OPINION: Don't do TZ clock mods.

[John Hermann]

I just finished reassembling my TZ after a full dismantling of the play
field
for cleaning. I still have a problem or two; one being with the
flippers
which I will address next. The last thing I did was to dismantle the
clock for clean up and repair. After considering the famous "TZ Clock
Modifications", I decided I didn't want to deface my clock by drilling
holes in it. Rather, I came up with a different solution which needs
to be proven with time before it can be said it is better. The main
problem, of course, is the fact that the bulbs heat up the clock and
damage connections, optos, and other components. The documented bulb
to use in the clock is a #86 which is a 6.3V 200mA (or 0.2 Amp) bulb
that is suppose to have a life of 20,000 hours. With four of these
bulbs in the clock enclosure, you are dissipating approximately 5 Watts
of power. By replacing the jumpers with diodes, you effectively reduce
the power dissipated by a factor of 2 so the power is now down to 2.5
Watts.
This move alone should make a significant difference in the reliability
of
the clock. Although I have not seen a clock with the above mentioned
mods, I would expect the clock to be somewhat (but not drastically)
dimmer
with the diodes. I can understand that drilling the holes in the clock
will make it bullet proof, but also potentially ugly.

Instead of using #86 bulbs with the diodes and drilling of holes, I
simply
used #84 bulbs. These are bulbs that have the same profile as the #86,
but
only require 40 mA (or .04 Amp) per bulb! Thus the total power
dissipation
for four bulbs will be approximately 1 Watt! I noticed when I was
reassembling
the clock, that there is about a 1/8th inch gap above the back wall to
the top of the clock. I don't know if this was intentional, or if it
was added on the later version of TZ, but it should provide enough
ventilation
for 1 Watt of power dissipation. I must state that the light intensity
of the clock is considerably less now. However, I prefer the lesser
intensity
light; it gives the clock a mysterious (ghostly) feel as opposed to a
bright happy feel. Somehow that seems more appropriate for the Twilight
Zone theme. As I recall, most of the TZ TV episodes were dark in
nature.
BTW, the #84 bulbs also have a 20,000 hour life expectancy. Also, you
could
still add the diodes and reduce the power usage to 0.5 Watts, but I fear
the intensity of the light would suffer too much.

Another thing that I did to my clock to try and reduce the noise from
gear chatter was to use a lithium based grease on the gears and gear
posts. This seemed to have worked very well, as I can barely hear the
clock
running now. Before, the previous owner used a light machine oil to
excess, and it actually leaked out of the clock onto the play field.
I had to fully dismantle the clock to clean up the nasty oil and apply
the lithium (white) grease. The grease should have a tendency to stay
on
the gears and not leak out of the clock. Also, white grease is
"cleaner"
in nature than machine oil. I'm a little upset with myself for not
using
the white lithium grease on the moving parts for the gum ball machine,
but I
didn't think of it at the time. BTW, if you didn't know, the hardest
part of
dismantling a TZ play field is doing the steps for removing the gumball
machine;
what a pain.

Note: The usual disclaimers apply.

Best Regards,

John Hermann