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Platform escapement-cylinder type


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I recently received an antique weather station (clock, thermometer, barometer) to repair.  Right off the bat I noticed the clock had a broken mainspring, the wood casing for the thermometer was broken apart and the barometer was missing all but the aneroid assembly.  

The background of the piece is unknown, as there are no markings to be found.  It was discovered in the attic of an old house during renovations by the new owner.  The customer has requested it be repaired to working order so he can hang it in the front foyer of his new home.  

Long story short, I cleaned the aneroid assembly and after patiently scouring eBay for barometer parts, I pieced it back together.  The same went for the mercury thermometer.  The clock was fairly straight forward.  I cleaned it, inspected it for wear, replaced the mainspring and it was all well and good.  All well and good except it was obvious the clock had been worked on before, or at least the platform escapement had been.  

What I noticed was that the hairspring has been replaced.  Not well either.  It was very long, as in many coils.  So much so that the entire hairspring was lobsided as it was recieving pressure from the regulating pins.  Also, the end of the hairspring ran through a hole on the balance cock and was secured I place with a tiny tapered pin.  I had never had to deal with a situation like this before.  

The piece is still in my care at the moment.  I’m waiting on a new barometer pointer hand.  And as wait I really want to address this hairspring issue.   

Can someone’s help me?  I still need to put the proper bends in the hairspring for the regulating pins, but how much coil do I need?  It’s running at minus 5 mins per day right now.  Take length out and add the bends is easier said than done.  Any advice?  

Pics to come soon.  

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2 hours ago, TimeCollector said:

 Also, the end of the hairspring ran through a hole on the balance cock and was secured I place with a tiny tapered pin

That's the correct method for securing the hairspring on these cylinder escapements, You will need to provide good pictures of the platform before anyone can give you a assessment of whats wrong and needs doing.

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When you say you have cleaned the clock have you just cleaned the pivot holes and pinions because it still looks quite dirty to me, it has had some bad bushing work done in the past judging from the photos. I would start again on the movement and give it a good clean paying particular attention to the pivot holes and pinions and checking closely for wear in the train eliminate the possibility that you are loosing power through the train.

The platform needs running through a cleaning machine, are the balance pivots in good condition ? are any of the jewels cracked ? its hard to tell from the photos . When running the hairspring should bounce freely between the curb pins.

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I've cleaned the clock a couple times to remove most of the blackish patina.  Judging by the blistering throughout the entire woodwork and the sooty build up once on the movement, I'd say it experienced some heat.  Yes, the bushings are not great but there is good freedom of movement through out the gear train.  The pivots on all gears look ok, jewels are good, escape wheel teeth good too.  However, the cylinder portion on the balance staff has noticeable wear.  

I'll give it another go and see about sorting out that hairspring coil.  Since I took the pictures I've got most the kinks out.  I'll keep working at it and see what happens once it goes back together.  

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As you take out some length of H/S, expectedly about two milimeter( to allow for active length reduction), you would need to instal the H/S  correspondingly in advanced poistion, so the fifth or escapement wheel engagement is timely and sounds in  good beat.

I woudn,t bend before timegraph, vibrograph indicates you are close to the right length and no further shortening of H/S active length is needed.

I get good bends with H/S removed and laid on flat surface, preferably white sheet of paper laid on some flat surface to keep the entire H/S level. Repeated bending would hurt the crystaline structure of H/S so weakens  H/S metalurgically at bends. 

 

Enojy the project

Regards

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Remember a cylinder escapement doesn’t have a compensated balance wheel. Depending on the conditions of the weather, it can gain or lose time. Never clean these hairsprings in a cleaning machine. I used Ronsonol lighter fluid. The cylinder is made up of three parts; the two ends are called plugs. The middle part where the escape wheel passes through, if it has worn with marks it will decrees the rotation of the balance wheel significantly, in some bad cases it will stop. Cylinders are tricky to repair/replace.  I agree with others on what they have said. The clock is called a 8 day drum and from what I can see it is French.   

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