Solder Lug Design (?) - Resources & Suggestions

[Ben Bradley]

In sci.electronics.design, SAdams@frontiernet.net (Sean-Michael Adams)
wrote:

Hi folks.

I'm trying to find out more about the "proper" design of solder lugs
and wonder if there are any resources available on-line or if anyone
has any suggestions.

I'm at the very basic level of "what size hole is ideal? (based on
wire gage I'm sure)", "do you want the hole near an edge to keep the
thermal mass low?", "what can be designed into the lug to make it
'manufacturing friendly'?", etc.

I'm from the mech-design side of things and am not too savvy on the
nuances of electrical terminations (particularly the design of solder
lugs), so my goal is to get a little education and hopefully design a
termination that an electronics tech would be pleased with.

I don't get this. Are solder lugs still in common use? I definitely
remember them in Heathkits, but that was a long, long time ago.
Perhaps for someone making a device using one or one a very few
chassis, solder lugs and/or terminal strips (remember those?) might be
useful, but I can't imagine them being used for production anymore.
Wire ends are more easily terminated with washer-like ends that are
quickly screwed to a chassis, or push-on connections, as on speaker
terminals or appliances such as clothes wasters and dryers, are used.

Thanks for any advice,

SMA

-----
http://mindspring.com/~benbradley

 

[John Larkin]

On Mon, 05 Apr 2004 22:17:44 -0400, Ben Bradley
<ben_nospam_bradley@mindspring.example.com> wrote:

In sci.electronics.design, SAdams@frontiernet.net (Sean-Michael Adams)
wrote:

Hi folks.

I'm trying to find out more about the "proper" design of solder lugs
and wonder if there are any resources available on-line or if anyone
has any suggestions.

I'm at the very basic level of "what size hole is ideal? (based on
wire gage I'm sure)", "do you want the hole near an edge to keep the
thermal mass low?", "what can be designed into the lug to make it
'manufacturing friendly'?", etc.

I'm from the mech-design side of things and am not too savvy on the
nuances of electrical terminations (particularly the design of solder
lugs), so my goal is to get a little education and hopefully design a
termination that an electronics tech would be pleased with.

I don't get this. Are solder lugs still in common use? I definitely
remember them in Heathkits, but that was a long, long time ago.
Perhaps for someone making a device using one or one a very few
chassis, solder lugs and/or terminal strips (remember those?) might be
useful, but I can't imagine them being used for production anymore.
Wire ends are more easily terminated with washer-like ends that are
quickly screwed to a chassis, or push-on connections, as on speaker
terminals or appliances such as clothes wasters and dryers, are used.

I don't think I've designed in a solder lug in a decade or two. Wire
ends are almost always crimped or stomped into IDC connectors.

Yes, "IDC Connector" is a redundancy, like ATM Machine or LCD Display.


John

 

[Sean-Michael Adams]

Thanks folks for those who answered. What I'm working on is a power
transfer system and because of spatial constaraints and an inherited
envelope I could not easily use something like a crimped fast-on lug,
rings & spades are out as there is no screw to fasten to, etc.

My material is 1.5mm thick with 14 gage wire. I got a .100 thru hole
on the center of a 6mm wide tongue, 3mm from the edge.

I was hoping to glean some common wisdom like "take the wire gage and
go .020 over on the hole so that the solder will wick into the hole. .
.." Things like that. Keep the mass low because of heat absorption,
or . . .

I don't think I've designed in a solder lug in a decade or two.

While I find this very believable, did you have any rules of thumb
that you followed when you did?

I havn't run a shaper in 20 years but I still could give some good
advice on how to make some really nice chips and keep yourself from
making a trapezoidal block.

Thanks,

Sean

 

[Tim Shoppa]

SAdams@frontiernet.net (Sean-Michael Adams) wrote in message news:<7ff76910.0404062145.27fcc83e@posting.google.com>...

Thanks folks for those who answered. What I'm working on is a power
transfer system and because of spatial constaraints and an inherited
envelope I could not easily use something like a crimped fast-on lug,
rings & spades are out as there is no screw to fasten to, etc.

My material is 1.5mm thick with 14 gage wire. I got a .100 thru hole
on the center of a 6mm wide tongue, 3mm from the edge.

I was hoping to glean some common wisdom like "take the wire gage and
go .020 over on the hole so that the solder will wick into the hole. .
." Things like that. Keep the mass low because of heat absorption,
or . . .

1.5mm seems exceptionally thick for the thickness of a solder lug. Or
is that the thickness of what you want to attach the lug to?

Typical solder lug material is 0.020" (0.5mm) for the thickest I
commonly encounter. (For example, Keystone #7332).

Assuming that this is the lug on the edge of a larger bracket, etc:
It sounds to me like you want to just buy a regular solder lug and screw it to
your 1.5mm thick material. Off-the-shelf solder lugs are available with
different kinds of tails to deal with various accessibility issues, I'd
be surpsed if you couldn't work something in somewhere. If you don't
have room to put an off-the-shelf solder lug in so that you have to solder
the wire straight to some other part, I'd be very critical about you having
enough room to solder, deflux, and inspect a soldered wire connection.

Solder lugs are typically tin-plated brass and are generally
fairly easy to solder to. But I'm not the sheet-metal guy, I don't know
about solderability to random 1.5mm sheet-metal parts (especially
not tin-plated...)

Tim.

 

[Spehro Pefhany]

On 7 Apr 2004 05:24:46 -0700, the renowned shoppa@trailing-edge.com
(Tim Shoppa) wrote:

SAdams@frontiernet.net (Sean-Michael Adams) wrote in message news:<7ff76910.0404062145.27fcc83e@posting.google.com>...
Thanks folks for those who answered. What I'm working on is a power
transfer system and because of spatial constaraints and an inherited
envelope I could not easily use something like a crimped fast-on lug,
rings & spades are out as there is no screw to fasten to, etc.

My material is 1.5mm thick with 14 gage wire. I got a .100 thru hole
on the center of a 6mm wide tongue, 3mm from the edge.

I was hoping to glean some common wisdom like "take the wire gage and
go .020 over on the hole so that the solder will wick into the hole. .
." Things like that. Keep the mass low because of heat absorption,
or . . .

1.5mm seems exceptionally thick for the thickness of a solder lug. Or
is that the thickness of what you want to attach the lug to?

Typical solder lug material is 0.020" (0.5mm) for the thickest I
commonly encounter. (For example, Keystone #7332).

Assuming that this is the lug on the edge of a larger bracket, etc:
It sounds to me like you want to just buy a regular solder lug and screw it to
your 1.5mm thick material. Off-the-shelf solder lugs are available with
different kinds of tails to deal with various accessibility issues, I'd
be surpsed if you couldn't work something in somewhere. If you don't
have room to put an off-the-shelf solder lug in so that you have to solder
the wire straight to some other part, I'd be very critical about you having
enough room to solder, deflux, and inspect a soldered wire connection.

Solder lugs are typically tin-plated brass and are generally
fairly easy to solder to. But I'm not the sheet-metal guy, I don't know
about solderability to random 1.5mm sheet-metal parts (especially
not tin-plated...)

Tim.

Lots of these parts are made riveting onto other parts. Seems that the
material for making the lug is seldom suitable for doing the job of
what it's connected to. One exception I can think of is the brushes on
small DC motors.

For example:

http://www.seastrom-mfg.com/Seastrom_Manufacturing_Catalog/Engineering/eng-solderlugs.htm

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

 

[JeffM]

No, but then you didn't give me a 5-year scholarship.
John Larkin

Did that allow for a post-graduate sheepskin
or was the 5th year spend drinking and wenching
(with the other hours that year just wasted)?

 

[Spehro Pefhany]

On Wed, 07 Apr 2004 11:49:40 -0700, the renowned John Larkin
<jjlarkin@highSNIPlandTHIStechPLEASEnology.com> wrote:

On 7 Apr 2004 11:32:57 -0700, jeffm_@email.com (JeffM) wrote:

No, but then you didn't give me a 5-year scholarship.
John Larkin

Did that allow for a post-graduate sheepskin
or was the 5th year spend drinking and wenching
(with the other hours that year just wasted)?

Well, I had two jobs, and did do a bit of sailing and drinking and
wenching, and then got married and begat The First Brat, so it took 5
years to get a BSEE. That was all the education I could stand.

New Orleans *is* a party town.
John

If you saw it, does the movie "WUSA" portray it fairly?

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

 

[John Larkin]

On Wed, 07 Apr 2004 21:32:54 GMT, Spehro Pefhany
<speffSNIP@interlogDOTyou.knowwhat> wrote:

On Wed, 07 Apr 2004 11:49:40 -0700, the renowned John Larkin
jjlarkin@highSNIPlandTHIStechPLEASEnology.com> wrote:

On 7 Apr 2004 11:32:57 -0700, jeffm_@email.com (JeffM) wrote:

No, but then you didn't give me a 5-year scholarship.
John Larkin

Did that allow for a post-graduate sheepskin
or was the 5th year spend drinking and wenching
(with the other hours that year just wasted)?

Well, I had two jobs, and did do a bit of sailing and drinking and
wenching, and then got married and begat The First Brat, so it took 5
years to get a BSEE. That was all the education I could stand.

New Orleans *is* a party town.
John

If you saw it, does the movie "WUSA" portray it fairly?

Best regards,
Spehro Pefhany

Didn't see that one. New Orleans is a strange place, a
French/Latin/Carribean culture that happens to be located in the
South. It's a great place for fun and food and family, but you won't
find a machine shop that believes in holding tolerances. And don't
even think of using irony... they'll look at you like you're some sort
of idiot.

The Silicon Bayou thing, uh, didn't work out too well.

John