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The British Horological Institute Limited

Workshop Hints
Calculate Optimum Mainspring Length

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To get the best out of a mainspring, it should be the right length. If it is too long or too short, it could stop the clock or watch from running it's full length of time.With this program, you can enter the barrel and arbor diameters and the amount of mainspring that rests against the outer wall of the barrel will be displayed. There is no error checking, so make sure you enter the correct figures

Calculate amount of spring against the outer edge of the barrel
Enter Barrel Diameter: mm Arbor Diameter: mm

The optimum amount of spring against the outside wall of the barrel is mm
If your spring is a lot more than this, it is too long.
If the amount is a lot less than this the spring is too short.

 

Index of Hints and Tips

 

 

 

 

 

 

 

 

 

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