NASA Electronics Build Workmanship and Quality Standards - Page 1
Forum section: electronics / projects

author: nixfu
author_rank: Unknown
timestamp: August 28, 2014, 08:50:44 pm
content: Came across this interesting info. Its NASA standards for building electronics. Lots of great pictures on soldering standards etc. even for SMT work. Its worth a look see.http://workmanship.nasa.gov/lib/insp/2%20books/frameset.html

author: Skimask
author_rank: Super Contributor
timestamp: August 28, 2014, 10:45:37 pm
content: Yep, that's the stuff.Did a 6 week intensive training course on that stuff at Davis-Monthan in Tucson, Az. a few years back. Got 2M/CCR certified.Definitely not for anyone with shaky hands or no patience. It all looks fairly simple and doable in the pictures, but when you get down to actually performing the tasks, they're a big PITA to accomplish to 100% of the standards described in that (and other) documents.

author: rs20
author_rank: Super Contributor
timestamp: August 28, 2014, 11:34:43 pm
content: Quote from: nixfu on August 28, 2014, 08:50:44 pmCool, interesting to look through.One of themdid throw me off, though:"Part leads shall not be used as terminals, except when the part lead is used as a terminal."It's like "Don't do X, unless you do X" ?

author: zapta
author_rank: Super Contributor
timestamp: August 29, 2014, 12:25:01 am
content: Quote from: Skimask on August 28, 2014, 10:45:37 pmDoes it require fancy equipment or is it mostly a matter of skills?

author: jeremyabel
author_rank: Newbie
timestamp: August 29, 2014, 03:37:27 am
content: Ohhhh man this is some drool-worthy stuff! Wish they had a whole PDF and not just per-section PDFs though!

author: GeoffS
author_rank: Unknown
timestamp: August 29, 2014, 03:55:03 am
content: When I did my electronics training in the RAAF, the soldering part of the course was to a NASA standard -'High Reliability, Hand Soldering'Not sure if the instructors were certified but it was a tough course.I doubt I could manage it these days.

author: Skimask
author_rank: Super Contributor
timestamp: August 29, 2014, 03:56:13 am
content: Fancy brand new equipment sure was a nice change while I was in that classIt's more "clean" rather than fancy that gets the job done right.A decent temperature controlled soldering iron, with good heat capacity, using the right tip for the job, clean solder on clean parts. Those are the main tickets to good soldering.Even if you've got shaky hands, if you've got good heat with clean parts and materials, the solder will only flow where it can flow and needs to flow, and if you feed in the right amount of solder, you'll get a good joint. Period.At this school (and in the shop I used to run), we had PACE PRC-2000 stations with practically every tip imaginable...and I can imagine quite a few tips. Along with that, an almost unlimited supply of "Kim-Wipes", fresh lab quality iso-alcohol, fresh RMA flux, q-tips, a decent set of various dental tools, Meiji microscopes, and the list goes on.None of that stuff matters without clean equipment and parts.Even now, some 3+ years after I've retired from the USAF, I still try to hold myself to those standards in my own work.As for my soldering type equipment...Weller WESD51 soldering iron station with a handful of various tips"insert brand name here" 858D hot air gunZD-985 de-soldering toolA bin full of various dental tools. Brand new, they're all expensive. I go to a couple of local dentists once in awhile and ask them if I can look through (and take some of) their 'broken' dental tools. One time I paid the guy $20 for a handful of broken stuff. Most of those tools are have tips on both ends. One tip breaks, the whole tool is broke for them...not for me.A few quarts of fresh lab quality iso-alcohol along with a bunch of lint-free wipes and q-tips (cotton swabs) for cleaning.Fresh flux. I only keep a pint or so on hand. That way I have to order new stuff once in awhile...keep it fresh.Cheap $30 USB 'microscope' for inspection. Gonna upgrade that sooner or later with something like Dave's MANTIS scope.Good light source. I prefer a bunch of incandescent lights with reflectors. LEDs and Fluorescent lights aren't the right 'color' for my tastes.All in all, maybe $300 of equipment/material for a decent hobbyist bench.Can you get away with less? Sure. Just keep it clean.Want to spend more? Sure. Spent $100K on equipment. But if it isn't clean, a $50K soldering station won't make up the difference.

author: Skimask
author_rank: Super Contributor
timestamp: August 29, 2014, 03:58:00 am
content: Quote from: GeoffS on August 29, 2014, 03:55:03 amNo kidding right!I had to do yearly re-cert's up until a couple of years ago. The class was hard enough, but at least you had an instructor there to show you the errors of your way.The recertifications were totally self-paced and they gave you a week to do it all. Zero instructor assists. 100% pass or nothing.

author: calexanian
author_rank: Super Contributor
timestamp: August 29, 2014, 05:37:47 am
content: Bookmarked for future reference!

author: salbayeng
author_rank: Frequent Contributor
timestamp: August 29, 2014, 01:47:35 pm
content: Yep its a brilliant reference, found it about a year ago myself.

author: tom66
author_rank: Super Contributor
timestamp: August 29, 2014, 01:49:08 pm
content: Quote from: rs20 on August 28, 2014, 11:34:43 pmMaybe it means, "Don't do X, unless it is intended by the part to do X."

author: fpliuzzi
author_rank: Regular Contributor
timestamp: August 29, 2014, 02:48:24 pm
content: The wording in Section 6.01 of the document seems to clarify the situation...UNACCEPTABLEPART LEADS USED AS TERMINALSPart leads shall not be used as terminals, unless the part lead is designed to function as a terminal.NASA-STD-8739.3 [13.6.2.a.18]

author: Winston
author_rank: Regular Contributor
timestamp: August 29, 2014, 03:45:36 pm
content: Quote from: GeoffS on August 29, 2014, 03:55:03 amSame here in the USAF. It was a post-tech-school two-week course. It was called "NASA/mil-spec soldering." Some items used not typically used in hobby soldering:Also went to a two-week fiber optics course.

author: Skimask
author_rank: Super Contributor
timestamp: August 30, 2014, 02:28:10 am
content: Quote from: Winston on August 29, 2014, 03:45:36 pmNeat.... I did that class too back in '88 as a 1 striper. Barely got into a routine working the flight line and got sent over there.Never did get to do the fiber course though...

author: salbayeng
author_rank: Frequent Contributor
timestamp: August 30, 2014, 04:22:56 am
content: re"It's like "Don't do X, unless you do X" ?"Reminds me of the "NO STEP" placards on top of the aircraft wings at the overwing exits,it's like "don't step here unless you have to step here"

author: rs20
author_rank: Super Contributor
timestamp: August 30, 2014, 07:24:53 am
content: Quote from: salbayeng on August 30, 2014, 04:22:56 amWell, if the overwing doors are opened, I think avoiding damage to the skin of the aircraft is no longer a priority... those signs are for routine maintenance personnel, not escaping passengers.

author: Unknown
author_rank: Unknown
timestamp: August 30, 2014, 08:21:49 am
content: For those who want their own offline reference, I've combined all the sections into a single PDF file which is available at:https://db.tt/CAlbiGmsPlease download the file as I can't guarantee that I'll keep it in my Dropbox indefinitely. I didn't have time to build an index for it. Also be aware that the file is 282MB in size. This is deliberate in order to preserve the original resolution of the photos. I haven't applied any security to the file so you can compress it using Adobe Acrobat if required.Enjoy :-)

author: zapta
author_rank: Super Contributor
timestamp: August 30, 2014, 12:18:18 pm
content: Quote from: Winston on August 29, 2014, 03:45:36 pmGot a used TW-1 on eBay. Works great with Teflon wires.BTW, Teledyne had great service and spare parts availability.

author: amyk
author_rank: Super Contributor
timestamp: August 30, 2014, 01:11:08 pm
content: Keep in mind that these standards are for equipment whose failure may mean loss of life and substantial damage. On regular consumer electronics, such high standards would not be necessary and applying them would be extreme overkill.

author: SeanB
author_rank: Super Contributor
timestamp: August 30, 2014, 04:06:36 pm
content: No Step is for service use, used on things like thin sections and moving parts that may be damaged by point loads instead of regular aerodynamic loading. Also placed on access panel openings as these are often thinner than the surrounding skin and have a double layer of reinforcing to spread the load around them, but are weak in torsion.To work on aircraft you get special non marking soft soled shoes that you wear on the flight line so that you do not mark or damage the skin with hard soled rubber footwear, along with the soft soles being more resistant to softening if they get wetted with fuel or hydraulic fluid. Bad thing is they are very slippery on wet surfaces, so you tend to be careful on wet floors, as you can take a nasty fall.I used to get 2 pair a year, and as I was Instrumentation I had an exemption on polishing them, after somebody had a nasty incident involving freshly polished shoes and LOX. My cleaning regime involved regular application of matt black instrument panel spray paint to keep them looking good on inspection after a light going over with a scotchbrite pad.Note that in the safety instructions on any flight you will find that all women must remove high heel shoes before using the emergency exit slides or the overwing exits. Those shoes do damage to aircraft flooring even through the carpeting, as you can always see the walkways from underneath just from the dimples caused by high heels deforming the aluminium skin from the point load. That is why most flight attendants wear low heels, for the comfort and so that they can get out in training with dignity.