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Bob Marshall

Joined: 23 Dec 2010
Posts: 3

Posted: Wed Feb 02, 2011 6:58 am Post subject: wire squash connections

I plan to use p-mags and the installation instructions show the connections made to the controller are simply striped wire leads placed under screws.  Since this is under the cowl, I was hoping that there was a better way.  Is there a crimped terminal that could be used along with some heat shrink tubing? 

My first post here though I have been reading for a while.  Thanks,

Bob

I would post a photo but I cannot figure how to do it.

_________________
RV-6A construction resumed. Planning electrical and building wing.

rlborger(at)mac.com
Guest

Posted: Wed Feb 02, 2011 7:42 am Post subject: wire squash connections

Bob,



Interesting.  I plan to put a pair of P-Mags on the Lycoming for my Toot.  



Rather than bare wires under a screw, I'd think about crimping a suitably sized  ring terminal onto the wire with proper shrink tube and placing the ring under the screw along with a lock washer.



Others, please chime in if there's an error in my thinking as it's info I'll eventually need.



Thanks,

Bob Borger

Europa Kit #A221 N914XL, XS Tri-Gear, Intercooled 914, Airmaster C/S Prop

http://www.europaowners.org/forums/gallery2.php?g2_itemId=60232

http://www.biplaneforumgallery.com/index.php?cat=10046

Europa Flying!

3705 Lynchburg Dr.

Corinth, TX  76208

Home:  940-497-2123

Cel:  817-992-1117

On Feb 2, 2011, at 8:58, Bob Marshall wrote:



 	  Quote: 	
		   

 

 I plan to use p-mags and the installation instructions show the connections made to the controller are simply striped wire leads placed under screws.  Since this is under the cowl, I was hoping that there was a better way.  Is there a crimped terminal that could be used along with some heat shrink tubing? 

 My first post here though I have been reading for a while.  Thanks,

 Bob

 I would post a photo but I cannot figure how to do it.

 

 --------

 RV-6A construction resumed.  Planning electrical and building wing.

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=329292#329292

nuckolls.bob(at)aeroelect
Guest

Posted: Wed Feb 02, 2011 2:26 pm Post subject: wire squash connections

At 09:58 AM 2/2/2011, you wrote:

 	  Quote: 	
		  

<marshall6916(at)sbcglobal.net>



I plan to use p-mags and the installation instructions show the 

connections made to the controller are simply striped wire leads 

placed under screws.  Since this is under the cowl, I was hoping 

that there was a better way.  Is there a crimped terminal that could 

be used along with some heat shrink tubing?


	


    Yeah, my biggest disappointment with that product.

    Their service experience with that configuration must

    be okay . . . that's what they've used since day one.

    Crimping the appendage of some sort of terminal in

    those connections might be a bit better than just

    crimping the wire . . . but not much.



    My best suggestion is to strip leads (20AWG)

    to proper length and then 'comb' them such

    that they all lay parallel to each other. Then

    connect with as much torque on the screws as

    you dare.



    Try to support the bundles within a few inches

    of where they connect with the ignition modules.

   Bob . . .

raymondj(at)frontiernet.n
Guest

Posted: Wed Feb 02, 2011 3:37 pm Post subject: wire squash connections

do not archive



General question on wires under screws.  Is there any benefit in using 

an antioxidant similar to what is used on Al wire in electrical panels. 

Perhaps not best but better than without?



Raymond Julian

Kettle River, MN



On 02/02/2011 03:22 PM, Robert L. Nuckolls, III wrote:

 	  Quote: 	
		   

 <nuckolls.bob(at)aeroelectric.com>



 At 09:58 AM 2/2/2011, you wrote:

> 

> <marshall6916(at)sbcglobal.net>

>

> I plan to use p-mags and the installation instructions show the

> connections made to the controller are simply striped wire leads

> placed under screws. Since this is under the cowl, I was hoping that

> there was a better way. Is there a crimped terminal that could be used

> along with some heat shrink tubing?



 Yeah, my biggest disappointment with that product.

 Their service experience with that configuration must

 be okay . . . that's what they've used since day one.

 Crimping the appendage of some sort of terminal in

 those connections might be a bit better than just

 crimping the wire . . . but not much.



 My best suggestion is to strip leads (20AWG)

 to proper length and then 'comb' them such

 that they all lay parallel to each other. Then

 connect with as much torque on the screws as

 you dare.



 Try to support the bundles within a few inches

 of where they connect with the ignition modules.

 Bob . . .

nuckolls.bob(at)aeroelect
Guest

Posted: Wed Feb 02, 2011 5:12 pm Post subject: wire squash connections

At 10:26 AM 2/2/2011, you wrote:

  	  Quote: 	
		  --> AeroElectric-List message posted by: Robert Borger <rlborger(at)mac.com>



 Bob,



 Interesting.  I plan to put a pair of P-Mags on the Lycoming for my Toot.  



 Rather than bare wires under a screw, I'd think about crimping a suitably sized  ring terminal onto the wire with proper shrink tube and placing the ring under the screw along with a lock washer.



 Others, please chime in if there's an error in my thinking as it's info I'll eventually need. 	


   Just so we're all on the same page . . .



   The twist-n-squash terminal strips featured in this

   thread are probably the best there is for taking

   wires to etched circuit boards with convenience,

   minimum cost and reliability . . . UNDER CERTAIN

   CONDITIONS. Here's one example of the technology:



 [img]cid:.0[/img]



   Here's one of my favorite $100 data acquisition modules that

   uses the same terminal strip. 



 [img]cid:.1[/img]

  

    Note that the bared end of a wire is NOT captured by

    a head of the mash-screw . . .



 [img]cid:.2[/img]



    But by the END of the mash-screw. Further, there is a buffer

    strip between the wire strands and the end of the screw. If one

    REALLY needs to use a twist-n-squash technology, this is one of

    the best.



    Legacy design goals for aviation (and other disciplines)

    have adopted processes that offer gas-tightness in the

    metallic joints of the current carrying pathway along

    with wire support immediately adjacent to the gas-tight

    joint that prevents failure of the wire under vibration.



    Without getting in too much of a dither about new design

    goals, I think the best application of this process calls

    for parallel strands of wire pressed into the lower

    concave surface of the cavity with force from above

    offered by the screw. Then supply bundle support within

    a couple inches of the squash-joints.



    Note that is NOT what I did on this particular example . . .

    but then this DAM isn't expected to be in place and

    functioning after what we hope is decades of otherwise

    unattended service.



 

   Bob . . .

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rlborger(at)mac.com
Guest

Posted: Wed Feb 02, 2011 5:44 pm Post subject: wire squash connections

Bob,



Oh, OK.  Now I see (literally) what was being talked about.

Not the "wrap the wire around the screw and tighten" kind of under screw.

Would crimping a D-Sub female connector pin onto the end of the wire and adding a couple layers of shrink tube over the junction for some stress relief provide a better item to be pressed under the screw?  Again assuming you would provide some wire support close to the box.

Thanks,

 Bob



 

 

On Feb 2, 2011, at 17:25, Robert L. Nuckolls, III wrote:

 	  Quote: 	
		   At 10:26 AM 2/2/2011, you wrote:

  	  Quote: 	
		  --> AeroElectric-List message posted by: Robert Borger <rlborger(at)mac.com (rlborger(at)mac.com)>



 Bob,



 Interesting.  I plan to put a pair of P-Mags on the Lycoming for my Toot.  



 Rather than bare wires under a screw, I'd think about crimping a suitably sized  ring terminal onto the wire with proper shrink tube and placing the ring under the screw along with a lock washer.



 Others, please chime in if there's an error in my thinking as it's info I'll eventually need. 	


   Just so we're all on the same page . . .



   The twist-n-squash terminal strips featured in this

   thread are probably the best there is for taking

   wires to etched circuit boards with convenience,

   minimum cost and reliability . . . UNDER CERTAIN

   CONDITIONS. Here's one example of the technology:



 <1e81a25b.jpg>



   Here's one of my favorite $100 data acquisition modules that

   uses the same terminal strip. 



 <1e81a2d8.jpg>

  

    Note that the bared end of a wire is NOT captured by

    a head of the mash-screw . . .



 <1e81a345.jpg>



    But by the END of the mash-screw. Further, there is a buffer

    strip between the wire strands and the end of the screw. If one

    REALLY needs to use a twist-n-squash technology, this is one of

    the best.



    Legacy design goals for aviation (and other disciplines)

    have adopted processes that offer gas-tightness in the

    metallic joints of the current carrying pathway along

    with wire support immediately adjacent to the gas-tight

    joint that prevents failure of the wire under vibration.



    Without getting in too much of a dither about new design

    goals, I think the best application of this process calls

    for parallel strands of wire pressed into the lower

    concave surface of the cavity with force from above

    offered by the screw. Then supply bundle support within

    a couple inches of the squash-joints.



    Note that is NOT what I did on this particular example . . .

    but then this DAM isn't expected to be in place and

    functioning after what we hope is decades of otherwise

    unattended service.



 

   Bob . . .

nuckolls.bob(at)aeroelect
Guest

Posted: Wed Feb 02, 2011 6:24 pm Post subject: wire squash connections

 	  Quote: 	
		  

Would crimping a D-Sub female connector pin onto the end of the wire 

and adding a couple layers of shrink tube over the junction for some 

stress relief provide a better item to be pressed under the 

screw?  Again assuming you would provide some wire support close to the box.


	


     That might 'protect' the wire but now you

     have a single, solid, small diameter being

     captured between two surfaces having a larger

     radius. I.e., potentially less contact surface

     area than one could get with a compressed

     stack of wire strands (19 of them when it

     comes to legacy standard wire).



     The guys who designed this terminal strip

     were no dummies. It's really a pretty well

     thought out product. But I'd bet that they

     would not recommend that it be used under

     the cowl on any vehicle. Not recommending

     doesn't make it automatically "bad" . . .

     just not the best we know how to do. I

     think the risks are low.



     One could use PIDG 'pins' . . .



http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=165168-ND



   Bob . . .

nuckolls.bob(at)aeroelect
Guest

Posted: Wed Feb 02, 2011 6:27 pm Post subject: wire squash connections

At 06:12 PM 2/2/2011, you wrote:

 	  Quote: 	
		  



do not archive



General question on wires under screws.  Is there any benefit in 

using an antioxidant similar to what is used on Al wire in 

electrical panels. Perhaps not best but better than without?


	


     Probably wouldn't hurt . . . but unless

     we're talking about a really bad(at)#$(at)

     environment (salt air on sea-going boat?)

     I can't imagine that it would help.

   Bob . . .

dsvs(at)ca.rr.com
Guest

Posted: Wed Feb 02, 2011 7:56 pm Post subject: wire squash connections

Or you could use ferrules.  When they are crimper down the contact is flat.

See

http://www.alliedelec.com/search/searchresults.aspx?N=0&Ntk=Primary&Ntt=ferr

els



--

dsvs(at)ca.rr.com
Guest

Posted: Wed Feb 02, 2011 8:09 pm Post subject: wire squash connections

You will need to reattach the "els" to the link on the allied web site



--

rlborger(at)mac.com
Guest

Posted: Wed Feb 02, 2011 8:26 pm Post subject: wire squash connections

Bob,



Yes, I can see the PIGD pin working.  



If contact area is the issue, how about crimp on male spade?  Lots of contact area for the screw to mash into.  It has a crimp onto the wire and a crimp onto the insulation.  Add some heat shrink tubing for strain relief and support the wire.



Bob



On Feb 2, 2011, at 7:20 PM, Robert L. Nuckolls, III wrote:



 	  Quote: 	
		   

 

 

> 

> Would crimping a D-Sub female connector pin onto the end of the wire and adding a couple layers of shrink tube over the junction for some stress relief provide a better item to be pressed under the screw?  Again assuming you would provide some wire support close to the box.

 

    That might 'protect' the wire but now you

    have a single, solid, small diameter being

    captured between two surfaces having a larger

    radius. I.e., potentially less contact surface

    area than one could get with a compressed

    stack of wire strands (19 of them when it

    comes to legacy standard wire).

 

    The guys who designed this terminal strip

    were no dummies. It's really a pretty well

    thought out product. But I'd bet that they

    would not recommend that it be used under

    the cowl on any vehicle. Not recommending

    doesn't make it automatically "bad" . . .

    just not the best we know how to do. I

    think the risks are low.

 

    One could use PIDG 'pins' . . .

 

 http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=165168-ND

 

 

 

  Bob . . .

nuckolls.bob(at)aeroelect
Guest

Posted: Wed Feb 02, 2011 9:27 pm Post subject: wire squash connections

At 11:22 PM 2/2/2011, you wrote:

 	  Quote: 	
		  



Bob,



Yes, I can see the PIGD pin working.



If contact area is the issue, how about crimp on male spade?  Lots 

of contact area for the screw to mash into.  It has a crimp onto the 

wire and a crimp onto the insulation.  Add some heat shrink tubing 

for strain relief and support the wire.


	


    I like the pins better . . . or simply

    the combed strands.

   Bob . . .

Bob Marshall

Joined: 23 Dec 2010
Posts: 3

Posted: Wed Feb 02, 2011 9:31 pm Post subject: Re: wire squash connections

Great suggestions, thanks everyone!!  I think I will order the ferrules from Allied though they come in packs of 100.  If I do order, does anyone want a few?

My thinking is that the ferrules will do as advertised and prevent strand breaks and maybe a bit of oxidation, too.  Just seems like a better connection.

edit: 

I just read that the ferrules take a special crimper.  oh well, back to the drawing board.

_________________
RV-6A construction resumed. Planning electrical and building wing.

mikerv6a(at)ao-cs.com
Guest

Posted: Wed Feb 02, 2011 9:46 pm Post subject: wire squash connections

Wire termination ferrules are designed for use in

connectors of the type used in P-Mags.

See digikey.com, part number 298-10044-ND for an example.



These ferrules are tin-plated copper, and they provide

an insulated segment that keeps the wire bend away from

the stripped part of the wire- this helps to prevent

flexing that can break individual wire strands.



The ferrule crimper (yes, another tool...) leaves

flat sides on the ferrule that align with the

clamp action of the terminal into which the ferrule

is inserted.



Ferrules are sized for various wire gauges, the part

number that I gave above is for #18. Ferrules are

available to receive two conductors, having a double-

width insulation sleeve. Catalogs often contain part

numbers that offer various ferrule tube lengths, but

the small connectors that are used on P-Mags would

probably lead to trimming the longer ferrules to fit,

which is OK.



I think that this approach is more desirable than the

PIDG pins, because the ferrule can be trimmed  to length

so that the ferrule fits quite neatly into the receiving

area of the connector body, leaving the ferrule's insulator

supported within the box-shaped entry to the connector.

PIDG pins have enough bulk that, in some of these kinds

of connectors, the pin projects outside the confines of

the connector body: This means that the pin is essentially

a miniature cantilevered beam carrying whatever bending

load that might exist in the wire's installation. In the

long run this might result in flexing and breakage of

the PIDG pin.



Mike Linse

Corvallis, OR





 	  Quote: 	
		   



 Bob,



 Yes, I can see the PIGD pin working.



 If contact area is the issue, how about crimp on male spade?  Lots of

 contact area for the screw to mash into.  It has a crimp onto the wire and

 a crimp onto the insulation.  Add some heat shrink tubing for strain

 relief and support the wire.



 Bob



 On Feb 2, 2011, at 7:20 PM, Robert L. Nuckolls, III wrote:



> 

> <nuckolls.bob(at)aeroelectric.com>

>>

>> Would crimping a D-Sub female connector pin onto the end of the wire

>> and adding a couple layers of shrink tube over the junction for some

>> stress relief provide a better item to be pressed under the screw?

>> Again assuming you would provide some wire support close to the box.

>

>    That might 'protect' the wire but now you

>    have a single, solid, small diameter being

>    captured between two surfaces having a larger

>    radius. I.e., potentially less contact surface

>    area than one could get with a compressed

>    stack of wire strands (19 of them when it

>    comes to legacy standard wire).

>

>    The guys who designed this terminal strip

>    were no dummies. It's really a pretty well

>    thought out product. But I'd bet that they

>    would not recommend that it be used under

>    the cowl on any vehicle. Not recommending

>    doesn't make it automatically "bad" . . .

>    just not the best we know how to do. I

>    think the risks are low.

>

>    One could use PIDG 'pins' . . .

>

> http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=165168-ND

>

>  Bob . . .

dsvs(at)ca.rr.com
Guest

Posted: Wed Feb 02, 2011 9:56 pm Post subject: wire squash connections

Bob I use them on my P-MAGS. Like Bob N says these will not form gas tight

connections in screw down devices, but they do provide a fairly lagre

contact area and they keep the wire from being stressed.  I check mine every

condition inspection. So far I have not needed to replace any wires but it

will be easy when the time comes.  I wish that the P_MAGS came with D-SUB

connectors, but I am not holding my breath.  Don 



--

bbradburry(at)bellsouth.n
Guest

Posted: Thu Feb 03, 2011 3:19 am Post subject: wire squash connections

If it is an experimental plane, put some on if you want.



Bill B



--

mrspudandcompany(at)veriz
Guest

Posted: Thu Feb 03, 2011 6:50 am Post subject: wire squash connections

 	  Quote: 	
		  >If contact area is the issue, how about crimp on male spade?  Lots of 

>contact area for the screw to mash into.  It has a crimp onto the wire and 

>a crimp onto the insulation.  Add some heat shrink tubing for strain 

>relief and support the wire.



    I like the pins better . . . or simply

    the combed strands.

   Bob . . .


	


        Where I used to work we used a similar terminal in one of our 

devices.  We used a crimp on pin on the end of the wires before insertion. 

This made for a nice looking finished job, But unless the assembly tech 

really torqued the screws down very tight, they would tend to loosen.



Roger

ainut(at)knology.net
Guest

Posted: Thu Feb 03, 2011 8:53 am Post subject: wire squash connections

Bob, can you tell if the Labjack U12, www.labjack.com/U12 , is 

suitable?  I had no idea that termination was such a concern.  I've had 

the U12 for several years and hope to use it in my Mustang II 

(Mustang2.)  It was only $100 at the time I bought it as well.  If I 

need to get the dataq part, so be it, but it doesn't has have as many 

capabilities as the Labjack.



Thanks,

David M.

Robert L. Nuckolls, III wrote:

 	  Quote: 	
		   At 10:26 AM 2/2/2011, you wrote:

> 

>

> Bob,

>

> Interesting.  I plan to put a pair of P-Mags on the Lycoming for my 

> Toot.

>

> Rather than bare wires under a screw, I'd think about crimping a 

> suitably sized  ring terminal onto the wire with proper shrink tube 

> and placing the ring under the screw along with a lock washer.

>

> Others, please chime in if there's an error in my thinking as it's 

> info I'll eventually need.



   Just so we're all on the same page . . .



   The twist-n-squash terminal strips featured in this

   thread are probably the best there is for taking

   wires to etched circuit boards with convenience,

   minimum cost and reliability . . . UNDER CERTAIN

   CONDITIONS. Here's one example of the technology:



 Emacs!



   Here's one of my favorite $100 data acquisition modules that

   uses the same terminal strip.



 Emacs!



    Note that the bared end of a wire is NOT captured by

    a head of the mash-screw . . .



 Emacs!



    But by the END of the mash-screw. Further, there is a buffer

    strip between the wire strands and the end of the screw. If one

    REALLY needs to use a twist-n-squash technology, this is one of

    the best.



    Legacy design goals for aviation (and other disciplines)

    have adopted processes that offer gas-tightness in the

    metallic joints of the current carrying pathway along

    with wire support immediately adjacent to the gas-tight

    joint that prevents failure of the wire under vibration.



    Without getting in too much of a dither about new design

    goals, I think the best application of this process calls

    for parallel strands of wire pressed into the lower

    concave surface of the cavity with force from above

    offered by the screw. Then supply bundle support within

    a couple inches of the squash-joints.



    Note that is NOT what I did on this particular example . . .

    but then this DAM isn't expected to be in place and

    functioning after what we hope is decades of otherwise

    unattended service.



   Bob . . .




	


-- 

If you're an American, just say NO to the Obamanation, to socialism, and get rid of Soros.

nuckolls.bob(at)aeroelect
Guest

Posted: Thu Feb 03, 2011 1:01 pm Post subject: wire squash connections

At 11:45 AM 2/3/2011, you wrote:

 	  Quote: 	
		  



Bob, can you tell if the Labjack U12, www.labjack.com/U12 , is 

suitable?  I had no idea that termination was such a concern.  I've 

had the U12 for several years and hope to use it in my Mustang II 

(Mustang2.)  It was only $100 at the time I bought it as well.


	


   Suitable for what task?  How do you intend to use

   the device and what effects might failure of the

   device have on the outcome of any given flight.



   I believe the U12 is available as a bare-foot board

   assembly that has no i/o terminal strip or housing.

   You can solder your own i/o termination technology

   to the board. But even so, you need to think through

   the FMEA for having this board fail to accomplish

   any given task.



If I need to get the dataq part, so be it, but it doesn't has have as 

many capabilities as the Labjack.



   The DataQ device has the SAME terminal strips. The

   pictures showed how I reduced the inconvenience of

   of those strips with a D-sub connection adaptation . . .

   but the strips are still there.



   Unless you're using this board to develop feedback

   data for an autopilot or fuel injection system,

   then I suspect that failure to perform is nothing

   worse than a maintenance event. EITHER product will

   offer good value.

   Bob . . .

ainut(at)knology.net
Guest

Posted: Thu Feb 03, 2011 5:02 pm Post subject: wire squash connections

My purposes for this unit are pressures (turbo (3), air(2), water, and 

oil), misc switches, and possibly duct placements with the analog outs.  

I also intend to use the AMD 494/495 chips with thermocouples for 

temps.  No system critical functions will be used with this a/d unit.

I intend to use a megasquirt family device for engine controls and rpm 

reporting, etc.

Thanks,

David

Robert L. Nuckolls, III wrote:

 	  Quote: 	

 <nuckolls.bob(at)aeroelectric.com>

 At 11:45 AM 2/3/2011, you wrote:

> 

>

> Bob, can you tell if the Labjack U12, www.labjack.com/U12 , is 

> suitable?  I had no idea that termination was such a concern.  I've 

> had the U12 for several years and hope to use it in my Mustang II 

> (Mustang2.)  It was only $100 at the time I bought it as well.

   Suitable for what task?  How do you intend to use

   the device and what effects might failure of the

   device have on the outcome of any given flight.

   I believe the U12 is available as a bare-foot board

   assembly that has no i/o terminal strip or housing.

   You can solder your own i/o termination technology

   to the board. But even so, you need to think through

   the FMEA for having this board fail to accomplish

   any given task.

 If I need to get the dataq part, so be it, but it doesn't has have as 

 many capabilities as the Labjack.

   The DataQ device has the SAME terminal strips. The

   pictures showed how I reduced the inconvenience of

   of those strips with a D-sub connection adaptation . . .

   but the strips are still there.

   Unless you're using this board to develop feedback

   data for an autopilot or fuel injection system,

   then I suspect that failure to perform is nothing

   worse than a maintenance event. EITHER product will

   offer good value.

   Bob . . .

-- 

If you're an American, just say NO to the Obamanation, to socialism, and get rid of Soros.

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