8 Mar
2013
8 Mar
'13
3:47 p.m.
On Fri, 8 Mar 2013 feldman.r at comcast.net wrote:
It seems like it would be physically impossible to
make a flat spiral
_SLIDE_ rule (where one scale can be repositioned against another
scale). The Computer History Museum has a spiral slide rule
(http://www.computerhistory.org/collections/accession/102633252), but it
is not clear from the picture if the scales _SLIDE_ against each other.
In a spiral, the area of a segment that as one degree wide by one spiral
line to the next decreases as one goes toward the center, so a slide
would bind if you tried to turn it toward the center or would be loose
and not evenly contact the next band if you turned it away from the
center.
Quite true.
but imagine a disk with a spiral scale. Then add a CLEAR disk on top of
that and scribe a scale that consists of radial lines (logarythmically
positioned) The clear disk could be spun relative to the disk with the
spiral scale.
Similar could be done with a helix.
In an earlier post in this thread, someone said that
they had not used
their slide rule in anger. As a kid, I made something that would have
been useful if they had wanted to. I took a cheap wooden slide rule,
lightly sanded the groves, waxed the slide, and wrapped four big rubber
bands along the length, so one end was on the outer part at one end and
the other end was on the slide. Worked sort of like a cross bow or spear
gun. I could send the slider through 6 layers of corrugated card board
at about 20 feet!
hard to replace the ammo., and hence quite limited.
Howzbout putting a stop at the end of the travel, and let it fling
pencils?