great site

I just ran across this yesterday, and it has a lot of really great information:

http://workmanship.nasa.gov

We have learned a lot of electronics lessons the hard way, generally 
finding that (unlike, say, peroxide use and handling) that you really do 
need to pay heed to all the horror stories people tell.

I would be interested in hearing about ERPS general practices for 
electrical fabrication work.

One lesson for us that has been driven home many times is:  Don't use 
anything but Tefzel wire.  I have specifically seen at least four failures 
in cheaper wiring due to heat or abrasion that  wouldn't have happened with 
Tefzel.  All my general 18g wiring has been Tefzel for a long time, but 
until recently I didn't have a good supply of heavier and lighter gauges, 
and I sometimes used cheaper wire.  When I recently reworked the 
electronics, I found a power wire with the conductor clearly visible for 
over a half inch.  We still have cheap wire coming off of some of our 
devices, which occasionally causes me some concern.  When you use Tefzel 
wiring, don't even think about using cheap wire crimpers, or it will drive 
you mad.  A good pair of moving jaw strippers makes all the difference in 
the world.

Another thing that bit us at least twice was bare wire screw terminals.  We 
put ring terminals on everything we make, but things like A/D breakout 
boards are almost always bare wire terminals.  We are having a custom board 
made to replace the breakout board, also adding some filtering and static 
protection.

The recently diagnosed inductive motor drive problems have probably caused 
us at least a half dozen flight test problems.

Our next rev of the electronics systems is going to use shielded and 
grounded cables for everything, which is going to be more of a hassle, but 
I will feel more comfortable about it.  We are also going to use shielded 
metal enclosures instead of building on plastic or composite bases.

John Carmack