Clock drive updates: Chain sprocket failure and ratcheting friction drive

The friction drive I devised earlier for my clock has generally proved to be somewhat unreliable.  The drive barrel ended up getting slippery, so I glued sandpaper around it to grip the drive cord.  This worked well enough to drive, but winding was then a problem.  Although you could release the friction enough to slip the cord upwards to wind, this slowly eroded the cord... and eventually the cord would break! 

Since the timer ratchet mechanism seemed to work so well, I figured that might be a good idea. But holding the friction barrel with a ratchet wasn't the first thing that jumped into mind for whatever reason, although in the end, it's what I've chosen to go with.  First, I embarked on an experiment to see whether I could use a chain drive with a ratchet mechanism.  I found some "sash chain" at the hardware store that was apparently rated for 35 lb, which is more than enough for the clock's weight of 10 lb. 

Oddly, no one seems to carry sprockets for sash chain, because it's really for window sashes, which don't actually need to be driven.  (There are sash chain pulleys, though.)  So I attempted to make my own sprocket, shown above, by cutting a barrel, drilling holes for nails and then pressing nails into the holes for teeth.  The nails were originally finishing nails that I cut to size using a cutoff wheel and a jig to ensure they were all the same size. 

Although the above picture is just an indication (don't spin with the nails installed!), I cut the barrel to a nice round circle on the lathe.  I find I'm using the lathe more and more to ensure accuracy of circles.  I find it helpful to grip a large bolt in the three-jaw chuck to use as an arbor for the work. 

Here's a picture of the mechanism in place, with a click spring and the chain installed.

Here's another picture with the clock assembled.  Notice the large gap to the left... if the winding barrel slips too far to the left, the click disengages and the weight falls! 

So, I installed a brass pipe...

... that keeps the barrel pushed to the right against the click.

Unfortunately, the mechanism was nothing but trouble.  The placement of teeth is way more critical than I imagined, and the chain kept jumping off the sprocket.  Initially, the chain would lift and jam on the gear above it, which was annoying, but not hazardous.  But as I got the teeth a little closer, the chain would jump off entirely, sending the weight falling.

So, back to the original friction drive...  Here are the parts: a ratchet, barrel, end cap, and brass pipe to keep the barrel in the right spot.

Again, I used the lathe to make perfect circles, and indeed to drill and bore all holes.

Here is the mechanism installed.  Time will tell if it proves reliable!

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.

A drive pulley for the turns

Since I had sooooo much trouble driving the turns I made, I had to think of other options.  I realized that it might work to take the idea of a super-glue arbor for the lathe, and anchor the pulley to part with super glue.

Anyhow, I turned a very small pulley from 1/4" brass rod.

Here it is attached to the part with a tiny drop of super glue, viewed under the microscope and mounted in the turns.

It's still quite difficult to operate, but seems much less troublesome.

I added an electric motor drive that seems to make it easier to use.  I guess it's now a lathe...

Making a gouge

Edwin wanted to carve some details into his pinewood derby car.  So we made a gouge for him so that he could carve by hand.

We started by turning a wooden handle on the lathe

Then we moved on to metal; we took a 1/4" steel rod and turned it down to the width he needed for his detail work.  Then, we drilled out the center

once the center was drilled, we cut a bevel for the edge.  The bevel angle was taken to match a wood chisel.

After cutting the bevel angle, I polished it with 600 grid sandpaper.

Once polished nicely, I cut the tip into a semicircle with a file.  This was kind of rough, because I knew I would get it flat with a sharpening stone.  Then we parted it off

I reversed the part in the lathe chuck and beveled so that it would self-center into the handle.

Then I ground the cutting edge flat on the sharpening stone...

... and Edwin pressed it into the handle using the lathe tailstock quill.

Door hinge turns

For doing delicate, precise work, between-centers turning on a lathe is preferable.  Generally, in the past this was done using a set called "the turns", a manual lathe of sorts.  I saw a pivot polisher setup by Charles Davis made from a door hinge, so this is my rendition of that idea.

Start by knocking the pin out from the hinge, and cut out the middle loop:

Then, I clamped the hinge on my lathe face plate and drilled holes for the locking screws:

While still secure in the lathe, I swapped out the tailstock drill chuck for a tap and threaded the hole:

The threads were checked with the thumbscrew:

Repeating on both slides and deburring results in a mostly complete turns frame.

Now for some centers... I made two from the hinge rods, since these seemed sturdy.  I started by center drilling the ends

and the tapering them.

I also filed flats on the side of each center, to ensure a stable grip for the thumbscrew.  Here two female centers are mounted in the frame:

The frame is intended to be used under magnification, and needs to be lifted to the microscope stage.  In order to mount the hinge to the top block, rather large screws are needed to not slip through the holes.  But I did not have any screws short enough to remain flush with the bottom of the block.  So I simply cut off the screw threads and made them into pegs that are hammered into the block.

Here is the completed setup under the microscope, ready for use.

Now for the bad news...  The Charles Davis setup is supposed to be powered by a squeegie blade, and is intended for clocks.  I'm intending for this to be used on watch arbors, and also didn't have a squeegie handy.  So I tried several other options, none of which worked...  For future reference, I tried:

• kite cord on a bow
• thread on a bow
• 30 gauge kynar wire on a bow
• 15 lb monofilament line on a bow
• various things with rubber bands.

In each case, I tried to drive a small balance staff directly, like the Charles Davis setup.  Most of the literature suggests using a carrier of some sort for watch arbors, which I don't have.