I have an old clock (30 day windup) I want to power with a weight
that automatically raises a couple inches every 4 hours so I don't
have to wind it. The clock will run with a 8 ounce weight hung on an
arm extending about 6 inches from the drive wheel. The main drive
wheel moves about 180 degrees per day and there are 13 clicks on the
drive ratchet per revolution, so each click represents about 4 hours
and about 3 inches of distance at a radius of 6 inches. So, the
winding mechinism has to pull down 3 inches on the arm at 180 degrees
from the weight every four hours, or some combination of radius and
distance.

My idea is to construct a solonoid with a strong magnet inside that
pulls down on the arm, moves it about 3 inches and lifts the weight up
on the other side, but I'm not sure how to construct the solonoid. It
needs to be fast acting (1/2 second or less) so the clock doesn't lose
a second while power is removed. Seems like the work involved is about
3 watts for 1/2 second (1.5 wattseconds). One foot-pound per second is
about 1.5 watts, so 1/2 pound and 1/2 second should be about the same,
or maybe 3 watts for 1/2 second ignoring losses. The battery will be 2
lithium cells in series, or about 7 volts regulated down to 5. The
pendulum will also be synchronized to a small air core electromagnet
controlled by a quartz crystal oscillator for good accuracy.

So, the question is, how to construct the solonoid to do the job?How
may turns of wire, etc. to make it work? I have a few of those extra
strong magnets from disk drives I was thinking of mounting in a tube
with copper wire wound on the outside, but I don't have the details
(length, turns, etc.) without experimenting. Maybe I can buy something
ready made?

Thanks,

-Bill

Bill Bowden wrote:
> I have an old clock (30 day windup) I want to power with a weight
> that automatically raises a couple inches every 4 hours so I don't
> have to wind it. The clock will run with a 8 ounce weight hung on an
> arm extending about 6 inches from the drive wheel. The main drive
> wheel moves about 180 degrees per day and there are 13 clicks on the
> drive ratchet per revolution, so each click represents about 4 hours
> and about 3 inches of distance at a radius of 6 inches. So, the
> winding mechinism has to pull down 3 inches on the arm at 180 degrees
> from the weight every four hours, or some combination of radius and
> distance.
>
> My idea is to construct a solonoid with a strong magnet inside that
> pulls down on the arm, moves it about 3 inches and lifts the weight up
> on the other side, but I'm not sure how to construct the solonoid. It
> needs to be fast acting (1/2 second or less) so the clock doesn't lose
> a second while power is removed. Seems like the work involved is about
> 3 watts for 1/2 second (1.5 wattseconds). One foot-pound per second is
> about 1.5 watts, so 1/2 pound and 1/2 second should be about the same,
> or maybe 3 watts for 1/2 second ignoring losses. The battery will be 2
> lithium cells in series, or about 7 volts regulated down to 5. The
> pendulum will also be synchronized to a small air core electromagnet
> controlled by a quartz crystal oscillator for good accuracy.
>
> So, the question is, how to construct the solonoid to do the job?How
> may turns of wire, etc. to make it work? I have a few of those extra
> strong magnets from disk drives I was thinking of mounting in a tube
> with copper wire wound on the outside, but I don't have the details
> (length, turns, etc.) without experimenting. Maybe I can buy something
> ready made?
>
> Thanks,
>
> -Bill

A motor and cam would be easier. But not as interesting.

Ed

On Feb 24, 1:47=A0pm, ehsjr <eh...@bellatlantic.net> wrote:
> Bill Bowden wrote:
> > I have an old clock (30 day windup) I want to power with =A0a weight
> > that automatically raises a couple inches every 4 hours so I don't
> > have to wind it. The clock will run with a 8 ounce weight hung on an
> > arm extending about 6 inches from the drive wheel. The main drive
> > wheel moves about 180 degrees per day and there are 13 clicks on the
> > drive ratchet per revolution, so each click represents about 4 hours
> > and about 3 inches of distance at a radius of 6 inches. So, the
> > winding mechinism has to pull down 3 inches on the arm at 180 degrees
> > from the weight every four hours, or some combination of radius and
> > distance.
>
> > My idea is to construct a solonoid with a strong magnet inside that
> > pulls down on the arm, moves it about 3 inches and lifts the weight up
> > on the other side, but I'm not sure how to construct the solonoid. It
> > needs to be fast acting (1/2 second or less) so the clock doesn't lose
> > a second while power is removed. Seems like the work involved is about
> > 3 watts for 1/2 second (1.5 wattseconds). One foot-pound per second is
> > about 1.5 watts, so 1/2 pound and 1/2 second should be about the same,
> > or maybe 3 watts for 1/2 second ignoring losses. The battery will be 2
> > lithium cells in series, or about 7 volts regulated down to 5. The
> > pendulum will also be synchronized to a small air core electromagnet
> > controlled by a quartz crystal oscillator for good accuracy.
>
> > So, the question is, how to construct the solonoid to do the job?How
> > may turns of wire, etc. to make it work? I have a few of those extra
> > strong magnets from disk drives I was thinking of mounting in a tube
> > with copper wire wound on the outside, but I don't have the details
> > (length, turns, etc.) without experimenting. Maybe I can buy something
> > ready made?
>
> > Thanks,
>
> > -Bill
>
> A motor and cam would be easier. =A0But not as interesting.
>
> Ed- Hide quoted text -
>
> - Show quoted text -

Yes, I have a motor and some plastic gears salvaged from a toy car
that may work. I can get about a 24:1 reduction with the gears but i'm
not sure how long the motor will last turning on and off 6 times a
day. That's 180 uses per month or 2160 per year. I have a spare motor
from the other wheels, so I can probably keep it going for a few
years, but I'd rather have something that never breaks down.

-Bill

--You might want to post this to the alt.horology group. Also check
out a type of clock called a Synchronome.

--
"Steamboat Ed" Haas : Don't forget to spay and
Hacking the Trailing Edge! : neuter your politicians...
http://www.nmpproducts.com
---Decks a-wash in a sea of words---

On Feb 25, 2:19=A0am, steamer <stea...@sonic.net> wrote:
> =A0 =A0 =A0 =A0 --You might want to post this to the alt.horology group. A=
lso check
> out a type of clock called aSynchronome.
>
> --
> =A0 =A0 =A0 =A0 "Steamboat Ed" Haas =A0 =A0 =A0 =A0 : =A0Don't forget to s=
pay and =A0 =A0 =A0 =A0 =A0 =A0 =A0
> =A0 =A0 =A0 =A0 Hacking the Trailing Edge! =A0: =A0neuter your politicians=
....
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0www.nmpproducts.com
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0---Decks a-wash in a sea of words--=
-

We run the synchronome club, just goto http://www.clocktrust.com then the
club section and click on the electric clock club.