This is a fine movement, made by H Endler of Silesia ca 1877.
Whilst told it was running when I got it, I did not attach the weights and
pendulum and see for my self. The pivot holes were very dirty and dry. The
pallet impulse faces looked nasty and there was a really horrible looking
Rathburn type bushing attached to the back plate.
These are particularly frowned upon in the horological
community. What a terrible shame that somebody did this to this fine movement.
Why?
Given no other bushing working had been done on the
movement, and given the position of the Rathburn I can only surmise that, along
with discussion with likeminded friends, that it was put there to aid assembly
of the strike train. In that the gathering pallet arbour’s position could be
adjusted post plate assemble in order to adjust the stop position of the
gathering pallet, against the rack.
It can be seen that there are 3 holes left by the Rathburn
in the plate. The smallest one was for a locating pin.
I decided to ream the largest hole, taking in the smallest
hole with it, and reaming the other on its own. The reamer has a slight taper,
allowing the use of a slightly tapered brass plug to be cold fitted/knocked in
to the plate. Given the type of movement and where the pivot hole would be in
the train i.e. quite high up, I wasn’t concerned about the friction/load of the
arbour popping the brass plug. The taper tight fit would be more than enough.
However when gathering pallets are re-fitted to the end of their arbour, they
may need a few gentle taps to home them, with a stake. This will put pressure
on any bushing on the back plate, and can pop it out. Often clock menders will
shim behind the shoulders of the arbour before re-fitting a gather pallet to
avoid such an event.
I cut a small chamfer on the inside of the plate, second pic above, to the
newly reamed larger hole. And peened into this, pic below. In the same way I would if
installing main wheel bushes on a clock plate. Excess brass was removed to original
level, and the finish restored.
The new hole for the gathering pallet arbour’s pivot
required spotting, so using a depthing gauge the spot where the new pivot hole
go should be was marked.
It was drilled using a clock plate bushing tool. The plate
could be fixed flat by the tools clamps, and the 0.72mm spade end pivot drill
held by the mini chuck. This ensured a perpendicular and accurate entry into
the spot punch mark, and ultimately a clean pivot hole.
Following the hole being smoothed, a new oil sink was cut
and this task was complete, second pic above. The plate restored to its original appearance.
A couple of bushes were required for a few other pivot
holes, however they were in generally good order. A few pivots were a little
bent, probably from previous assembly with a little heavy handedness, they were
all burnished.
It was apparent somebody had previously had an attempt at re-facing
the impulse pallets. At magnification you can see the file marks and the uneven
finish. Personally I think they were lucky the clock was running, apparently.
As described in the making of Vulliamy Pallet in another
entry on this blog, the pallets must re-faced as perfectly as possible. At the
correct angle, and polished to a mirror finish.
A small home made jig was used to fix the verge and pallets
onto the cross slide of a watchmakers lathe, ensuring that the tangent line from the brass disc (24.30mm in diameter for this verge) remains in line with the refacing surface, until the surfaces were re-faced
perfectly, using different grades of wheel. And finally polish with super fine
compound on a buff felt wheel. You can see the difference the right technique
makes.
Following a few other service related jobs and repairs the
movement was assembled and ready for testing.
Update. The movement has been on test for two weeks now and has run perfectly, so it will be going back in to its case and on the wall.
