I enjoy reading all the comments but apologize that
there are so many I can’t answer individually. I’m delighted that my
new videos have been so enthusiastically received, which is reflected in
the majority of the comments. The videos aren’t perfect though so below
each video I’ve compiled the comments about things I omitted or people
thought were misleading. A few comments added wonderful additional
information so I’ve included them as well.
Several people defended the use of ‘spring clips’ to join chain. I
should have said my problems with the clips are just with small 6mm and
8mm sizes I mostly use - for bike chain and larger sizes the spring clips
work fine. Two people described their technique for fitting the clips,
using long nose pliers between the clip and a pin, which helps prevent the
clip springing off.
It was also a bit misleading to say that chain ‘stretches’
with wear. It does get longer but this is due to the wear in the bushes
and pins making them a looser fit rather than the steel actually
stretching.
Several enthusiasts wrote about ’non-greasy’ bike lubricants. I hadn’t
come across them, but obviously a step forward.
Di Zolytan wrote that bike chain efficiency reduces
noticeably with small sprockets, under 16 teeth. 8 teeth is the generally
accepted minimum number of teeth for a roller chain sprocket, though I did
once get a 6 tooth sprocket working on my gravity escapement clock where I
needed large reduction ratios.
Juncus Bufonius reminded me about the ancient Romans use
of chains of bronze water buckets.
Two people wrote to say that the tiny fusee chain was
traditionally made by children working in appalling conditions!
Flurng desribes an ingenious use of chain I didn’t know
about to regulate the depth of deep sea bathyscapes. Heavy chain dangles
below the craft to weigh it down. Once the chain touches the sea bed any
further increase in depth reduce the weight of chain pulling down the
craft. This also reminded me of watching a large ship being launched. I
was down near the rudder and as the hull started to slide into the water
there was an extraordinary noise. I hadn’t noticed the hundreds of tons
of huge chain which were being dragged into water along with the hull to
act as a brake.
Flurng added this wonderful addition as well: One of the
most novel and unique implementation of chains that I've seen was on the
Wright Brothers' Wright Flyer craft - on that aircraft, the twin
propellers were driven from the same pulley, yet the two blades were
counter-rotatating (one clockwise, one counter-clockwise). They achieved
this by criss-crossing the left propeller drive chain, so that it moved in
a "figure 8" manner. The design included "guide tubes"
for the chain, to prevent it from snagging on itself as it crossed over in
the mid-point! Truly ingenious!
I should of course have included chainsaw chain,
particularly the difficulty of keeping the teeth sharp. I don’t often
use my chainsaw and have never found a good solution so I just keep a few
new spare chains. My friend Andy who uses them more often swears by an
angle grinder with a 3mm cutting disc, just touching each tooth gently.
Its hard to know where to draw the line, the video could easily have
been twice as long. I’m particularly obsessed by jewellry chain making
machines. A bit like hand sewing machines, a roll of thin wire goes in one
end and perfectly formed chain comes out the other. A friend has one which
I find endlessly fascinating and beautiful to watch.
