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Resistor and capacitor installation techniques: trim before or after soldering?

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Resistor and capacitor installation techniques: trim before or after soldering?

Jerome,

Now this is interesting. This is totally opposite of the way most of us
were taught to solder. Among the kits I used to put together were Heathkit
and Ramsey, both of whom recommended securing the parts in place by
spreading the leads, soldering, and then cutting the wires close to the
solder blob, checking for shorts. I assume that goes for Elecraft also, but
I have not built any of their radios as kits, so not sure.

So how did NASA handle the potential difficulties? Did they have precut
parts? Did the tech have to place the part in the board and cut the leads
first? If the part was loose, how was it held close to the board, owing to
the fact that holding the solder and the iron took two hands? What if the
lead length was overestimated and potentially could cause a short? Could
the wire be cut and the joint reheated, or did the part have to be removed,
recut and reinserted?

Just trying to picture the operation.

'73 de JIM N2ZZ

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of JEROME SODUS
Sent: Saturday, March 24, 2018 11:40 PM
To: [hidden email]
Subject: Re: [Elecraft] Resistor and capacitor installation techniques: trim
before or after soldering?

About Message#15 copied below....

Sorry but cutting wires after soldering is "bad practice"; NASA wanted the
soldered connection left undisturbed.

If I ever saw an assembler or tech doing that "bad practice", they'd get a
verbal warning that first time and a written warning if it ever happened
again; but I had good, conscientious people and never had to do that.

So, tin the wires if needed; position the part and then trim wires before
doing the final soldering.

73 Jerry KM3K

Message: 15
Date: Sat, 24 Mar 2018 19:39:47 +0000
From: Bill Johnson <[hidden email]>
To: "[hidden email]" <[hidden email]>, 'Mark Petrovic'
<[hidden email]>, "[hidden email]"
<[hidden email]>
Subject: Re: [Elecraft] Resistor and capacitor installation
techniques: trim before or after soldering?
Message-ID:
<[hidden email]
OM>

Content-Type: text/plain; charset="us-ascii"

Follow the instructions and solder as directed. There are components on both
sides as I recall with the majority on the top. The leads need be spread to
hold the components in place on the board. Once done soldering use a flush
cut wirecutter to remove the excess. Not a good idea to trim them before
soldering.

72 & 73,
Bill
K9YEQ
FT'er for K2, KX1, KX3, KXPA100, KAT500, W2, etc.
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Doug Renwick

Re: Resistor and capacitor installation techniques: trim before or after soldering?

Heathkit recommended the "bad practice" saying "solder the leads to the foil
and cut off the excess lead lengths". Reprimanding a technician for doing
this is insane.
Doug

"Political correctness is a weapon used to silence people who tell the
truth" - Ayaan Hirsi Ali

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of James F. Boehner MD
via Elecraft
Sent: March-25-18 9:33 AM
To: 'JEROME SODUS'; [hidden email]
Subject: [Elecraft] Resistor and capacitor installation techniques:
trimbefore or after soldering?

Jerome,

Now this is interesting. This is totally opposite of the way most of us
were taught to solder. Among the kits I used to put together were Heathkit
and Ramsey, both of whom recommended securing the parts in place by
spreading the leads, soldering, and then cutting the wires close to the
solder blob, checking for shorts. I assume that goes for Elecraft also, but
I have not built any of their radios as kits, so not sure.

So how did NASA handle the potential difficulties? Did they have precut
parts? Did the tech have to place the part in the board and cut the leads
first? If the part was loose, how was it held close to the board, owing to
the fact that holding the solder and the iron took two hands? What if the
lead length was overestimated and potentially could cause a short? Could
the wire be cut and the joint reheated, or did the part have to be removed,
recut and reinserted?

Just trying to picture the operation.

'73 de JIM N2ZZ

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of JEROME SODUS
Sent: Saturday, March 24, 2018 11:40 PM
To: [hidden email]
Subject: Re: [Elecraft] Resistor and capacitor installation techniques: trim
before or after soldering?

About Message#15 copied below....

Sorry but cutting wires after soldering is "bad practice"; NASA wanted the
soldered connection left undisturbed.

If I ever saw an assembler or tech doing that "bad practice", they'd get a
verbal warning that first time and a written warning if it ever happened
again; but I had good, conscientious people and never had to do that.

So, tin the wires if needed; position the part and then trim wires before
doing the final soldering.

73 Jerry KM3K

Message: 15
Date: Sat, 24 Mar 2018 19:39:47 +0000
From: Bill Johnson <[hidden email]>
To: "[hidden email]" <[hidden email]>, 'Mark Petrovic'
<[hidden email]>, "[hidden email]"
<[hidden email]>
Subject: Re: [Elecraft] Resistor and capacitor installation
techniques: trim before or after soldering?
Message-ID:
<[hidden email]
OM>

Content-Type: text/plain; charset="us-ascii"

Follow the instructions and solder as directed. There are components on both
sides as I recall with the majority on the top. The leads need be spread to
hold the components in place on the board. Once done soldering use a flush
cut wirecutter to remove the excess. Not a good idea to trim them before
soldering.

72 & 73,
Bill
K9YEQ
FT'er for K2, KX1, KX3, KXPA100, KAT500, W2, etc.
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Don Wilhelm

Re: Resistor and capacitor installation techniques: trim before or after soldering?

In reply to this post by Elecraft mailing list

I agree, the stated NASA "method" does amaze me.
First, the K2 is not likely to go a space journey.

Components with pre-cut leads may require 3 hands. One to hold the
component, one to hold the soldering iron and another to hold the solder.
I would assume that NASA directive was for wave-soldering boards and
does not apply to hand soldering.

I personally have a guideline which says "do not ever trim an unsoldered
lead" - watch as you trim and go back and solder it.

Of course, I am one who inserts multiple components before soldering.

I have never seen a failed solder connection in my work nor had any
reports of solder joint failure from those I have built the K2, K1, KX1
or XVseries transverters.

73,
Don W3FPR

On 3/25/2018 11:33 AM, James F. Boehner MD via Elecraft wrote:

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Art Greenberg

Re: Resistor and capacitor installation techniques: trim before or after soldering?

I guess if you're building something that goes into a spacecraft or is life support equipment, you want to do everything you can to make the product as reliable as possible. In most cases, ham gear, especially hand assembled ham gear, doesn't fall into that category.

Mass produced through-hole assembly where the PCB is wave soldered requires the parts to be held in place and leads trimmed prior to soldering. I recall a "staking" tool that would flatten the component lead very close to the PCB and trim off the excess in one operation.

Replacing parts where the components were staked in is a PITA.

--
Art Greenberg
WA2LLN
[hidden email]

On Sun, Mar 25, 2018, at 12:18, Don Wilhelm wrote:

> I agree, the stated NASA "method" does amaze me.
> First, the K2 is not likely to go a space journey.
>
> Components with pre-cut leads may require 3 hands. One to hold the
> component, one to hold the soldering iron and another to hold the solder.
> I would assume that NASA directive was for wave-soldering boards and
> does not apply to hand soldering.
>
> I personally have a guideline which says "do not ever trim an unsoldered
> lead" - watch as you trim and go back and solder it.
>
> Of course, I am one who inserts multiple components before soldering.
>
> I have never seen a failed solder connection in my work nor had any
> reports of solder joint failure from those I have built the K2, K1, KX1
> or XVseries transverters.
>
> 73,
> Don W3FPR
>
>
> On 3/25/2018 11:33 AM, James F. Boehner MD via Elecraft wrote:
> > Jerome,
> >
> > Now this is interesting. This is totally opposite of the way most of us
> > were taught to solder. Among the kits I used to put together were Heathkit
> > and Ramsey, both of whom recommended securing the parts in place by
> > spreading the leads, soldering, and then cutting the wires close to the
> > solder blob, checking for shorts. I assume that goes for Elecraft also, but
> > I have not built any of their radios as kits, so not sure.
> >
> > So how did NASA handle the potential difficulties? Did they have precut
> > parts? Did the tech have to place the part in the board and cut the leads
> > first? If the part was loose, how was it held close to the board, owing to
> > the fact that holding the solder and the iron took two hands? What if the
> > lead length was overestimated and potentially could cause a short? Could
> > the wire be cut and the joint reheated, or did the part have to be removed,
> > recut and reinserted?
> >
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
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David Olean

Re: Resistor and capacitor installation techniques: trim before or after soldering?

In reply to this post by Elecraft mailing list

I was NASA certified to solder components back in the late 60's. I don't
remember much except that stripping wires teflon wires required thermal
wire strippers, and each solder joint used the minimum amount of solder
and wires were wrapped around terminals for a specified number of
degrees. The meniscus formed by the solder joint had to be concave. All
flux had to be removed with ethyl alcohol. All in an effort to reduce
weight of the total package and still be reasonably solid to pass the
shake tests. I would never use NASA techniques for normal solder jobs.
There is something to be said about .062 or .125 rolls of solder and
big lumps of solder on the joints! :-).

Dave K1WHS (solder blob expert!)

On 3/25/2018 3:33 PM, James F. Boehner MD via Elecraft wrote:

> Jerome,
>
> Now this is interesting. This is totally opposite of the way most of us
> were taught to solder. Among the kits I used to put together were Heathkit
> and Ramsey, both of whom recommended securing the parts in place by
> spreading the leads, soldering, and then cutting the wires close to the
> solder blob, checking for shorts. I assume that goes for Elecraft also, but
> I have not built any of their radios as kits, so not sure.
>
> So how did NASA handle the potential difficulties? Did they have precut
> parts? Did the tech have to place the part in the board and cut the leads
> first? If the part was loose, how was it held close to the board, owing to
> the fact that holding the solder and the iron took two hands? What if the
> lead length was overestimated and potentially could cause a short? Could
> the wire be cut and the joint reheated, or did the part have to be removed,
> recut and reinserted?
>
> Just trying to picture the operation.
>
> '73 de JIM N2ZZ
>
> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of JEROME SODUS
> Sent: Saturday, March 24, 2018 11:40 PM
> To: [hidden email]
> Subject: Re: [Elecraft] Resistor and capacitor installation techniques: trim
> before or after soldering?
>
> About Message#15 copied below....
>
> Sorry but cutting wires after soldering is "bad practice"; NASA wanted the
> soldered connection left undisturbed.
>
> If I ever saw an assembler or tech doing that "bad practice", they'd get a
> verbal warning that first time and a written warning if it ever happened
> again; but I had good, conscientious people and never had to do that.
>
> So, tin the wires if needed; position the part and then trim wires before
> doing the final soldering.
>
> 73 Jerry KM3K
>
>
>
> Message: 15
> Date: Sat, 24 Mar 2018 19:39:47 +0000
> From: Bill Johnson <[hidden email]>
> To: "[hidden email]" <[hidden email]>, 'Mark Petrovic'
> <[hidden email]>, "[hidden email]"
> <[hidden email]>
> Subject: Re: [Elecraft] Resistor and capacitor installation
> techniques: trim before or after soldering?
> Message-ID:
> <[hidden email]
> OM>
>
> Content-Type: text/plain; charset="us-ascii"
>
> Follow the instructions and solder as directed. There are components on both
> sides as I recall with the majority on the top. The leads need be spread to
> hold the components in place on the board. Once done soldering use a flush
> cut wirecutter to remove the excess. Not a good idea to trim them before
> soldering.
>
> 72 & 73,
> Bill
> K9YEQ
> FT'er for K2, KX1, KX3, KXPA100, KAT500, W2, etc.
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html Message
> delivered to [hidden email]
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]
>

N2TK

Re: Resistor and capacitor installation techniques: trim before or after soldering?

In reply to this post by Doug Renwick

Hi Jim,
Doug is correct about military and space work. All parts are precut or have
spacers installed prior to board mounting. Between flux, solder/flux and
mechanical means the parts are held in place until the reflow oven. For some
programs, boards are not allowed to be reworked. Some programs allow rework.
There is a very detailed procedure for reworking a board - MIL-PRF-38535 and
MIL-STD-883.

But, our applications and most commercial applications do not see the
stress, temperature range or vibration that some of these mil and space
boards see. So, for most of us bending the leads to hold the part, solder
and cut is fine. You can re-solder after cutting to be sure.

Years ago at a NASA meeting, they were told you do not need a tool meeting
MIL-STD and MIL-PRF to make a board that meets those specs. So, have the
right solder and right temp on the soldering tool and the right tip and make
a nice flowing shiny solder connection.
By the way, military space solder is not RoHS compliant. There will be lead
in the solder.

73,
N2TK, Tony

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Doug Renwick
Sent: Sunday, March 25, 2018 12:05 PM
To: 'James F. Boehner MD' <[hidden email]>; 'JEROME SODUS'
<[hidden email]>; [hidden email]
Subject: Re: [Elecraft] Resistor and capacitor installation techniques: trim
before or after soldering?

Heathkit recommended the "bad practice" saying "solder the leads to the foil
and cut off the excess lead lengths". Reprimanding a technician for doing
this is insane.
Doug

"Political correctness is a weapon used to silence people who tell the
truth" - Ayaan Hirsi Ali

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of James F. Boehner MD
via Elecraft
Sent: March-25-18 9:33 AM
To: 'JEROME SODUS'; [hidden email]
Subject: [Elecraft] Resistor and capacitor installation techniques:
trimbefore or after soldering?

Jerome,

Now this is interesting. This is totally opposite of the way most of us
were taught to solder. Among the kits I used to put together were Heathkit
and Ramsey, both of whom recommended securing the parts in place by
spreading the leads, soldering, and then cutting the wires close to the
solder blob, checking for shorts. I assume that goes for Elecraft also, but
I have not built any of their radios as kits, so not sure.

So how did NASA handle the potential difficulties? Did they have precut
parts? Did the tech have to place the part in the board and cut the leads
first? If the part was loose, how was it held close to the board, owing to
the fact that holding the solder and the iron took two hands? What if the
lead length was overestimated and potentially could cause a short? Could
the wire be cut and the joint reheated, or did the part have to be removed,
recut and reinserted?

Just trying to picture the operation.

'73 de JIM N2ZZ

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of JEROME SODUS
Sent: Saturday, March 24, 2018 11:40 PM
To: [hidden email]
Subject: Re: [Elecraft] Resistor and capacitor installation techniques: trim
before or after soldering?

About Message#15 copied below....

Sorry but cutting wires after soldering is "bad practice"; NASA wanted the
soldered connection left undisturbed.

If I ever saw an assembler or tech doing that "bad practice", they'd get a
verbal warning that first time and a written warning if it ever happened
again; but I had good, conscientious people and never had to do that.

So, tin the wires if needed; position the part and then trim wires before
doing the final soldering.

73 Jerry KM3K

Message: 15
Date: Sat, 24 Mar 2018 19:39:47 +0000
From: Bill Johnson <[hidden email]>
To: "[hidden email]" <[hidden email]>, 'Mark Petrovic'
<[hidden email]>, "[hidden email]"
<[hidden email]>
Subject: Re: [Elecraft] Resistor and capacitor installation
techniques: trim before or after soldering?
Message-ID:
<[hidden email]
OM>

Content-Type: text/plain; charset="us-ascii"

Follow the instructions and solder as directed. There are components on both
sides as I recall with the majority on the top. The leads need be spread to
hold the components in place on the board. Once done soldering use a flush
cut wirecutter to remove the excess. Not a good idea to trim them before
soldering.

72 & 73,
Bill
K9YEQ
FT'er for K2, KX1, KX3, KXPA100, KAT500, W2, etc.
______________________________________________________________
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David Gilbert

Re: Resistor and capacitor installation techniques: trim before or after soldering?

In reply to this post by Don Wilhelm

I've soldered a LOT of components to circuit boards and I've always cut
the leads prior to soldering.

I insert the component and flip the board over to see which direction
the runs go from the lead. I bend the lead in the direction of the run,
which serves the purpose of holding the component in place while I
insert more components and do the same to them. Once I have several
components installed I trim all the leads and solder them.

For me, this serves more than one purpose.

1. It holds the part securely in place prior to soldering.
2. The wire is pressed against the inside edge of the pad, which
facilitates solder flow at the connection.
3. I can get the tip of the soldering iron closer to the joint between
the lead and the pad by putting it opposite the direction the lead was bent.
4. It results in a MUCH lower profile on the back side of the board ...
which means less chance of something shorting in tight spaces.
5. I can more easily determine a bad solder joint. If the solder
doesn't wick along the run under the wire I know it didn't take. It's
easy to end up with rosin between the joint without noticing it when the
wire goes straight up.

The only downside I've ever had is like the other guy said ... it's a
total PITA to replace a component that has been soldered like that.

Dave AB7E

On 3/25/2018 9:18 AM, Don Wilhelm wrote:

> I agree, the stated NASA "method" does amaze me.
> First, the K2 is not likely to go a space journey.
>
> Components with pre-cut leads may require 3 hands. One to hold the
> component, one to hold the soldering iron and another to hold the solder.
> I would assume that NASA directive was for wave-soldering boards and
> does not apply to hand soldering.
>
> I personally have a guideline which says "do not ever trim an
> unsoldered lead" - watch as you trim and go back and solder it.
>
> Of course, I am one who inserts multiple components before soldering.
>
> I have never seen a failed solder connection in my work nor had any
> reports of solder joint failure from those I have built the K2, K1,
> KX1 or XVseries transverters.
>
> 73,
> Don W3FPR
>
>
> On 3/25/2018 11:33 AM, James F. Boehner MD via Elecraft wrote:
>> Jerome,
>>
>> Now this is interesting. This is totally opposite of the way most of us
>> were taught to solder. Among the kits I used to put together were
>> Heathkit
>> and Ramsey, both of whom recommended securing the parts in place by
>> spreading the leads, soldering, and then cutting the wires close to the
>> solder blob, checking for shorts. I assume that goes for Elecraft
>> also, but
>> I have not built any of their radios as kits, so not sure.
>>
>> So how did NASA handle the potential difficulties? Did they have precut
>> parts? Did the tech have to place the part in the board and cut the
>> leads
>> first? If the part was loose, how was it held close to the board,
>> owing to
>> the fact that holding the solder and the iron took two hands? What if
>> the
>> lead length was overestimated and potentially could cause a short?
>> Could
>> the wire be cut and the joint reheated, or did the part have to be
>> removed,
>> recut and reinserted?
>>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]
>