READER INPUT
Jacobean Joinery, Zinc Fumes,
Space Pods, Stealth Networks
From Makers Like You
Finally subscribed. (Me cheap, and the
cover price put me off for a while.) This community, this attitude has given me a second
technical life. I am a controls engineer looking
for something after the current career ends.
Your attitude has been a cool spring breeze.
It makes me love the basics of my science-fair
youth and believe in open-handed sharing for
the good of our common future.
I love the hell out of this MAKE thing. I’m
on board.
—Dave Weidling, Arcata, Calif.
In “Weekend Warrior Gravity Racer”
(Volume 26), author Jeremy Ashinghurst says
to “sand off the galvanized surface layer” from
EMT tubing before welding, “as it can weaken
the joint.” The reason it weakens the joint is
because burning zinc gives off hazardous
gases. The simple answer is: don’t weld galvanized steel. There are sources for thin-walled
steel tubing without using EMT conduit.
I use a TIG welder, and occasionally I can’t
avoid welding on galvanized steel. Even after
thorough grinding, the weld is never as good
as on plain steel. In addition, the torch nozzle
and tungsten get contaminated and spoil your
next weld on steel or stainless steel.
Otherwise it’s a great story — my compliments to Jeremy on an excellent cart design.
—Gord Martin, Mississauga, Ontario
The pattern for the “Fool’s Stool”
(Volume 26) repeats a common mistake:
cutting notches in the aprons (the horizontal
pieces). This creates a high likelihood of
short-grain failure (splitting along the grain).
Instead, cut a slot only in the legs, and
make it deep enough to accept the apron’s
full height.
Next, rather than gluing the joint, pin it.
Assemble the 4 base pieces and hold them
together with tape, clamps, or a helper. Now
drill two ¼" holes through each joint, one high
and one low, going from the outside edge of
the leg through the apron and at least ½"
beyond. Pound in a ¼" oak dowel and cut it
off flush (the way the author affixes the seat).
The result will be a rock-solid frame you can
expect to hold up a lifetime, if not 500 years!
This is how all the surviving boarded stools
from the 16th and 17th centuries that I’ve
examined were made.
It’s not only more authentic, it’s faster,
easier ( 4 slots to cut, not 8, and they needn’t
fit tightly because they won’t be glued), and
much stronger. See also: albionworks.com/
Stools/ STOOLS.htm.
—Tim Bray, Albion, Calif.
I teach astronomy, physics, and engineering, and I was inspired by one of my students
to think about making a device he could use
to look at the stars and planets. I hope your
readers find it an interesting challenge.
This student is good with a joystick, as he
uses one on his wheelchair. I envision an egg-shaped pod (remember the movie 2001?).
He could sit in a comfortable (heated?) chair
inside the pod away from the cool night
air and wind. We have a 40lb, 20x power,
120mm Nikon binocular telescope that could
be installed at eye level. The pod would be
mounted on a motor-driven gimbal or wheels,
controlled by the joystick, to point the student,
pod, and telescope at any astronomical object
of interest.
EDITOR’S REPLY: Good tip, Gord. MAKE’s Technical
Advisory Board agrees: welding galvanized metal creates
fumes that aren’t good for you or your weld. Further, EMT
conduit is dip-galvanized, so the zinc coating is also inside,
where it’s impractical to grind off.
12 Make: makezine.com/27
