pendulum drop

[trowel]

I have an american movt for a wall clock ,however the pend drop is
too short for my case,how can i alter the drop? Help please TROWEL

[dAz]

Post by trowel
I have an american movt for a wall clock ,however the pend drop is
too short for my case,how can i alter the drop? Help please TROWEL

clock manufactures would use a stock movement and then change the escape
wheel count to alter the beats per hour (BPH) of the movement, this is
so they could fit the pendulum length to suit the case

so to fit a longer pendulum to the movement involves changing the escape
wheel and pallets to suit.

for this you need to know the train of the existing movement so you can
work out the difference to the new train count of the longer pendulum
and how many teeth the new escape wheel will need.

you will have to remove the existing wheel and fit up a new wheel
usually means some lathe work to remount the new wheel, then fitting new
pallets, this will also involve an understanding on the escapement works
so you can adjust the drops and locks.

you can buy matched escape wheels and pallets from places like this

http://www.clock-parts.com/catalogmain2.asp?GroupID=627&Level=4

[trowel]

Thank you for your help it is a great help .I shall change it i am very capable but a bit dumb,to lenghen drop do i reduce no of teeth in scape wheel or increase.thank you Trowel

[dAz]

Post by trowel
Thank you for your help it is a great help .I shall change it i am very capable but a bit dumb,to lenghen drop do i reduce no of teeth in scape wheel or increase.thank you Trowel

less teeth, a grandfather clock with a 1 metre pendulum which beats
seconds or 3600 beats per hour would have a 30tooth escape wheel this X
the pallets would have the escape wheel rotate once per minute.

if I were to double the number of escape wheel teeth to 60 then the
escapement will now beat 7200bph or 1/2 seconds

the seconds pendulum is 993.9mm long, the 1/2seconds pendulum is
248.50mm long, so a 1/4seconds pendulum beating 14400bph would be 62mm long.

[Frank Adam]

Post by dAz

Post by trowel
Thank you for your help it is a great help .I shall change it i am very capable but a bit dumb,to lenghen drop do i reduce no of teeth in scape wheel or increase.thank you Trowel

less teeth, a grandfather clock with a 1 metre pendulum which beats
seconds or 3600 beats per hour would have a 30tooth escape wheel this X
the pallets would have the escape wheel rotate once per minute.
if I were to double the number of escape wheel teeth to 60 then the
escapement will now beat 7200bph or 1/2 seconds
the seconds pendulum is 993.9mm long, the 1/2seconds pendulum is
248.50mm long, so a 1/4seconds pendulum beating 14400bph would be 62mm long.

I think that you could cheat with this without having to muck about with the
escapement..
Have the rod made from as light a wood as possible, put the pendulum's main
weight up where it should be, and put a very light or gutted pendulum at the
bottom where it is visible. I've never tried it, but in theory, with a bit of
fiddling it should work ok, given that the difference in length is not too
much and the case allows for the wider swing angle of the lengthened rod.

[dAz]

Post by Frank Adam

Post by dAz

Post by trowel
Thank you for your help it is a great help .I shall change it i am very capable but a bit dumb,to lenghen drop do i reduce no of teeth in scape wheel or increase.thank you Trowel

less teeth, a grandfather clock with a 1 metre pendulum which beats
seconds or 3600 beats per hour would have a 30tooth escape wheel this X
the pallets would have the escape wheel rotate once per minute.
if I were to double the number of escape wheel teeth to 60 then the
escapement will now beat 7200bph or 1/2 seconds
the seconds pendulum is 993.9mm long, the 1/2seconds pendulum is
248.50mm long, so a 1/4seconds pendulum beating 14400bph would be 62mm long.

I think that you could cheat with this without having to muck about with the
escapement..
Have the rod made from as light a wood as possible, put the pendulum's main
weight up where it should be, and put a very light or gutted pendulum at the
bottom where it is visible. I've never tried it, but in theory, with a bit of
fiddling it should work ok, given that the difference in length is not too
much and the case allows for the wider swing angle of the lengthened rod.

I have had to change a couple of escape wheels on those wall clock that
have been married from odd and ends, one of my friends was telling me
about when he was in India a few years back, he was in this warehouse
where in one corner was a pile of cases, and a worker would pick a case,
walk over to the other corner and pick up a movement and put the two
together, put a dial, hands and pendulum etc, absolutely no thought in
the train count so the result was a very very slow running clock.