KI7TU's Reference Page -- Tools
On this page, I want to pass on some hard-won wisdom regarding tools
for the electronics hobbyist.
This wisdom comes from a combination of what I learned as a child
from my father who was a well-respected aircraft mechanic,
and from my own experience.
In general, getting good tools for your workbench is worthwhile.
A good tool will often last several decades, whereas a cheaper tool
may only last a few months (or in the worst case, only a few minutes).
Good tools may seem expensive, but if you can hang onto them and not
abuse them, they are usually a lot less expensive in the long run
than the cheap ones, though there are a few exceptions to this.
As always, no guarantees are made.
The soldering iron is often considered the quintesential tool of
electronics.
Having a decent one is worthwhile.
One widely held misconception is that you should use a fairly cool
soldering iron on printed circuit boards. In reality, a hotter,
higher wattage one will do less damage as it has the "oomph"
to get in and out quickly without transferring a lot of unwanted heat
to the surrounding parts of the board. The soldering iron I use for
"everyday" electronics is a 45 watt iron with a very fine
tip. Mine has both a replacable "cartridge" and a separate
tip. I got this in the early 80s. Mine was made by Ungar (unfortunately
long out of the business of making soldering irons), but there are
similar irons from Weller (and others). I would recommend looking for
one that has the tip grounded, in case you want to solder static
sensitive devices.
Please note that the above is my opinion based on
my experience. There are a lot of people
who are of the opinion that you should use a cooler iron on
small parts.
There are "soldering stations" around that control the
temperature of the tip. In my humble opinion, these are a waste of
money.
A good stand, though, is also a very wise investment. One that has
some weight to it, so it won't tip over, and a "cage" that
will protect things (like fingers) from touching the hot iron are
a very good idea. Many also have provision for a wet sponge to wipe
off the hot iron -- also very useful.
A word of caution, though: try to set up some way to assure that
the soldering iron gets turned off when you're through using it.
A power strip with an indicator light is now what I use, though for
about three decades I kept the power cord for the soldering iron marked
near the plug so that I could easily identify it, and then was in the
habit of whenever I was in that room I'd visually verify that that
plug was not plugged in. (Remember that the soldering iron is easily
hot enough to catch things on fire!)
For heavier duty soldering, a soldering gun may be required. If you
find you need one, I'd tend to go check at a True Value or Ace hardware
store.
Also check out my comments on soldering on the
Tips page.
It is an unfortunate reality that we all need to desolder stuff
from time to time, either because of mistakes, parts failing, or to
get some parts to re-use.
There are many ways to desolder parts. The expensive way is to go
with a special iron that has a vacuum system -- you use the iron to
heat the solder up to its melting point, and then there's a foot switch
to activate the vacuum. I've used them, they work well, but I really
don't think that the average electronics hobbyist can justify the
expense. (I can't justify the cost for one for myself.)
Another system uses a device called a "solder sucker" that
is sort of an overgrown spring loaded syringe: you push in the plunger,
and it catches on the latch. You use your soldering iron (or gun) to
heat up the connection and melt the solder, then move in with the
solder sucker's tip and push the trigger, releaseing the plunger to
generate a momentary burst of vacuum. These work fairly well, and
many folks get skilled in holding it in one hand and being able to
shove the plunger against their thigh to reset it.
A third option is desoldering braid. It's a thin braided tape made of
very fine copper wire, impregnated with flux. You lay the braid over
the joint to be desoldered, and then heat the braid (and the joint)
with your soldering iron (or gun), causing the solder to melt.
Capillary action causes the braid to absorb the solder. Unfortunately
there are some brands of this stuff that are rather poor and tend to
leave a lot of residue on the joint. (The stuff from Radio Shack is
amongst these.) The good stuff doesn't leave much residue, and when
you think about the effort required to clean up after it, the good
stuff is well worth the cost. The good stuff, at least, comes in
several different widths, and at least two sizes of spool (though the
large spools can be hard to find). One word of caution, though, is
to trim off the used portion when you get more than about half an
inch from the end, so that you aren't reheating the used portion.
This stuff dissipates heat very rapidly, so is very difficult to
use with an undersized soldering iron.
Also called "diagonal cutters" and sometimes by the slang
term "dikes".
As long as you don't use them to cut hardened steel wire ("piano"
wire and spring wire are examples), a good pair can last decades.
I finally had to replace mine after about 35 years of service, as the
old ones were just plain getting worn out. (My ex-wife's abusing them
by using them to cut hardened steel wire nearly 20 years ago didn't help.)
I paid around $35 for the new pair. Sure, I could have gotten a pair
for a tenth of that price, but then I'd have to replace them again in
a couple of years.
One thing to look for is "flush cutting" ones. This means
that the "back side" of the blade is flat. In operation, they
can be used right up against a surface, and more importantly, they don't
put any unwanted pressure on the piece of wire being left. As a side
light (which some may consider "too much information") I also
use mine to trim my nails. I find they work better than nail trimmers,
especially on my toe nails.
This simple tool is one that I found out long ago is an essential.
When I took a year off from college to go work in an electronics
factory, I found it indispensible to have a magnifying glass in
my pocket at all times. It makes reading the markings on components
a lot easier, as well as looking for
bad solder joints.
Although you can spend amazing amounts on a magnifying glass, you
should be able to find one at the corner drug store or office supply
store for less than lunch at a fast food joint. A word of caution,
though, is that fresnel lenses (the "flat" ones that have
concentric circles) tend to not be as good for electronics use as
just plain glass ones. If you want to have one to keep in your
pocket, there are good ones that "slide closed" for less
that you would pay for supper at Denny's. These are available in
3x and 5x, though the latter may be a bit harder to find.
A somewhat more expensive variation is an adjutable arm that
(usually) clamps onto the edge of a desk or table, and also has a
"ring" lamp around a magnifying glass. They can be
worthwhile if you're doing a lot of close work. They can often
be bought at office supply stores.
If you are the sort that doesn't lose your tools,
and you are not one to abuse your tools,
then getting a set of good screwdrivers is a good
investment.
Using scredrivers as prybars, though, is generally a form of abuse.
You can get screwdrivers that have an arrangement of
"reversible pieces" that will give you a selection of two
slotted drivers and two Phillips drivers. Some of them will
even accept other "standard" (1/4 inch) driver bits, which can
come in handy. These make an excellent addition to a tool box
that's going out "in the field".
When I first got into electronics, these were hard to find tools,
and expensive.
Fortunately, today they're relatively inexpensive and easy to
find. I like to have a large set of them, that includes both
flat-blade and Phillips, as well as small hex and nut drivers,
for the "bench". They're really useful in dealing with
those tiny screws that tend to be around many electronic devices
these days.
These are usually just a shaft with a scredriver at one end, and bent
at a 90° angle to be able to reach into tight places. There
are several variations on this idea, such as a Phillips on one end
and a flat blade on the other, or flat blades on both ends with one
parallel to the handle and the other at a right angle to the handle
(you can flip it back and forth in really tight places). These are
tools that you don't often need, and can often substitute using a
screwdriver bit in a quarter inch wrench, so my suggestion is to
put off buying one until you really need it.
One little "gotcha" that many folks aren't aware of is that
there are two types of "cross point" screws (and mating
screwdrivers). One is called Phillips, and the other is called
Reed & Prince. The way to tell the difference when looking
at the screwdriver is that a true Phillips driver has a blunt point
that looks like it was cut off. A Reed & Prince driver has a
sharp point. If you look into the screw head, you'll notice that
a Phillips screw doesn't have room for the point, while a
Reed & Prince screw dies have room for the point. The upshot
of all this is that a Phillips driver will sometimes work on a
Reed & Prince screw, but a Reed & Prince screwdriver will
almost never work on a Phillips screw.
When you get more into electronics, you may occasionally find that
a gadget has "tamper-proof" screws that have some sort of
bizzare head. Verious suppliers will sell you a set of assorted
"tamperers", officially called "tamper-proof"
bits, that will fit any driver that accepts the standard 1/4"
screwdriver bits.
There are a whole bunch of other types of screwdrivers these days,
but it isn't worth the space here.
One thing that is extremely handy in electonics, which few people
actually own, is a good set of nut drivers.
These look vaguely like screwdrivers, but they have a hex socket
on the end, and more critically, they have a shaft that is a hollow
tube.
This means that they can reach into tight spaces, and down over
protruding screws to get to the nuts. Very handy.
Nutdrivers can very conveniently deal with the nuts that are
on various controls (such as volume controls) and switches, and are
a lot less likely to damage either the nut or the panel than trying
to use a pair of pliers.
Most "desk-top" computer cases these days are held together
with screws that have a hex head that also has a Phillips "slot".
Over the years, I've found that the best tool to deal with these is
a nutdriver, rather than a Phillips screwdriver, which ends to slip
out of the hole more easily, or a socket wrench, which isn't as easy
to "spin" once the screw is a little loose.
There seem to be an infinite variety of pliers.
At some point, you'll need some for electronics work.
A pair of needle nose ones is good to have around, and can be
useful for a variety of uses.
Often times needle nose pliers will come with a small spring to
open them up. I find this annoying and usually remove that spring.
Many pliers have a section intended as "wire cutters".
Frankly, my experience is "only in an emergency" for using
these. They are almost always far inferior to a good pair of
diagonal cutters (see above), and will often leave the end of the
cut wire so damaged as to be nearly useless.
One tip: By wrapping a heavy rubber band around the handles,
you can use pliers as a make-shift vise to hold small parts
while soldering.
There is a major downside to using pliers to tighten or loosen
nuts or bolts: it is far too easy to damage the part. Use a
nutdriver (or wrench) instead. Using a pair of pliers to tighten
or loosen nuts or bolts constitutes "abuse of the parts".
To be honest, there are few places in electronics where you really
need to have a wrench. A nutdriver will generally do as good,
or better, a job.
However, for general use (like repairing cars, or household
maintenance), wrenches are essential. Good ones are worthwhile.
I'm still using a 1/4" drive Craftsman® SAE (inch) socket set
I bought back in about 1973.
This might be a good place to mention that if you do ANY work on
lead-acid batteries, as soon as you're done, rinse off your hands
and ALL of the tools you handled with plain tap water, then dry the
tools thoroughly with paper towels, and leave them out, preferably
in a warm dry place for any water to evaporate. Even a trace of
battery acid can damage most tools -- and if it happens just two
or three times in the same spot, it can destroy an expensive tool.
There are a great variety of these as well, ranging from the ones
you get at the drug store for doing such tasks as pulling out minor
splinters from your finger, to terifyingly long 12" models,
to ones (that technically are called something else) that you
squeeze to release rather than squeeze to hold.
Having a pair in the 4" to 6" range around can be handy in trying
to retrieve things, and they can also be used to hold parts while
soldering (and also used as heat sinks while soldering).
A pocket knife can be a very valuable tool in electronics,
especially when you have to do something "away from the bench".
With some practice, you can easily strip most types of wire other
than coax.
Stripping coax cable is a bit trickier, but it, too, can be done
with a decent knife and a good deal of practice.
In either event, I highly recommend practicing a lot on "scrap"
wire before you have to do it "for real".
It takes a while to be able to develop the "feel" for when
you've gone just far enough to make the insulation easy to pull
off without putting a nick in the underlying conductor.
More than a decade ago, I purchased my first Vitorinox®
Swiss Army knife.
After I'd had it for a few weeks, I realized that all of the
imitation Swiss Army knives I'd had over the years had been a
waste of money -- including the ones I'd gotten for free.
You can sometimes find a sale on them at either
REI or
Costco.
It is also handy to have a good set of X-acto® knives around.
They can be especially useful if you need to cut the trace on a
PC board, and are good for scraping solder residue and other
debris off small circuit boards.
I've had a set of these since the 60s, though I've replaced a lot
of blades.
There are a large variety of wire strippers available on the market.
Frankly, a lot of the inexpensive ones aren't worth the money --
you can do a better job with a good pocket knife and a lot of
practice.
However, there are ones that actually do a good job. One thing
to look for is a separate "slot" for each size of wire,
rather than one that is "adjustable".
If you're going to have to strip a lot of wires, then go for one of
the ones that is "automatic" -- you lay the wire between
the jaws, and as you squeeze the handles, it first clamps down on
both sides of the wire, then cuts through the insulation, then
pulls the insulation off the stripped end, and as you continue to
squeeze the handles further, it finally releases the wire.
But be warned: these are not inexpensive. Expect to pay in the
$30 to $40 (or more) range, and each will only do a limited number
of wire sizes.
The one inexpensive stripper I've seen that does a good job is
the one on an OK Tool company's all-in-one wirewrap tool, but
this is limited to 28 ga. wirewrap wire.
You can get a lot of different crimp-on terminals these days.
You can also get a lot of different tools to crimp them on.
If I'm trying to crimp a connector on more than about 24 ga.
wire (for instance, most RS-232 cable is 24 ga.),
I don't really trust it unless
I am using a crimping tool with "compound action".
These can either be gadgets that look a lot like a pair of
Vise Grip® pliers, or they can be ones that have a racheting
action where you squeeze the handles several times to make the
final crimp.
If I have to use "single action" crimpers on anything
bigger than a pin to go into an RS-232 (DB-9) connector,
I try to use uninsulated
connectors and then solder them on once I've crimped them on.
No, I'm not talking about bad habits.
I'm talking about those machines that hold things.
They can be very useful in holding electronics while you solder,
or while you try to probe and make measurements, or when you're
drilling and cutting for the box for the latest project.
You can find small inexpensive ones that will clamp onto the edge
of a table at a variety of places. As long as it works smoothly,
the jaws are parallel, and it doesn't have a lot of "backlash"
(that is, the handle doesn't have to be turned much to go from
"closing" to "opening" or vise-versa [pardon
the pun])
they can be sufficient for a while.
A good vise designed for electronics, though, is a worthwhile
investment in the long run. The best I've seen is called
Pan-A-Vise® and has an assortment of both "bases"
and "heads" in the product line.
The head can be rotated and tilted as desired.
The bases available include one that claps to the
table, one that can be permanently attached to a workbench with
wood screws, and one that is just a heavy broad base. (I have
the latter.)
The heads available include several small ones, and one that
can open up to around 11 inches and has slotted rubber jaws to
hold circuit boards (it can also close all the way). (Again,
I have the latter one.) By the way, if you get the heavy base,
be careful to pick it up by the base and not by the head --
they can slip apart if the adjustment screw isn't really tight.
(And people wonder why I wear steel-toe boots.)
An anti-static wrist strap is a vital piece of equipment.
There is a range of prices on them, and good ones will last longer
than the cheap ones.
However, even a cheap "disposable" one is better than
nothing.
It takes only a small amount of static electric discharge to
do permanent damage to a lot of electronic devices.
And by "small" I mean a fraction of what you can feel
even when you're paying attention to it.
An anti-static wrist strap will have a high, but not infinite,
resistance between the part of the strap that goes around your
wrist and the end that gets grounded.
It is high enough that you shouldn't be able to be electrocuted
through it (at least not with voltages you may have floating
around in your home), but it is still low enough that it will
quickly bleed off any charge built up by walking across the
carpet or petting kitty.
One thing I suggest looking for is one that has a banana plug
on the end and comes with an alligator clip that fits onto that
plug. The banana plug can be pushed into the ground terminal
of a power strip (assuming that it's a "known good ground"),
or the alligator clip can clip onto some bare metal, say in the
case of a desk-top computer, that is known to be grounded.
While we're on that subject, the instructions that come with a
lot of computers and computer boards say to "disconnect the
power cord" before working inside the computer. My problem
with doing so is that it also disconnects the ground connection.
Most power strips maintain the ground connection even when the
switch is turned off, though you might want to verify yours with
the power strip unplugged using an ohm meter.
One of the most useful tools when working on eletronics can be
the multimeter, also sometimes called a "volt-ohm meter"
or a "digital volt meter" (or simply a "DVM").
There is a truly staggering price range in these things. I've
seen them for as low as $2 (with a coupon) to well over $10,000.
There is some truth in the old saying that "you get what you
pay for", but they all have their place.
The really cheap ones aren't all that accurate, though
frankly, for most things they are good enough. And at those
prices, if you manage to destroy (or lose) it, it's not a major
loss.
They can be really handy for a lot of things, like verifying that
the battery in your remote control is dead (and thus the cause
of the thing not working), or verifying that you read the resistor
color code correctly (especially in not-so-good lighting), or that
there actually is continuity between two components in your
breadboard circuit (I learned, while in college, to check the
continuity of the jumper wires when you share them with other folks).
The meters today are a lot less expensive (even ignoring inflation)
than when I first started tinkering with electronics, and both
have better resolution and better "input impedance", or
how badly the meter will load down the circuit being tested.
One thing to be aware of: when you need to measure, accurately,
the value of a resistor below a couple of ohms, you need to use
a 4-wire setup rather than a 2-wire setup. (It's a physics
limitation.)
Meters that are actually capable of this generally start at
several hundred dollars.
(There are some other "tricks" you can use, but they,
too, are more advanced.)
Having a good flashlight around is always handy. No matter how
good the lighting on your bench, a small, directed light source
can frequently come in handy to see down in the "guts"
of a crowded gadget.
Tip: if you drop a small part on the floor, and have trouble finding
it, hold the flashlight down by the floor so that the light is
glancing across the floor. A part will often reflect the light,
and cast a long shadow, both making it easier to find the missing
part. Although it works best on a hard floor, it can work on
carpet as well.
And, of course, there's the inevitable power failure.
For over 25 years, I've kept a Mini Maglite® 2xAAA size flashlight
in my pocket most of the time. This particular size isn't much bigger
than a good pen, and has a neat trick: you can take the
"reflector" off it, and move it to the other end, and it
will serve as a small electric candle.
A flashlight from the dollar store, though, can serve well, provided
you have good batteries in it.
The basic concept of an oscilloscope is really pretty simple:
it shows you a graph of the voltage of the point the probe is
touching.
True, there's a lot more to it than that, but that's the basic
idea.
For the beginner in the electronics hobby, this can be a very big
aid in grasping what's going on in a circuit.
For the advanced hobbyist, it can be vital.
One of the main parameters of oscilloscopes is "bandwidth".
This is the highest frequency for which it will accurately show you
a picture of a sine wave.
Because of some math that's way beyond what is appropriate for
this web page, an oscilloscope will only accurately display a
square wave that has a frequency that is less than about 1/3 of
its stated bandwidth. (Thus, it takes a 'scope with at least a 15 MHz
bandwidth to look at a 5 MHz square wave.)
The big downside to an oscilloscope is the price.
New ones start at several hundred dollars, and go up to the
tens of thousands of dollars.
The good news is that the beginning hobbyist can often get by with
a fairly modest 'scope, say one with a 5MHz rating, and a used one
can often be purchased for a fairly reasonable price.
A good place to look for one is a hamfest.
A somewhat smaller downside is that it takes some practice to be
able to know what settings to use to get a good picture.
Although I could go on at some length on this topic, I'll just say
that the best teacher is practice.
In recent years, "pods" have been showing up aimed at
the hobbyist.
These plug into a computer, and using some software will provide
the same sort of picture that an oscilloscope would provide.
There are a couple of problems with them, though.
The first, and biggest, is that they typically have a fairly
low "maximum input voltage" so that they are easy to
destroy by accidentally connecting them to, say, 120VAC. (And
there is the possibility that doing that will also destroy the
computer.)
The second is more just an annoyance: sometimes there's a bit of
a lag between the event at the probe and the display on the screen.
One upside, though, is that it's easy to get a printed copy of
the display -- usually just a mouse click or two.
If you know someone who has a 'scope that they'll let you use
(even if you have to drag your "experiment" over to
their place), that may be the better alternative for the beginner.
Chances are that the owner of the 'scope will have some experience
in getting it adjusted to show what's going on with your
"gadget", and this can be a quick way to learn about
adjusting 'scopes.
There comes a time in the life of every electronics hobbyist when
they'd like to put some project into a nice looking case.
Some kit venders sell cases that are custom made for specific kits,
and there are several companies that advertise in the likes of
Nuts & Volts magazine (see the
Magazines & Books page)
that will take your design and produce either a bezel or a complete
case, or you could even go to a local machine shop and have it done.
However, these can be very expensive options.
Most hobbyists will prefer the "Do It Yourself" approach,
for the cost if for no other reason.
In this section I'll describe some of the basic tools. There are a lot
more advanced tools that you can use, but they tend to be expensive
and rather limited in their usefulness.
Although some of it may seem a little too basic for most people,
I'm assuming that you have no prior knowledge.
If you already have some knowledge, that's great, but I encourage you
to take a few moments to look over my comments anyway.
This is how you produce a simple, round hole in something.
There is a huge variety of different drill bits, and in the drills
that are used to hold and drive them. I'm only going to describe
the ones the electronics hobbyist is likely to need.
As for the drills, there are basically two options that will serve
the electronics hobbyist well. Either a small electric drill (either
cordless or corded, though I suggest looking for a variable speed one
these days), or one of the manual "egg beater" style drills
that is so named due to its resemblance to a kitchen implement -- it
basically has a handle to hold it, and a crank on the side to turn
the drill bit. If you really get into it, a drill press can be a
useful option, as it is much easier to both get the exact placement
of the hole correct, and get the hole perpendicular to the surface
that you're drilling through. The downsides to a drill press are the
cost and the sheer size of the beast.
The drill bits are the portion that actually make the hole.
There are an incredible variety of them, though many are for special
purposes that are of little use to the electronics hobbyist (for
example, bits for drilling through concrete).
The most useful ones
for the typical hobbyist are twist drills.
They are made in many different materials, but simple "high-speed
steel" is sufficient for most purposes.
Getting an assortment with a nice container for them is probably worth
the investment. Having a set that goes by 1/16 inch from 1/16 through
either 1/4 inch, or 3/8 inch, is certainly sufficient, and will cover
the majority of your needs for a long time.
The one other variety of drill bit that you are likely to encounter
a need for is called a hole saw -- and is used for making much larger
holes.
I would suggest only investing in these when the actual need for
them arises.
This screen last updated: 01-Apr-2011
Copyright © 2010, 2011 by Clark Jones