Thanks for visiting my vintage Hamilton watch blog. I like to restore US-made Hamilton wrist watches back to their original glory and share my experiences with other enthusiasts. Use the "Search" space below if you know what model you're looking for. Feel free to leave polite comments or questions in the spaces provided. Also check out my "watches for sale" on my Etsy site - the link is on the right, just below.

Monday, August 28, 2017

1960 Automatic K-475

What do you get when you cross a Hamilton 662 movement with a Hamilton 667 movement?  A Hamilton 690 movement... go figure.

For a lot of people, a major "grail" of their collection would be a 1960 Hamilton Automatic K-475.   In fact, as far as Hamilton watches go, it's one of the few models that is worth more today in inflation-adjusted dollars than it retailed for when it was new!  It was produced for only two years, 60 and 61.  They can be found for sale but they are very pricey.

The K-475 is one of two Asymmetric models with automatic movements.  It has a very unique case with swooping lugs with a texture that is echoed by the black and gold dial.  The K-475 is also unique because it is the last of three K-series models with a calendar complication.  It also has the crown at about the 4.5 hour position, which is very similar to some of the popular Electric models.

The K-475 came in a 10K yellow gold filled case and it wasn't a terribly expensive model when it was offered.  In today's inflation adjusted dollars the $100 retail price equates to about $830 in 2017 currency.  However, you would be lucky to find a decent K-475 for under $4,500 today... if not considerably more.

Needless to say, the likelihood of me finding a K-475 at a yard sale is pretty low.  So I have had to resign myself to the fact that I would never see a K-475 in the flesh.  However, I recently had another collector ask me if I would take his on.  After some back and forth, I somewhat reluctantly agreed to take it on.  You see, the K-475 is the only model to use the 690 movement.  It's a one-of-a-kind, sort of... as you'll see below.

My project watch arrived in what can only be described as in "almost new" condition.  Sure, it's been worn but it really looks solid.  The dial is near perfect - although the original luminous paint on the dial and hands has faded.

The case is a one-piece design - that's also unique among the K-series automatics.

In order to open the watch I will need to remove the crystal.

At this point there are beads of sweat on my forehead.  The 690 movement is much thicker than the ETA movements used in the Accumatic line.  Separating the two piece stem can be done by either levering the crown out and forcing the joint to separate or trying to blindly pivot the movement out without damaging the stem.

Success... it turns out the entire stem just slid out.  The set lever must not have been very tight.  Now you can see that the back of the 690 looks just like the 667 movement used in the other K-series models in the 1960's.  The rotor has a wide chamfer on the outside where a 661 rotor is more flat.

I don't really know what to expect inside the movement so I will continue the disassembly in my camera light tent.  That way if anything accidentally happens I won't lose any hard to replace parts.  They will be easy to find in the white background of my enclosure.

The back of the watch is very familiar.  The first thing to come off is the oscillating weight.  Now it looks like a 661 movement.

The dial feet screws go in on an angle - that's different.

With the dial removed, I can see the dial-side of the main plate is just like a 662 movement like used in the earlier Hamilton K-576 Calendar.   Thanks goodness... I've seen this sort of complication before.

In fact, if you look at the Hamilton Parts Manual, the 690 shares a lot of parts with the 658, 661, 665, 667, etc. but it shares pretty much all of the parts with the 662; including a unique cannon pinion and sweep second wheel.

Finding a donor 690 movement would be extremely hard - only one model uses it... this one.  But finding a 662 is almost as hard; only two models used it... the K-575 and K-576.  As fate would have it, I recently picked up a K-576 project watch with the 662 movement.  Let's call that "plan B" in case anything happens to my project K-475.

Continuing my disassembly, the first part off the front of the movement is the hour wheel - that's a unique part too, it has a gear underneath it to engage the date complication wheels.

The cover comes off next.  Three screws need to be removed.  You can see there's a spring under it that pushes on the index lever that centers the date wheel.

Now I can start to remove the various parts for the date complication.

Since there's nothing holding the date wheel in place, it can be lifted straight up and off.

Two screws hold the date advancing wheels in place.  The one with multiple grooves is reverse threaded so instead of "lefty loosey" it's "righty loosey".

The minute wheel and setting wheel come off and the movement is ready to be flipped over.

Now the movement looks like your garden variety 661 movement.  If you've followed my past projects you've seen this dozens of times.

Phew!  With almost all the parts safely removed I can go back to my regular work bench to complete the disassembly process.

Everything gets cleaned and dried.

Reassembly is pretty straightforward... I just start with the back and work my way to the front.

In order to reinstall the balance I need to reinstall the balance jewels.  That's always fun - they are tiny and easily lost.

Two sets of jewels need to go on both sides of the balance and they're held in place by shock springs.

Here's a picture of the main plate with the jewels installed.

I'd say there's nothing to complain about with this watch's performance.  It might slow down a smidgen as it breaks back in though.

I can put the automatic framework back onto the train bridge.  Three screws will hold it in place.

The oscillating weight can be installed next.

It's back to the light tent to reinstall the parts on the front.  I'm not taking any chances.

Positioning the cover on the front is easy once I push the spring over so it's up against the index lever and not on top of it, as shown.

There - I'm ready to put the dial and hands back on.

The crystal that came with the watch is in good shape but there is something adhered to the inside of the crystal that I cannot remove.  Since the dial is black, it's very easy to spot the imperfection and it's a tiny distraction.  I can eliminate it by replacing the crystal with a fresh 30.6mm PHD crystal.  A new crystal is an easy way to make a watch look much better.

Darn...  I let the watch run a while and it was about 5 minutes slow over 12 hours.  The watch looks perfect on the timer so that tells me the "almost one of a kind" cannon pinion is too loose.  It needs to be "just right"... not too tight and not too loose.  I'll have to take the dial off again and remove the cannon pinion so I can tighten it with my staking set or I can try the cannon pinion from my project K576.

Tightening a cannon pinion with a staking set is accomplished by placing the cannon pinion in a little guillotine-like stake and whacking it with a bladed punch.  A couple of light whacks with a small hammer will dimple the side of the pinion and tighten it.  That's the plan, anyway... what could go wrong?

Of course, the trick is to not dimple it too much.  So I pass a round broach through the pinion until it's barely loose.  Then at least I know I won't crush it.  You can see there's already a dimple in the side of the pinion and I'll use this as my target.  This is the sort of operation where three or four light attempts is better than one hard whack.

Here's a close up of the cannon pinion when it's reinstalled.  It needs to be loose enough that I can set the time without stopping or jarring the train wheels.  If it's too loose, the center wheel will slip inside the pinion and the watch will appear to run slow even though the watch is keeping perfect time.  I can test the fit by trying to set the time.  It should feel slightly tighter than before but not too tight.

Well, I made it!  The watch is back together and running as great as it looks.  It's hard to take a good photo of a black-dialed watch so I resorted to a slightly angled shot.  This watch looks awesome and would be the pride of any collection... any collection but mine that is.  Unfortunately this watch is headed back home to it's owner.

Of course, the good news is I don't have to sacrifice my 662 project watch and I can restore it instead.  Those are arguably as rare as the K-475... too bad they're not as sought after.

Sunday, August 20, 2017

1975 Auto Date Chadwick

Sometimes it takes me a little while to work up the nerve to tackle a watch.  For example, I have had a chronograph sitting on my bench for over a year waiting for me to take it apart and see if I can put it back together again.  It's not a complete watch and it isn't working so it's really just for my own personal edification.  Even though I have nothing to lose, it's still a daunting challenge to undertake.

Another watch that has been patiently waiting it's turn at the spa is a 1975 Auto Date Chadwick.  I've had this watch sitting on my bench looking at me for at least seven months.  I know it's going to be a challenge because it's a day & date self winding model and that means there are a lot of extra parts inside to handle.
The Auto Date Chadwick was produced for at least three years.  It's big and chunky and came in yellow gold electroplate or stainless steel.  The model number is 826017 and -4 at the end is the yellow version and -3 is the stainless steel version.

Regardless of version, tucked inside is a 17 jewel Hamilton 826 movement which is based on an ETA 2798 calibre.

My project watch is in fair condition.  The crystal has some scratches and the case has obviously seen some use but the only significant sign of wear is the crown is worn smooth on the outer surface.  I haven't detailed an 826 movement on the blog yet so I took a lot of pictures.  I'll put this post in the "Overhaul Examples" link on the right side of the screen along with all of the other movements I've tackled.  The detailed pictures will also help me figure out how to put the movement back together again once it's been cleaned.

The stainless steel back design is a new style for me.  Four large screws secure it to the electroplated bezel.

It's hard to get the camera to pick up the engraving on the back but it says Hamilton and the model number.  It might become more legible once I buff the case and get rid of the myriad scratches.

With the back out of the way, the movement appears to be held inside a movement ring that is sandwiched between the case back and the front bezel.  It's frozen solid so I'll have to think about how to get it out without damaging something.  First I'll apply a little penetrating oil to the seam and see if that frees things up.

There's a large o-ring inside the back to keep the movement sealed from the elements.  I don't see any service marks inside.  I wonder if I'm the first person to overhaul this movement in the last 40+ years?  Sure looks like it based on what I've seen so far.

A tap-tap here and a tap-tap there.  Eventually I work the movement ring out.  Turns out pushing on the crystal from the front helped to push the assembled works out the back.

According to the catalog the crystal is high tempered something... is it glass or plastic.  Looks pretty plastic to me so I'll try buffing it and if the scratches come out then it's plastic.  You can't buff out scratches from glass.

Two case screws held the movement to the movement ring.  As you can see, this is a three-piece case... a front, a back, and a middle sandwiched in between the front and back.

With the dial out of the way you can see the business end of the day and date complication.  It takes two weeks for the middle day ring to make a full rotation.  The day wheel is sitting on top of a ring that centers it on the main plate.  The hour wheel is under that ring so when I lift up the golden hour wheel in the center, the day wheel will lift off with it.

This is starting to look familiar.... most of the calendar models  have a similar setup but the extra parts needed to make the day wheel move are located on the right side.  I'll start pulling off parts one by one until I can get the date wheel to lift off.

First off is the little starfish-looking wheel between 2 and 3 on date ring (above).  This wheel advances the day when the quick-set mode is activated during setting.

Next off is the index lever up by the 11 & 12.  This lever centers the day in the day window of the dial.  There's a little spring held in place next to it.  That comes off next.

The spring is removed by pulling one of the two set bridge screws.  Removing the other set bridge screw will provide access to the rest of the setting parts.

Now's a good time to take a shot of the parts and the screws I've removed so far, in case I get them mixed up.

 Half way there... now I can lift off the date ring.

In order to get the cannon pinion off I will need to remove the parts on the left side of the movement.

I go into my light tent to take the other parts off.  There's a spring inside that is know to fly off and it's good to keep the possibility of it being lost to a minimum by enclosing this part of the effort in a 3 foot by 3 foot white tent.

With all the parts off the front I can now work on the back.  The movement is very similar in design to Hamilton's modern movements.  The main difference is most modern Hamiltons have a higher beat rate - but the construction of the movements are very similar.  One screw holds the oscillating weight onto the framework beneath.

Two blue-colored screws hold the framework to the movement.

The movement at this point looks like a typical manual-winding ETA movement.  I'll make sure the mainspring is released and then pull the barrel bridge to get access to the barrel underneath.

Now I can pull the two screws that hold the train bridge in place.  That provides access to the four train wheels and I can remove them next.

Before I take off the balance assembly, I'll open the shock spring and remove the balance jewels inside.

I close the spring and now I can pull the balance bridge and balance off.

The pallet fork is removed and now the main plate is almost free of parts.

I flipped the movement over and removed the balance jewels from the other side.  Now the movement can go into the cleaner.

Man there are a lot of parts to this watch!  Everything is cleaned and dried.

Putting the movement back together is almost the opposite of taking it apart.  In the shot below, the basic movement is back to running condition and ticking away with a brisk motion.  This movement has a 21,600 beat per hour beat rate - considerably faster than the 18,000 BPH rate that most vintage watches have.

Running a little fast but I can fine tune everything with some minor tweaking.

How's that for right on the money?

Turning my attention to the front of the movement, the only really tricky part of reassembly is to position the day wheel so that it will index properly.  First is to put the hour wheel in place and next is to line up two little detents on the silver day wheel ring with corresponding holes on the main plate.  That centers the ring and the ring centers the day wheel.  I will stick a small screwdriver near the 23 number to move the index lever out so the day wheel seats properly.

Two spacers go onto the outer circumference of the main plate and keep the dial from rubbing the date ring.

Before I put the dial back on I need to make sure I put the dial washer on top of the day wheel.  That will help the dial keep the day wheel pushed down against the main plate.

Now the dial can go back on the dial feet secured by pushing the two spring levers in to hold the dial feet tight.

I advanced the time until the day and date changed, then installed the hands at 12:00 - indicating midnight.  Notice how the dial has a ghosted mark of the chapter ring that goes on top of it.

The movement goes into the movement ring and the chapter ring goes on top of the dial.  There's no six marker on the chapter ring so that makes it easy to know what side goes where.

The two case screws secure the movement to the movement ring and the assembly can go back into the case.

The outside of the crown is well worn.  You can see it has an H logo but the crown looks like crap compared to the rest of the watch now.

I have another potential waterproof crown to use...

... but it won't fit onto the stem tube.  Changing crowns is a surprisingly complicated challenge.  There are a lot of dimensions and attributes to consider.

One of the dimensions is the outer diameter of the crown.  The original is 4.5mm.

I'll use a 4.5mm generic waterproof crown with a 2mm tube opening and a tap 10 thread.

With a huge sigh of relief I install a 20mm strap and take the completed watch to the light tent for it's pillow shot.  I have to admit that this watch really turned out great.  It was not as easy as the details above might make it out to be.  In fact, when I cleaned the dial the finish on the dial turned an opaque milky white... Argh!  I think it may have had something to do with the penetrating oil I used at the start.  It took some doing but I was able to remove the milky appearance and I treated the dial to a light application of lacquer.  It was a miraculous recovery.

It's a pretty sharp-looking watch, which is saying something for a 1975 model.  That said, I don't think I'm terribly excited by the prospect of doing another day and date model.  Fortunately they were introduced in the 1970's so my focus on pre-1969 models will keep me free of these beasts for a while.

The new crown doesn't have an H logo but otherwise it's a perfect fit.