1963 Thin-o-matic T-506

Thin-o-matics were made throughout the 1960s, starting in 1959 and well into the 1970s.  You can find them in all case materials from solid 18K to stainless steel.  Most models have micro-rotor movements made by Buren but quite a few have conventional rotor movements made by ETA.

One of the many micro-rotor models is the Thin-o-matic T-506.  It was introduced in 1963 and made through 1965.  You could buy it on a strap or on a matching stainless steel bracelet.

If you look closely at the catalog depiction you might think the dial is silver colored like the T-502.  Instead, what you're looking at it the artist's depiction of the textured pattern on the dial and it's more of a parchment color in real life.

I recently received a T-506 in need of a bit of TLC.  It definitely needs a fresh crystal and at some point the wrong second hand was installed.  First off, the second hand is yellow and doesn't go well with a stainless steel case.  Second, it's too short.

You can tell by the flat case back that this Thin-o-matic model has a micro-rotor movement inside.  An ETA-enabled Thin-o-matic would have a shallow pie-pan shape.

Inside is a 17 jewel 620 movement.  All of the parts are on one plane and the power generated by the swinging rotor is transmitted all the way through to the balance wheel through a series of interlocking wheels.

At some point the rotor was rubbing the inside of the case back.  I'll have to make sure to set it close to the movement so that it would rub.

Everything is clean, dried, and ready to be reassembled.

Piece by piece the movement is reassembled.  The only thing left to go on the back is the rotor but the watch is now ticking away with a good motion.

Based on the timer this watch is looking good.  It will slow down slightly as everything settles back into place.

I didn't have a new silver second hand but I did happen to have a black one and it goes with stainless steel much better than yellow.  It's also the correct length and extends all the way to the minute marks.  Plus it also goes great with the black croc strap.

1972 Dateline 930172

I recently came across a model that I hadn't seen before but once I became aware of it I started to see it more frequently.  It's funny how that happens.

It's a model from 1972, which is easy to identify by the model number on the case back.  Whether it's a non-cataloged US model or a model for a non-US market isn't entirely clear.  It's definitely a legitimate model though.

The model is probably a member of the Dateline family, since it has a calendar complication.  It's a manual wind watch though, and not an automatic.  It has a 10K gold filled case as well.  So maybe it's a Dateline S-4 something.  Since it's not cataloged, it can really only be identified by the numbers on the back - 970172.  The last two digits are the year the watch was introduced.

As you can see in the shot below, the watch is an interesting design.  The bezel opening looks a little like a wide-format TV.  The red second hand is original, it's been a feature on every example I've come across and I've seen about five in the last two months.  As you can see by the size relative to my thumb nail, this is a smallish watch.  However the lug spacing is a general 3/4" or 19mm so it's not a ladies model.

It takes a small moment to fit inside such an oblong watch case.  The number inside the case back is unique to this specific example.

The number on the back is the model number.

Here's a movement I haven't seen before.  It's a caliber 771.

Without the dial blocking the view, the main plate looks identical to the ladies 1971 Dateline LA-5600 that I restored in June this year.  However that was an automatic and this is it's manual winding equivalent.  I learned some important lessons about hidden springs on the LA-5600 so I'll be extra careful on this watch.

So far so good - all the parts are stripped from the front.

Looking at the back, the watch looks like a miniature version of the 688 movement.  This is obviously an ETA movement, although there are no ETA markings visible yet.

Normally the movement is marked by ETA on the main plate under the balance but that's not the case here.  In fact it's stamped 771 again, just like on the train bridge.

The acrylic crystal on the watch has a small crack so I will replace it with a new one.

Everything is clean and readied for reassembly.

The movement is running with good motion.  I noticed something unusual about this watch that I've never seen before on an ETA movement.  The hairspring coils counter clockwise so the hairspring stud and the regulator are opposite of where they typically are.

This watch has a slightly faster beat rate at 21,600 beats per hour.  It's running a little fast but I can fix that.

It took me a little while to tune the watch in because I didn't realize the hairspring stud and the regulator were swapped.  I kept moving the one when I meant to move the other and every time I did something I got an odd result.  I thought I stepped into the twilight zone until I realized my error.

Now the timing is right on the money.

In order to put the tiny spring-loaded parts onto the front of the watch I will move everything into my light tent.  Then if something disappears I will at least know its somewhere inside the tent.

Phew!  Now I just need to put one last bridge one and I can reinstall the dial and hands.

This little watch turned out really nicely.  I reapplied the brush finish to the front of the bezel, although the rest is polished bright.  The new crystal really makes the watch look great.

1955 Pelham

It's been a while since I've done a one-year wonder.  There aren't that many of them, I suppose.  Plus, I've done most of the more common models by now.

So I was happy to recently land a 1955 Pelham.  It's not the first one I've had but I realized I never put one on the blog.

The Pelham is not a particularly unique looking watch.  I guess that's one reason why it was a one-year wonder and only produced in 1955.  It kind of looks like lots of other 1950's models.  It came in a 10K yellow gold filled case and featured solid 18K gold numerals and markers on a sterling silver dial.

Since the Pelham was produced in 1955 and the same year the "new" 12/0 sized 770 movement was introduced, the catalog makes no mention of the movement inside the watch.  Early examples will have the 19 jewel 753 movement and later probably will have a 22 jewel 770 movement.

 My project watch is a decent example and my only observation is the crystal is cracked.  Other than that, it looks great.

The gold filled case back has a small amount of pitting but otherwise it's unremarkable.

Without the bezel and crystal blocking the view you can see the two-tone dial appears to be original and looks great.  I'll remove the dust and whatnot, while the movement is in the ultrasonic.

This example has the 19 jewel 753 movement.  It shares most parts with the 770 movement but it's not shock jeweled and it's missing three cap jewels.

Everything is taken apart and thoroughly cleaned.

A new glass cylinder crystal will be a nice improvement. Glass crystals are held in place with UV glue so I will install it in the bezel and put it in sunshine while I reassemble the movement.

Okay - the balance is ticking away with good motion.  Now it's off to the timer.

Well, not too bad really.  A quick tweak of the regulator will slow it down.  The beat error is within my specs but I'm torn about reducing it.  I was recently looking at some of my older posts from 2013 or older and I noticed I sometimes had beat error of 6+ ms.  My normal cut off is 3.0ms on movements where the hair spring stud is fixed but I think I'll see what I can do to reduce it further than 2.2ms.

Phew!  I didn't take photos but I should have.  In order to reduce the beat error you need to remove the balance from the balance cock, then rotate the hairspring collet on the balance staff in whatever you think the correct direction is.  It's a great opportunity to screw up the hairspring and somehow during my attempts I ended up with a hairspring that was off center.

The hairspring has to be centered or the watch's timing will be affected in one position or another... assuming it runs at all.  That meant I needed to remove the hairspring from the balance and then position the hairspring on the balance cock to see where the collect landed - then adjust the hairspring to position the collect directly over the balance jewels.  Needless to say, it's a huge challenge.

So, an hour and a half later I wound up with the following results... not too shabby.

The finished watch looks fantastic now that it has a new crystal and it runs as great as it looks.