Sunday, October 30, 2016

Balance staff (next step)

Continuing with my balance staff repairs...  I have a watch that is in pretty bad shape: no hands, no case, etc. and it has a broken balance staff.  So, I'm trying to fix it by replacing the balance staff.  The rest of the movement appears to work -- though it's very dirty.

The first step is to dismantle the balance to get at the staff...

Here is the movement without the staff.  It's a six-jeweled wristwatch.  Seems to be well-enough made, at least on the surface.  Edges are generally not filed smooth -- ok....

But surprisingly, on the back of the balance cock it appears that the drill for the cap jewel skidded across the surface!

Anyway, here's the balance assembly on its way out.

And another shot of the other side...

Here's a view of the spring collet.  It's easily removed with a screwdriver...

...and the roller table.  I also was able to pry it off with a screwdriver.

And indeed, one pivot is broken off (the bottom one in the picture above)...

After about 4 tries, I managed to turn half of a new balance staff.  It's very small:

Here is the view through the microscope.

You can see the upper pivot (appears at the bottom of the frame, and is too long) and that I've yet to turn the lower pivot. In all the watchmaking books I've found, turning balance staffs the the lathe requires flipping the staff around.  This causes lots of trouble, it seems especially since I don't have a small enough collet.  Previously, I tried a pin vice, but this is very off center when gripped in a collet.  For whatever reason, the three jaw chuck does a better job.

I was able to shorten the staff a bit (the pivots are still to large, but need polishing) using the turns/lathe I made.  Here is a view of the staff, the pulley for driving it, and a dummy for checking length.  The dummy is just a hair too short...

Ansonia "La Duchesse" initial examination

This clock is from my sister's landlady.  Here's a link to a similar model.  Inside the clock, behind the back plate is handwritten in pencil "H. Paul, June 26/85."  Presumably this means that this clock was completed on June 26, 1885.

The outside of the clock isn't in good condition.  The case is rusted, with much of the original black enamel having fallen off.

 One of the hinges has broken off, and it seems that the owner used tape to hold the glass in place as a result.

The dial surface is porcelain, which cleaned easily with dish soap and a toothbrush.

Also, it seems that the back of the bezel rusted onto the dial's gilded edge.  Rust is remarkably difficult to remove from gilding, at least without damaging the gilding...  I've removed what I could by carefully brushing with a toothbrush.

The two lions on either side of the movement appear to have been painted with a gold paint of some sort (apparently not gilding).  They were nearly black with gunk/rust.  After spending most of the afternoon in the ultrasonic cleaner, I think most of the gunk is off, but it has revealed that the gold paint is mostly gone.

The movement is missing its pendulum.  I think because the markings on the movement indicate "3 3/4", this means that the pendulum ought to be about 3.75 inches or so.  Nothing else seems amiss on the movement, though we'll see!

Here are a few other views of the movement...

Ansonia "Prism" Crystal regulator

I recently cleaned an Ansonia Crystal Regulator clock "Prism".  The clock had been sitting in my sister's landlady's basement, apparently unused for many years.  Although the markings on this clock are a bit ambiguous, it shows up in this old catalog which is dated 1905.

I made a video overview of the movement to help remind me of critical part locations.  This came in handy because I forgot to mark the striking train wheel positions, so the striking was initially off when I reassembled the movement.

The case is made of polished brass and thin glass windows.  I polished each of the brass parts after disassembly, mostly using Brasso.  However a few parts were really corroded, and needed steel wool first.  After everything was nice and shiny, I used spray lacquer to prevent oxidization.  None of the movement parts were lacquered!

I cleaned the dial (which appeared to be some kind of early plastic) with dishsoap and a toothbrush.  This seemed to do a good job on the gilded metal parts as well, but there were some places on the dial where the gilding had peeled off.  I left those alone.

I cleaned each of the four glass windows with warm soapy water, which worked very well.  Except for one thing -- the soapy water makes them slippery!  I accidentally dropped one window, which promptly shattered on my concrete floor. I spent the next few hours making a replacement window from a thin lexan sheet (32in x 44in x .093in Polycarbonate Sheet).  After cutting the lexan to size, I beveled the edges on a beltsander to match the bevel of the glass windows.  Then I polished the bevel with increasingly fine sandpaper (up to 600 grit), then steel wool, then with polishing rouge, and finally with toothpaste.  Although replacement window is pretty sharp, it isn't exactly the same as the others, so I put it in the back after reassembly.

The movement showed very little wear of any kind, and each pivot hole was still quite round.  I did take the time to polish each pivot by hand, by gripping the arbor in a pin vice and spinning the pivot in a small piece of fine sandpaper.  Since this could conceivably score the pivots, I checked each one under the microscope to verify that they were indeed mirror-polished.

Assembling and oiling the movement wasn't particularly challenging, since I had previously made a pivot locator as suggested by Mark Headrick.  Once the movement was together, it did require a bit of thought to get it back in the case.  There is very little room to maneuver once the glass windows are installed, and I didn't want to scratch or fingerprint anything.  After getting the movement inside, I realized that the intended assembly order is:
  1. Assemble the case (no side windows),
  2. Install the dial (no movement),
  3. Attach the movement to dial,
  4. Install the side windows,
  5. Install the inner top,
  6. Install the chime,
  7. Install the outer top.
The clock runs rather smoothly, and has a satisfying "gong" sound that chimes once at each half hour, and chimes the hour at the top of each hour.  After a little bit of adjustment, it seems to keep time to about one minute each week.