But only if you do the wrap correctly.
 
On Mon, 30 Nov 2009 17:56:29 +0000 (GMT), "Dave Plowman (News)"
<dave@davenoise.co.uk> wrote:

In article <4b13f3e6$1@dnews.tpgi.com.au>,
F Murtz <haggisz@hotmail.com> wrote:
Dave Plowman (News) wrote:
In article<4b13c243$1@dnews.tpgi.com.au>,
F Murtz<haggisz@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.

crimp lugs are usually copper for copper wire

Perhaps lug means some special terminal in the US?

But most of the crimped terminals you come across - like say in a car or
computer - are brass, but sometimes plated.
Click to expand...
Cite a reference.
 
In article <4b13f3e6$1@dnews.tpgi.com.au>,
F Murtz <haggisz@hotmail.com> wrote:
Dave Plowman (News) wrote:
In article<4b13c243$1@dnews.tpgi.com.au>,
F Murtz<haggisz@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.

crimp lugs are usually copper for copper wire
Click to expand...
Perhaps lug means some special terminal in the US?

But most of the crimped terminals you come across - like say in a car or
computer - are brass, but sometimes plated.

--
*If you're not part of the solution, you're part of the precipitate *

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.
 
In article <fh38h5931qpafh0rdpom1qpa9n3bn2epvp@4ax.com>,
PeterD <peter2@hipson.net> wrote:
But most of the crimped terminals you come across - like say in a car or
computer - are brass, but sometimes plated.

Cite a reference.
Click to expand...
Try cutting one open.

--
*How do you tell when you run out of invisible ink? *

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.
 
"Dave Plowman (News)" <dave@davenoise.co.uk> wrote in message
news:50c25cfc1fdave@davenoise.co.uk...
In article <4b13c243$1@dnews.tpgi.com.au>,
F Murtz <haggisz@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.
Click to expand...
**Only cheap, crappy crimps are brass. For copper wire, crimps should be
copper.


--
Trevor Wilson
www.rageaudio.com.au
 
"Sylvia Else" <sylvia@not.at.this.address> wrote in message
news:00b33d3e$0$12335$c3e8da3@news.astraweb.com...
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.
Click to expand...
**A properly sized crimp (to the wire size), used with a quality crimp tool,
used correctly, will ensure an excellent, gas tight connection. Better, in
fact, than a soldered joint.


--
Trevor Wilson
www.rageaudio.com.au
 
Dave Plowman (News) wrote:
In article <7nili3F3mc6v2U1@mid.individual.net>,
Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au> wrote:
Most connectors are brass - to give more strength. Cable usually
copper.

**Only cheap, crappy crimps are brass. For copper wire, crimps
should be copper.

Depends on the use. I'd say the most common crimp terminals are in
some form of spring loaded contact.
Click to expand...
**We're discussing CRIMP terminals. Like this:

http://www.ami.ac.uk/courses/topics/0119_crmp/index.html

Copper is the material, not brass.


--
Trevor Wilson
www.rageaudio.com.au
 
On Mon, 30 Nov 2009 18:28:28 +0000 (GMT), "Dave Plowman (News)"
<dave@davenoise.co.uk> wrote:

In article <fh38h5931qpafh0rdpom1qpa9n3bn2epvp@4ax.com>,
PeterD <peter2@hipson.net> wrote:
But most of the crimped terminals you come across - like say in a car or
computer - are brass, but sometimes plated.

Cite a reference.

Try cutting one open.
Click to expand...
That tells you nothing about the metal... Again, cite a reference.
 
In article <7nili3F3mc6v2U1@mid.individual.net>,
Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au> wrote:
Most connectors are brass - to give more strength. Cable usually
copper.

**Only cheap, crappy crimps are brass. For copper wire, crimps should be
copper.
Click to expand...
Depends on the use. I'd say the most common crimp terminals are in some
form of spring loaded contact. And those tend to be made of brass because
it is stronger than copper, so gives a better contact.

--
*How do you tell when you run out of invisible ink? *

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.
 
Rich Webb wrote:
On Mon, 30 Nov 2009 23:54:12 +1100, Sylvia Else
sylvia@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?
Click to expand...
It probably does, but the wide bundle is being subject to compression,
whereas the connector is subject to both compression and bending. I'd
expect a certain degree of unbending when the compression is released.

Sylvia.
 
Sjouke Burry wrote:
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.
The crimp wire squishes the corners of the pin so intensely,
that a gas-tight connection forms, 4 for each winding.
Click to expand...
I think you're referring to wire wrapping, which is something else.

Sylvia.
 
On Nov 30, 3:26 pm, "Dave Plowman (News)" <d...@davenoise.co.uk>
wrote:
In article <7nili3F3mc6v...@mid.individual.net>,
   Trevor Wilson <tre...@SPAMBLOCKrageaudio.com.au> wrote:

Most connectors are brass - to give more strength. Cable usually
copper.

**Only cheap, crappy crimps are brass. For copper wire, crimps should be
copper.

Depends on the use. I'd say the most common crimp terminals are in some
form of spring loaded contact. And those tend to be made of brass
Click to expand...
Phosphor bronze or beryllium copper are the springy metals in common
use (it may LOOK like brass...). A well-made crimp requires lots of
thought about materials. Commonly, copper stranded cable works, a
copper stranded
cable with a couple of SS strands works, a copper solid cable of the
same gage doesn't work... and don't even TRY to crimp to a SS
cable with 'electronic' tools and lugs.

Even the professionals get it wrong sometimes (Al wire is just fine
with
the right electrode paste and crimp lugs, but has a bad reputation).
When amateurs get 'kits' and pliers at the dollar store, the result
isn't
pretty.
 
In article <7nj3mqF3m9jbuU1@mid.individual.net>,
Trevor Wilson <trevor@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.
Click to expand...
Heavy duty electrical ones may be - but the most common ones like in
computers and cars are brass.

--
*He who laughs last, thinks slowest.

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.
 
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