USB microscopes for very small SMT

Beautiful

I wasn't thinking of that kind of TDR... there's tons of cheap handheld cable-TV-type TDRs around already. I was thinking of something for PC boards, with risetime in the 50 ps range and a total range of 50 ns maybe. That would resolve short traces and vias. You could sell it to pcb houses and anybody who buys and works on fast boards.

TDR is cool for certain components tests, too.

John

I had an uncle (mother's brother) who did his 20 years in the Navy, retired, did 20 years in the Army, retired, then became Sheriff of Killeen, TX ;-)

During his stint in the Army he eventually became a dental assistant at Fort Hood.

He had a fist-sized chunk of gold as a paper weight, from saving removed crowns ;-)

...Jim Thompson

How did you go about tinning it? Just lay some solder on it and wave a torch over it for a bit until it melts, and then whack it vertically or something to get any large globs off?

Clean it with Scotchbrite, then just tin it with a high-power Metcal iron. A dab of liquid flux helps spread the solder thin.

John

Nobody sane has thrown out machining cuttings for decades, the recycle value has been way too high. Hell, even in school on the 1960's it was standard.

I've seen it done. In machine shops. Sometimes I asked why. Too much hassle, they said :-(

I bet you know people who would like to supplement their income by doing the recycling for them. Try getting them together.

There's the little issue of coolant on the swarf-- better make sure you're not becoming an unlicensed toxic waste handler. 8-(.

Best regards, Spehro Pefhany

Possible issue for sure. But then the machining company has some "'splaining to do". You won't know until you ask. Besides, if there is any problem waste incorporated in the swarf it must go to a properly licensed facility (in the USA and most of Europe).