TOOLS: My Olde Friends
©2008 by eddie ciletti
Did you ever have to be creative with an unfamiliar
set of tools? (Yeah, I know, sometimes this happens with "just" a software
upgrade.) Like a paintbrush, a musical instrument or recording gear, amazing
things can happen when tools become an extension of mind, body and soul.
This is made obvious on a daily basis as I watch first-time electronics
students learn to solder and use a pair of needle-nosed pliers.
Assembling a student tool kit on a budget helped
define the "essential" facet of this list. Investing in tools made from
hardened tool-grade steel alloys (plus a little respect) will ensure that
your hardware friends will have a long productive life. For example, I’ve
had a Wiha miniature screwdriver set in daily use for over 15 years that
is still very useable because its steel alloy consists of their "special
blend" of herbs, spices and in particular, chrome, vanadium, and molybdenum.
NOTE: Pure iron is too soft; iron plus carbon = one
variation of hardened steel.
TURN, TURN, CAREFULLY TURN
While your tools may be high-quality steel, the same
cannot always be said for the screws and nuts used to hold your beloved
gear together. Add to that the use of screw guns to expedite production
and you’ve got screws that often don’t want to come out on the first try.
If the driver does slip out of a screw, the head is often damaged, making
it twice as hard to get out.
One of the most important "tips" when using any screwdriver
– Phillips in particular – is choosing a driver that matches the screw
head size. The fit should be snug with no rotational "play." Before turning,
be sure to exert enough downward force to keep the driver securely mated
to the screw head.
Audio geeks need a range of screwdrivers that is
almost mind-boggling - there are easily a half dozen "standard" Phillips
and Flat head sizes alone - plus Pozidrive, security bits and the various
lengths needed for hard-to-get screws. With so many options, I’ve chosen
two multi-purpose screwdrivers that cover the four most commonly used tip
Crescent SDMB&V (under $7)
General 744DB (under $4)
FIGURE-1: The SDMB7V multi-purpose tool from
Crescent (Cooper Tools) is made from S2 grade steel. It includes #1 and
#2 Phillips, 3/16" and 9/32" flat (slotted) blades plus 1/4", 5/16" and
7/16" nut drivers. General’s pocket driver includes 1/16" and 1/8" Slotted
Tips and #1 and #00 Phillips (Cross-Point) tips.
NEEDLE ME, PLEASE
A rose by any other name – needle nose, long nose
and even chain nose – are all variants on the "electro-mechanical pliers"
theme that are rarely found at a local hardware store or even at a Radio
Shack. Notice that these are "just" pliers (not wire cutters), approximately
5-inches in length. The jaws are either minimally serrated (gripping grooves)
or not at all.
$17 ~ $20
$15 ~ $19
FIGURE-2: From left to right, entry-level
to upscale needle-nosed pliers for delicate electro-mechanical work (bending
component leads and placing parts on a circuit board).
general purpose shear cutter
$17 @ Parts Express
$16 online @ HMC Electronics
$26 @ digikey
FIGURE-3: Flush cutters are preferred over
the more common style of diagonal cutters because they leave a clean, flat
surface (rather than a sharp edge). Also note the blade diagrams: a flush
cutter ejects the lead away from the component, while a traditional diagonal
blade can inflict shock upon the component.
There are all sorts of wire and component lead cutters and while
just about anything can cut the legs off a resistor, capacitor or transistor,
it’s the "flush cutter" variant of diagonal pliers that really tickles
my fancy. No matter what’s being cut, flush cutters require less effort
and in the process, inflict minimal shock to delicate electronic components.
Flush cutters also minimize the potential for after-the-fact pain - especially
with wire ties. (Nothing is more annoying than messing with cabling with
razor-sharp wire ties, the result of using a special tool that stretches
the tie until it breaks. Faster, in this case, is not better.
The disadvantage of flush cutters is that a sharper blade is more
vulnerable, one reason it’s important to choose the correct tool for the
job. Having experience with cheap tools is motivation enough to invest
in better tools. Studer, for example, included a set of screwdrivers and
hex keys that helped establish a high standard back when I was cutting
my geek baby teeth. These days, European-made tools (like Erem) and test
equipment (like NTI) are more expensive partly because of their quality,
but also because of the poor exchange rate.
Swanstrom is a comparable US-made brand - a pair of their model 415
flush cutters is shown in Figure-3d. Manufacturers that feature "Induction
hardening" of tool grade steel results in a cutting edge hardness of 62HRc
– 65 HRc. HRx is the Rockwell Hardness Scale where "x" refers to the type
of metal under test (B for soft metals like Brass and Aluminum, C for hard
metals). HRc 55 - HRc 65 is the range typically preferred for tools and
knives. Comparable hardness for AISI (American Iron and Steel Institute)
are as follows: D2 (HRc 54), M7 (HRc 63), M42 (HRc 66).
STRIPPERS (for wire)
I confess a penchant for simple wire stripping tools over the universal
and automatic type. This is partly due to the need to understand (and teach)
the behavior of various insulation types. You might laugh, but the Jedi
approach of using "the force" will explain how some "masters" manage to
get so much from their tools with what seems like so little effort. All
of the models shown in Figure-4 sell for under $10, but prices do significantly
vary depending on the vender – higher from professional tool suppliers,
lower at DIY / hobbyist sites. Just Google the model number to find the
many tool suppliers and their varying prices.
Miller 101 / 101S
$4.75 / $6.50
Klein 1003 /1004
$6.10 / $6.80
$7 @ mouser
FIGURE-4: Simple wire strippers typically
available with or without springs. The rightmost three are made in the
US of A, believe it or not.
HEX ON U
There are so many specialized tools, but no kit would be complete
without a set of hex keys. Just as the trade name "Kleenex" has become
synonymous with facial tissue, a hex key is often referred to as an Allen
Wrench (1943, Hartford Connecticut). This tool is known by many names around
the world – Inbus (1936, Germany) and Brugola (1926, Italy). Other "keyed"
variations include Torx, Robertson (Square), Tri-wing, Torq-set, Spanner
Head and Triple Square. To my surprise, the Bondhus hex key brand is made
here in Monticello Minnesota, the company web site includes a simplified
metallurgy overview that’s worth a moment of your time.
NTI MR-2 Pro
Oscillator noise generator
VOM and dB meter
$100 on eBay
Measure dB, distortion, Phase,
FIGURE-5: From left, a) $60 sine/square
oscillator that is sold under many brand names. b) NTI MiniRator Pro, sine
/ square / noise generator features XLR and RCA outputs. c) Fluke 8060A
may be out of production but still available on the used market and great
for measuring audio levels. d) NTI MiniLyzer is an indispensable tool for
measuring level, distortion and spectral analysis to name a few.
ELECTRONIC FRIENDS (test equipment)
Test Equipment will get its own dedicated slot one of these months,
but in the meantime, here are the tools I use every day. A multimeter typically
measures Volts-Ohms-Milliamps. The Fluke 8060A (fig-5c) also measures dB
and Frequency (in the audio range). I also have several "lesser" analog
and digital meters, the latter do "other" interesting things like measure
Capacitance, Inductance and Transistor Beta (Hfe).
The cheap oscillator (Figure-5a) is great for the
price. With sine distortion below .03%, square wave function and the ability
to output +4dBm, it does most of what you’ll need at a very affordable
price. The MR-PRO (Fig-5b) is for more demanding applications that require
lower distortion (.0016), precise level control from –80dBu to +18dbdBu
and a bunch of other cool features you’ll have to go online to check out.
Similarly, the Minirator MR-1 has an article’s worth
of features, but does two things in particular that are very helpful when
working on vintage gear – the ability to measure distortion and provide
spectrum analysis. Since "distortion" measurements automatically include
"noise," it’s nice to be able to see where the noise is coming from (typically
from power supply and grounding issues). An oscilloscope is also an essential
tool, an entry level 20Mhz dual-trace scope can be had for under $300.
NEW OR USED?
All tools will suffer from normal wear and tear,
but well-made tools can be brought back to near new quality with a little
TLC (and a knowledge of sharpening and polishing techniques). I once found
a dozen high-quality used long-nose pliers like the ones shown in Figure-2
for $2 each. A little gentle grinding, filing, sanding and polishing and
they were nearly good as new.