I built all the parts, assembled the clock and it
ticked along for a few seconds, I was very pleased and felt sure a
few
minor tweaks and
the job was done - I could not have been more wrong!
I soon discovered that getting a clock to run for more
than a
few seconds without stopping is the real challenge of clock making.
The gears have to be
made
extremely accurately or they
just jam up and the clock stops dead - as
you can imagine this is not an easy task especially when working
with
wood.
I ended up having to scrap and re make every single gear wheel on
this
clock and
spent many, many hours
figuring out what the problems were.
but it eventually was running pretty reliably and kept
surprisingly good
time :-)
Anyone considering having a try at making one I would highly
recommend it - its very interesting and very rewarding when you
finally
have a working clock. But don't underestimate how accurate
you
have to be with the gears and how free running every bearing has to
be
- the slightest
almost imperceptible problem with a gear tooth or bearing and the
clock
will just stop.
I have some software for designing gear wheels which I then print
out,
glue on the plywood and roughly cut out on a bandsaw. I then
have
a small vertical belt sander which I use to get the final accuracy
on
the gears. This is a time consuming task but does a pretty
good
job. If you can get access to a laser cutter I suspect this
would
be the ideal way to make the gears.
BTW - Don't forget you also need to make sure the centre hole in the
gear is very
accurate otherwise you will hit real problems - I cut the centre
hole
before gluing the template on and cutting the gears.
Before starting on making your first clock I would suggest you first
make a pair of gears, mount them on a peice of wood and whilst
putting
slight resistance on one turn the other very gently and feel for any
very slight resistance - it needs to turn reliably without the
slightest hesitation - this way you will start with a good feel for
how
accurate you need to get the gears of your clock and can avoid some
of
the
mistakes I made.
I used this clock for a good while but I have now replaced it with
clock number 2
(below).
Clock 2
This clock is completely my
own design; I watched a
flying pendulum or Ignatz clock
on YouTube and thought I just have to try making one
of these!
I
had no plans or anything more than a few pictures of these clocks,
so I
first set about
making the escapement
just to see if I could
figure it out, then when this seemed to work I started
adding the rest bit by bit until I had a finished clock - I think it
turned out
surprisingly well considering the lack of any real planning.
I had the idea in my head of how the top horizontal gears would take
the
drive towards the back of the clock but had no idea how I
could make
the bevel gears, I then had a flash of inspiration - I bought some
Mechano bevel gears from eBay and used those ;-)
It was then pretty simple working down the clock with the next 4
gears
(I
know the smaller ones are actually called pinions, but you know
what I mean)
I
then spent some time figuring out how the next part would work and
had
another flash of inspiration - If I put the drive pulley in the
centre
of the hour hand gears this would save me having to
make extra gears for the pulley.
It had now all fallen into place and I had a working clock ....
I have always said that the Ignatz clock is famously inaccurate (more
a
novelty than a
time
keeper)
and they often don't even bother fitting a minute hand
for this reason, mine was no exception. But recently I finally
got round to looking at tweaking my clock as the weight was
sometimes
striking the centre bar. I lightened the weight a little and I
have been amazed at the result, I think this had been upsetting the
time keeping far more than I had ever imagined. This clock is
now
keeping surprisingly good time :-)
This clock has been in use since Apr 09 with no major problems,
Occasionally I have to replace the string on the flying
pendulum as
it gets a bit frayed.
Although it looks pretty complicated I think this type
of clock would actually be a better first try at clock making as I
found it easier to get running reliably as the escapement of the
Ignatz
tends to keep things moving as it pulls the gears along as it swings
where as the more usual escapement tends to
stop the clock then it is up to the gears to start moving again on
their own accord.
I finished this clock in Apr 2009 and it has been in constant use
ever since, I had expected the gears to soon start wearing/breaking
especially with them being made of the cheapest plywood but so far
there are no visible signs of wear at all and it is still running
fine, in fact it is extremely rare for it to even stop. It can
keep reasonably good time when adjusted (these escapements were
never going to be very accurate) but this seems to vary a lot with
humidity changes, I keep meaning to try some different thread as I
suspect this is the cause...
I
don't have any plans for this clock as I designed it as I went
along, but if you email me I can send you the files I used to create
the gears etc..
Clock 3
I did plan to make another clock similar to clock2 but this time
use some decent quality wood and spend more time on getting a decent
finish as the one I have was more of a prototype and not great when
you
look at it close up - but I will probably never get round to it?
I have recently got interested again in playing with electronics
(something I did many years ago but never really did very well
with it),
I then discovered the
Arduino
microcontroller which makes it all so much simpler....I was never
very
good with analogue electronics with all the maths etc. but with the
Arduino this side can be kept
very simple and everything is done just by programming it in a
version of C so you can easily create some pretty impressive things
with it.
I have built myself a CNC router and this looks like the ideal tool for making gear wheels, it can cut one out
in under a minute which by hand would take me hours. If more info. on this would be of interest please let me
know as if there is enough interest I will supply details of how to build one cheaply and the easiest way to
use it.
e.g. To make a gear I draw one using Inkscape (it has a built in gear wheel tool) then use Laserweb to convert
this to the required gcode for my cnc router.
You
can contact me on - alanesq@disroot.org
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