64 September 2017
>>>YOUR ELECTRONICS QUESTIONS ANSWERED HERE BY N&V READERS
#5 It’s a crapshoot. I worked on
three Chinese sets in a row that were
junk, then came to one that was
excellent. Other techs report similar
[#6171 - June 2017]
Miniature Parts Needed
I’ve been tearing down Seiko
solar quartz watches in search of small
efficient engines to power miniature
robots. Can anyone recommend a
source for additional components,
such as miniature axles and wheels?
You might try old auto-focus
cameras and similar equipment. Old
micro-cassette players too. These all
generally have a bunch of small shafts
and pulleys; you could take one of
the small pulleys and add a miniature
o-ring as a tire.
Another possibility — maybe
even better — would be those small
micro remote control cars which were
popular a few years back. Or, maybe
small slot-cars or N-gauge trains.
Another possibility for a tire
might be a slice of pencil eraser.
Super-glue it to a small piece of piano
wire or similar for the shaft.
[#6172 - June 2017]
What To Do With Leaded Solder
I have a bunch of 2 lb rolls of
leaded solder that I no longer plan to
use, given the availability of lead-free
solder. How should I dispose of the
solder? Is it considered hazardous
waste due to the lead?
#1 If you are a hobbyist, why not
just use it. Unless you are selling a
product in high volume, you’re not
going to distroy the world. Plus, it’s so
much better than the lead-free stuff.
#2 Most countries would consider
it hazardous — as you surmise — and
it should be disposed of responsibly,
according to local regs. (Whoever
accepts dead car batteries should
take it for free possibly.)
Should you even get rid of it all?
The fact that you have it indicates
you’re interested in electronics —
either for repair or construction. The
important point I’m trying to make is
that the two types of solder don’t play
well together. So, for reliability, older
equipment should only be soldered
with leaded solder (and vice versa).
Do some Googling to check it
out. Don’t use plumbing lead-free
solder for electronics, either! If you’re
giving up the hobby, that's a shame,
but so be it.
#3 Leaded solder is still available
and widely used — both in aerospace
and in the repair and rework of
older equipment that was made
with leaded solder. Many hobbyists
(including myself) prefer leaded
solder because it flows better and
makes much nicer joints. As long
as you don’t chew on it and are
not disposing of millions of tons of
equipment made with it, there is not
really a hazard in having or using it. If
you don’t want it, I would encourage
you to give it to somebody else or
alternately you could sell it on eBay.