Adjusting the escapement AKA Tweaking the "drop" and "lock"

-
The clock was running slow. Very slow. A careful review of the escapement revealed that the pallets were not aligned correctly to the escapement wheel.

Thankfully the Schatz 49 has an "eccentric" bushing that can be adjusted for just such a situation.

The "lock" is when a tooth from a wheel (brass) hits the pallet (steel). As the wheel spins clockwise the tooth should his the left side of the pallet and overlap a mm or 2. when the tooth and the pallet are touching they are engaged. They alternate left and right.

The "drop" is the gap between an unengaged tooth and a pallet.

The drop and the the lock should be about equal for both left and right pallets.

 BEFORE adjusting the eccentric bushing/screw counterclockwise 

- Entrance (left side) lock is very shallow, hitting the impulse face (with recoil), Bad.
- Exit (right side) drop large. Too wide a gap between tooth and pallet.



- Entrance drop narrow. Almost touches the tooth. Bad.
- Exit lock deep - and gets deeper. Maybe ok.

AFTER adjusting the eccentric bushing/screw counterclockwise 

- Entrance lock shallow but no longer hits impulse face. Good but maybe needs more.
- Exit drop medium/small? OK but a deep lock is better.


- Entrance drop wide/medium. A touch too far now?
- Exit lock medium (does not move much/any deeper). Probably a touch too shallow.



Locking and dropping on a 400 day escapement




























Comments

Post a Comment

Popular posts from this blog

Toothsome

-
Image
In our last episode we discussed the roughly 100 year-old Sessions York banjo clock emblazoned with Betsy Ross on its glass tablet and an eagle sitting on top.  And while in very good shape overall it was ticking and tocking in an uneven manner, what clockmakers call a "beat" problem.... What is a beat problem? Being in beat mean the clock is ticking and tocking very evenly, eg. tick-tock-tick-tock. That is a healthy beat for a clock. A tick or tock of a clock is the sound made when an escape wheel tooth hits a pallet... well... look at the gif above. You can see the escape wheel with its pointy teeth turning and gently colliding with the pallets of the pallet fork (that bent strip of grey metal). There are two pallets, one curved on top (the entrance pallet) and a second flat one on the bottom (the exit pallet).  See each one hitting a tooth? That pallet fork, also called an anchor, is attached to a crutch (the brass rod that is bent and then descends down below the image)...
Read more

Those darn teeth

-
Image
As noted in earlier episodes, your (ever learning) local horologist will often effect repairs even in the early phases of the examination of a clock. Pleasingly more of these have become regular parts of basic maintenance.   Amongst the many efforts made by this lover of brass in the early phases of examination of Charlene's Ingraham regulator clock was the quick identification and gentle straightening of an errant escape wheel tooth, hopefully preventing  the problems that can result .  Subtle, yes, but that tooth is bent forward which can upset the beat of the clock. The awake... woke... er... reader might recall a similar issue with the Sessions York banjo clock .  While the condition was visually subtle YLH did spy that bent tooth right after disassembly of the movement and while evaluating each wheel.  YLH really enjoys no longer being a clock freshman.  However, the errant tooth was not the source of the double tick / noise that was vexing this hor...
Read more

How an "ordinary" repair... wasn't

-
Image
Charlene (name changed) called a couple weeks back.  "Chip [neighbor who runs Wittpenn Antiques] gave me your name and number. I have a 'Regulator' clock that I think might be 'overwound'. Anyway it stops running after a few minutes." A few days later your local horologist headed over to Carmel for a look. Charlene was gracious and appreciative that this clock jock made house calls. And there it was in situ. A large and fine old American clock. An Ingraham timepiece (which means time only, no strike or chime; see the single winding hole on the dial just left of center).  Charlene called it a Regulator, per the glass decal, and that is mostly correct as larger timepieces like this one were considered to be pretty accurate time keepers and commonly named as such. However the term Regulator ended up getting applied to a lot of types of clocks as more of a marketing gimmick.  Spitballing YLH guessed it was made somewhere between 1890 and 1915. A couple things also...
Read more