1977 Hamilton Mantel Clock

And now for something completely different...

Although you might think watches and clocks are similar, they can actually be very different.  To my knowledge, prior to 1969 Hamilton Watch Company didn't make clocks, although the company did diversify into other industries like military time fuses, etc.

However, 1970 and beyond is a different story.  The Hamilton brand was extended to lots of different time-related products including alarm clocks, desk clocks, wall clocks and mantle clocks.  Some of the clocks used electronic movements, others used quartz movements, and still more used mechanical movements.

Over the last few years I've picked up a couple of Hamilton-branded mantel clocks with Westminster chimes.  With a little cleaning and some fresh oil, I was able to get them running,  They made nice gifts.

Recently I picked up another one on shopgoodwill.com.  In fact, there were several for sale at the same time.  It's always a risk to buy something online but it wasn't too expensive... around $40 delivered.

As received, it was not running but it looked to be in good shape otherwise and had no significant damage or blemishes.

These clocks use a Hermle movement, made in West Germany, with a whopping two jewels.  What's funny about these mantel clocks is regardless of the brand (Howard Miller, et al) they all seem to use the same Hermle movements, not to mention what looks to be the same cases and dials.  They're accurate time pieces and typically run within 30 seconds per week.

Hermle is still in business today and makes all sorts of movements including cuckoo, mantle clocks, and grandfather / grandmother clocks too.

This particular model has hammers on the bottom (as opposed to the side) that strike chime rods installed inside the case.

This specific model is called the Whitehall.  I've seen other models and they differ by the case shape, dial/hands and the wood finish but are pretty much the same inside.

Like watches, clocks need to be maintained or they will eventually stop working due to wear or  accumulated dirt.  The latter can just be cleaned but if the watch has a lot of wear, new bushings may be needed.

A lot of times you can pick out the dried oil in the pivot holes with a sharpened peg wood stick, then re-oil the train wheels.  However, that did not work with this clock.

I took out the barrels and placed the entire movement in my ultrasonic cleaner (without the balance) - twice - and it looked very clean when I was finished.  I was optimistic when it started to run but it petered out after about an hour.

Sometimes these clock can be so worn that the wheels no longer engage properly but since it ran at all, I was hoping it was just still dirty.

I decided to go all-in and take the movement completely apart and clean it like I would a watch.    I consulted a couple of YouTube videos and gave it the old college try.

The first thing you have to do is remove the hands and the dial.  That's easy to do since the dial is held on with four simple screws, one in each corner.

Then the main springs have to be let down so there's no energy left in the clock.  This clock has three mainsprings, one for the chime train, one for the strike train and the third for the time train.   I don't have a proper let down tool so I temporarily attached a wooden dowel to the winding key.

The key engages the arbors of the barrels and each barrel has a "click" that holds the barrel's energy when you wind the clock.

Holding tension on the barrel, I release the click and let the spring unwind by holding the wooden dowel while it rotates backwards.

Now I can pull the snail gear that the hour hand attaches to.  This uniquely-shaped gear is what enables the strike train to chime on the appropriate hour.

Next I place the clock dial-down and remove the 8 screws that secure the movement to the inside of the case.

This is a view of the back of the movement.  The wheels on the left side are driven by the chime train.  As the wheels rotate, they rotate a music box-like gear under the movement that raises the hammers for the chime... ding, dang, ding, dong.  The silver lever on the right side is driven by the strike train and each hour the lever raises and drops the 3rd, 4th and 5th hammers together for the gong, gong, gong sound that marks what ever the hour happens to be.

This movement has a floating balance, a very interesting mechanism with an elongated hairspring.  I'll remove the balance before any mishap damages it.  This is a two-jeweled movement and the jewels are in this assembly.  Two screws hold the balance in place and once they are removed the assembly can be carefully lifted out.

Now I'll remove the hammer assembly.  Two screws hold plates on the back side and two screws hold another plate on the front side.

The music box gear in this movement is plastic, others I've seen are metal.  The ridges move individual hammers as the gear rotates and when the ridge clears the hammer, it falls and strikes the chime rod.

Now the front plate can come off.

Many of the external parts of the movement are held on with snap rings.  In the shot below I'm removing the lever assembly for the strike train.  Just slip the snap ring off and the lever comes off.

Notice the 77 above the movement markings... that indicates that this movement was made in 1977.  In 1988 Hermle adopted letters so an A would represent 1988, B 1989, etc.  That makes identifying the age of the clock very easy.

Two of the three ratio wheels for the chime train are held on with snap rings and the third is held on with a set screw.

Now the back of the movement is free of parts.

Turning my attention to the front of the movement, I'll remove the screw that holds the keeper for the main spring ratchets.  The clicks are riveted on and won't come off.

Once the keeper is removed, I can lift the arbor straight up and out of the barrel.

With the arbor is removed, the barrel can be slid out from between the two main plates.  The chime-side mainspring is larger than the train and strike sides.  The number 41 can be used to order a replacement, if the spring happened to break.

The other two barrels are marked 40.

The strike rack can come off next.  This unique saw-toothed part is what controls the number of times the clock strikes on the hour.  It has a snap ring too.

There are a couple of springs to be mindful of when taking apart or reassembling the movement.

There's a star wheel on the minute hand shaft at the very bottom of the next photo.  A lift lever rides along the star wheel and every 15 minutes the lever is lifted to engage the chime train levers.  One of the lobes on the star wheel is larger than the other and that indicates the top of the hour.

With the strike rack out of the way I can remove the snap ring that holds the lever in place.

Now I can do the same with the levers for the strike train.

Once the snap ring is removed I need to be careful with removing the spring that is attached to the adjoining post.

There... all is well.

Next I can turn my attention to the chime side.

The chime cam is held on with two set screws.  It's a uniquely shaped part with lobes that represent the 15, 30, 45 and one hours points.  The cam rotates until the train is stopped and the length of the lobes dictates how long the chimes chime.  15 minutes is the shortest chime and it has the shortest lobe.

The shaft for the chime levers are held on with collar between the main plates.  Once I loosen the set screw the shaft can lift out.

The part that stops the chime train is also held on with two set screws.

I can remove the chime-silent lever that allows you to turn the chimes off.

Slowly the front of the main plate is stripped of parts.

The cam for the strike side is held on by friction so I will use a couple of stout screwdrivers to carefully pry the cam up and off.

Finally!  That was a lot of parts to remove but I'm not finished yet,  I still have to remove the three arms that hold the movement to the inside of the case.

I'll mark the arms for upper right, lower right, etc. so I put them back in the right place.

I take a picture of the train wheels from the side so that I can see which wheels go where.  Once I separate the plates all of these parts will come loose and fall out of place.

Here's a picture of the empty back plate.  This clock has been cleaned at least once before and some of the lacquer that protects the brass is compromised.

And here's the inside of the front plate.  The large wheel and the minute shaft won't come off, at least not easily.  The star-shaped silver wheel is actually a spring that allows you to set the time by moving the minute hand without jarring the time train.

I put the various train wheels into separate bins so they don't get mixed up.  Here are the chime train wheels.

Here are the time train wheels.  Notice one of them is the pallet fork.

Lastly, here are the strike train wheels.

All of the parts are put in a bin so I can transport them to the kitchen.

I'll use an old toothbrush and warm, soapy water to scrub every part clean of any remaining oil or grime.

All of the parts are cleaned and dried.  I carefully inspected every hole used by the three trains to make sure they were not worn oblong or in need of a bushing or two.  Everything looked good.

The goal at this point is to get all of these parts back together and not have any parts left over.  The train wheels really aren't that difficult, they only go on one way.  The larger gold wheels engage the smaller silver pinions on each shaft until ultimately the fan-bladed governor is engaged and in place.

Okay, after about an hour of fiddling, the two main plates are back together with all of the train wheels properly installed.

I will spare you the blow-by-blow details of reassembly, but eventually the movement is back together.

There are some important details to keep in mine when putting this movement back together so that it chimes properly.  I recommend you check out this YouTube video.  It provided some great instructions and explanation.

The last challenging part to be reinstalled is the music box gear and putting it in place requires knowing the correct position so that the hammers are raised in the proper sequence.  The wheel has one spot where the 1st, 2nd, 3rd, and 4th hammers are raised in sequence.  That should be the position when the chime cam is in the hour position so that the next time the clock chimes 15 minutes it chimes 1, 2, 3, 4.  It's a little tricky to get it into the right spot but you'll know it when you hear it.

The only parts of this clock that I was unable to clean were the mainsprings.  You need a special tool to remove clock mainspring, because clock mainsprings store an incredible amount of energy and can break your finger or worse if mishandled.

I enjoyed this project a lot so I've since purchased the mainspring tool shown in the YouTube video above.  That way I can complete the overhaul and ensure the trains have full energy.  I could have also just purchased three new barrels (at considerably less expense) but what's the fun in that?

The finished clock now runs as good as it looks and it's chiming every 15 minutes is an almost constant reminder of my work.  If it were up to me I'd have one of these in every room of my house, but I think my wife would discourage that idea.   I just like listening to the ticking, personally.