[next] [prev] [up] Date: Wed, 03 Sep 80 23:28:00 -0400 (EDT)
[next] ~~~ [up] From: Dan Hoey <Hoey@CMU-10A >
~~~ ~~~ [up] Subject: Addictiveness/Disassembly/Taxonomy/Lubrication/Spoilers

Hello. I saw the notice announcing the formation of this list a couple
months ago, and decided that it was one of those things I could forgo
-- until I got my hands on a physical cube. It was an immediate
necessity to own one. I bought an Ideal brand cube, which, I
understand, is of the species C. Americanus in spite of its "Made in
Hungary" label.

I had owned the cube less than ten minutes before a facie cover fell
off, without the aid of chemical additives. This was not very
destructive; just about any gummy material (I used gluestick) suffices
to hold it on. However, the screw head revealed by this unusual
transformation leads to a new method for disassembly. Unscrewing does
not stress the cube as does prying, and probably avoids the deleterious
side-effects observed by Greenberg (16 Aug 1453). This method is not
without its hazards, however. It is EXTREMELY easy to strip the threads
on the plastic X that holds the cube together. I have paper shims in
the two threads I stripped and they seem to suffice. Still, it is
probably better just to loosen the screw until the cube comes apart
with gentle prying.

There is at least one good reason for taking a screwdriver to the cube.
Mine had been assembled with several of the screws so tight that the
springs were completely compressed. Due to mfg inaccuracies in the
cubies, this made the cube difficult to twist. By prying each of the
facies off with a fingernail I was able to correct the tension.

Jim Saxe's cube, putatively of the same species but purchased in a
different store at 80% the price, has facies which seem impervious to
this prying even after disassembly a la Greenberg (17 Jul 2118). Jim
and I exhausted our fingernails to no avail, and careful prying with a
knife was unsuccessful. Additionally, this cube has a strong tendency
to jam, due either to its uncorrectable looseness or to its edge
cubies, which have oversized tongues with extremely sharp edges. The
differences lead us to believe that our cubes may belong to different
species in spite of their outward similarity.

I am amazed that anyone would put molybdenum disulfide on their cube.
Isn't that stuff poisonous? Graphite works well but is messy if you
overdo it. Silicone lubricant was mentioned by Zimmerman (25 Aug 0907)
-- has anyone any experience with this? Merrick Furst recommends soap.

For anyone who cubes in public, the only word for LACK of fear that
someone will F your cube is Cubemeistership. I made a mistake in taking
the cube to one session of a recent conference. The sequence
4(Borrow)4(Borrow') appeared to have an entropic effect on the cube and
a negative effect on the transfer of information.

SPOILER WARNING: I have one transform which I haven't seen here, and
which I find useful: an 8-qtw move to permute three corners of a face.
Specifically, for {fdl flu fur -> ufl rfu lfd} do <fdFUfDFu>.
Mnemonically, you move a socket back and forth between flu/fdl with the
f/F transforms, alternating with moving one of the three pointies
(cornies?) to be permuted into the socket. Why it works is a mystery to
me, but it's useful.

Another, which should be obvious but improves Landauer's (27 Aug 0128)
C7, is the cw monotwist {flu -> luf in u-face} <fDFdfDF>=<T1>.  Then
{flu fur -> luf rfu} is <T1U(T1)'u>=<fDFdfDFUfdFDfdFu> taking 16qtw
instead of 60 (assuming <M>=<i>, <m>=<I>).

All for now. -- Dan

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