The typical sub-D contacts that I'm familiar with use a different crimper
than described, Tim.

Typical contacts for commercial grade sub-D connectors are similar to Molex
contacts, but much smaller.. but they also have two sets of tabs that form U
shapes, one where the stripped wire gets crimped, and the second set for
gripping the wire's insulation.

The cross-section of the crimp area for the wire looks like the tabs rolled
in to form someting like a 3 with a radius at the opening of the 3.
The better quality crimpers will be compound-action types with ratcheting
mechanisms to insure a full cycle, and numerous brands are good ones.. AMP,
Black Box, Sargent, etc (all made in U.S.A.).

A simple scissor-type crimp tool will likely produce inconsistent crimps..
some may be OK, others may separate from the wire or be loosely crimped to
the wire strands.

The crimper you described is generally for (fully round) machined contacts
with heavier wall thicknesses, as used in high reliability avionics-type or
aircraft circular connectors, but also used in higher quality sub-D
connectors.
Those crimpers sorta resemble a Buchanan splice crimper with an extension
tube protruding from one side (Daniels tool, etc).
The higher quality contacts are much better quality that typical commercial
grade contacts which are stamped and formed from thin sheet brass.

You're definitely correct about not crushing the crimp areas with an
incorrect tool, as the widening of the contact will interfere with proper
installation, and the contacts are supposed to somewhat float in the
connector bodies, but have good alignment.

For myself, soldering pre-assembled connectors is quicker than crimping, and
a proper soldering job should be more reliable than crimping for someone
that doesn't have some crimping experience, and definitely more reliable
than trying to improvise a good crimp without the proper crimp tool.

--
WB
..........


"Tim Wescott" wrote in message
...
On 11/04/2010 04:44 PM, Karl Townsend wrote:
On Thu, 04 Nov 2010 12:19:48 -0700, Tim
wrote:

On 11/03/2010 06:51 PM, Karl Townsend wrote:
I need to make up connectors like you see on the back of a computer.
My servo amps have a couple 2 row 15 pin, a 2 row 25 pin, and a 3 row
26 pin places to connect.

I'm seeing a bewildering number of possibilities in digikey. FWIW the
connector plug I'm after is similar to this pictu
http://search.digikey.com/scripts/Dk...name=A32073-ND

or digikey part A32073-ND. I'm not after this part, just trying to
show the connector.

I'm not at all good at soldering in tight places. I much prefer
something that can be made up by crimping. I have a Molex type crimp
tool.

can someone suggest a good series of parts for this?

Crimpers for those things need to be high quality, and the decent ones
cost $$$.

I guess I'll find out. I plan to crimp them with whatever I can come
up with and then solder before inserting. Total cost was under $20 so
I'm not out much if it don't work. Plan "B" would be to hire the job
out and get the solder type.

The pins have a round barrel into which you insert the wire. The crimper
pushes four hardened pins into the barrel, dimpling it and pressing it
onto the wire. Tres fancy. Because the barrel of the pin extends down
into the hole in the housing you can't just crimp it by crushing it -- you
have to do something that'll make it grip the wire without deforming it to
the point where it won't go into its hole.

(I think the barrel is relieved where the crimper dimples it, so any
little 'outies' don't interfere with putting it into the housing).

How far out in the boonies are you? Any electronics place that deals with
DB connectors has a chance at having the crimper; if there's a contract
cable assembly guy near you he'd probably be happy to make them up.

Note: I'd solder them myself, but I solder all the time. If I had to hire
it done I'd either make damn sure the guy understood crimped DB
connections, or I'd hire a kid to do the soldering and I'd stand over him
for the first few connectors to make sure they were right. If I made more
than 10 cables a year I'd probably buy a crimper -- but I make less than
1, on average.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html