NASA's Through-Hole Workmanship Req (2002) • Hacker News Board

Re: NASA's Through-Hole Workmanship Req (2002)

#11

Post by konschubert » Thu, Dec 17, 2020, 2:17 PM UTC

cushychicken wrote: post #6

konschubert wrote: post #5

I knew I was bad at soldering, I didn't know I was THAT bad. I need to take a course.

Keep in mind: this stuff has to be as close to perfect as possible because lives depend on it. Unless you're sending your stuff to space, I suspect you can cut yourself a bit of slack here. :)

The fact that my components keep failing says otherwise. ;)

Re: NASA's Through-Hole Workmanship Req (2002)

#12

Post by js2 » Thu, Dec 17, 2020, 2:17 PM UTC

Wire splicing:

https://workmanship.nasa.gov/lib/insp/2%20books/links/sectio...

Re: NASA's Through-Hole Workmanship Req (2002)

#13

Post by audiometry » Thu, Dec 17, 2020, 2:44 PM UTC

These high standards aren't unique to NASA. These few days I've been taking a micro-soldering course taught by Hakko. They are teaching standards IEC61191/JISC61191 (Japan Welding Society standard) and a lot of details are similar.

Re: NASA's Through-Hole Workmanship Req (2002)

#14

Post by audiometry » Thu, Dec 17, 2020, 2:45 PM UTC

heyflyguy wrote: post #2

Every now and again this pops up on a different forum. I wonder how much is actually hand soldered any more vs. pick and place machines with SMT.

I've been told that in areas where lots of prototyping isgoing on, there is lots of scope for manual rework. (a pcb design only 95% correct needs modifications to figure out the right design)

Re: NASA's Through-Hole Workmanship Req (2002)

#15

Post by tsomctl » Thu, Dec 17, 2020, 2:54 PM UTC

shireboy wrote: post #9

Anybody have tips on how to get to this level of solder-fu?

Flux, practice, flux, good tools, flux, good lighting, flux.

Really, learning how to braze and weld steel helped me a lot. Heat control is extremely important. Heat flows, and you learn how to position your iron to get the heat where you need it. You can also tell how hot something is by how the puddle looks.

Re: NASA's Through-Hole Workmanship Req (2002)

#16

Post by inamberclad » Thu, Dec 17, 2020, 2:57 PM UTC

shireboy wrote: post #9

Anybody have tips on how to get to this level of solder-fu?

Heat control. Cleanliness. High quality tools and solder.

Re: NASA's Through-Hole Workmanship Req (2002)

#17

Post by DanBC » Thu, Dec 17, 2020, 3:07 PM UTC

shireboy wrote: post #9

Anybody have tips on how to get to this level of solder-fu?

Basic soldering is easy to improve with practice. A couple of hours with a few hundred assorted components and some scrap PCBs will help to perfect the steps (tin the bit, hold the bit to the joint, apply the solder, pull the solder wire away, pull the bit away, inspect the joint). Things are a little bit trickier today because the alloy of the solder and the flux you use do make a difference, but lead-free solder today is very good.

Then practice with PVC insulated wire. The PVC insulation shrinks if it gets hot so this is good practice at speeding up.

I looked through the NASA document and most of it is not advance technique.

EDIT: people are saying "good tools" and I wanted to say a bit more about that. You can buy an iron for a few dollars from ebay. Don't use those. But almost any iron above that is going to be fine. I'd prefer to always be using Weller or Hako, but failing that any of the chinese no-name irons with temperature control are going to be good enough for most hobbyist projects. I love my Lindstrom and Bahco snips, but you can get good-enough cutters much cheaper. If this is something you're going to be doing all day every day you'll want to invest in the tools.

Re: NASA's Through-Hole Workmanship Req (2002)

#18

Post by phkahler » Thu, Dec 17, 2020, 3:44 PM UTC

audiometry wrote: post #14

heyflyguy wrote: post #2

Every now and again this pops up on a different forum. I wonder how much is actually hand soldered any more vs. pick and place machines with SMT.

I've been told that in areas where lots of prototyping isgoing on, there is lots of scope for manual rework. (a pcb design only 95% correct needs modifications to figure out the right design)

We had a board where somehow the footprint of an 8 pin SOIC got flipped in the layout. One engineer was able to desolder it, flip it, and solder it on using wires so that it floated about 1-2 cm above the board upside down. I was impressed ;-)

Re: NASA's Through-Hole Workmanship Req (2002)

#19

Post by NDizzle » Thu, Dec 17, 2020, 3:49 PM UTC

konschubert wrote: post #5

I knew I was bad at soldering, I didn't know I was THAT bad. I need to take a course.

Yeah. Damn. I hope nobody at NASA looks at some of the repairs I've had to make on my riding mower. I blame the work angles of some of those jobs...

Re: NASA's Through-Hole Workmanship Req (2002)

#20

Post by gte525u » Thu, Dec 17, 2020, 3:50 PM UTC

jcims wrote: post #8

Was curious what their treatment was going to be regarding tin whiskers. Not much there (of course this is point in time inspection so it kind of makes sense), but a quick google revealed quite a bit of study: https://nepp.nasa.gov/whisker/ I thought they were just one of those low probability items until a Sunday morning when I was running live audio for a church service. Singer was mid verse and BOOOOM! Huge boomin…

NASA and aviation in general are later adopters of lead-free. It definitely wouldn't have been reflected in older standards.