Enter the measurements shown in metric or inches (but not mixed!)e.g. D = 50 d = 15 t = 0.45Barrel diameter (D) Arbor diameter (d) Spring thickness (t)
Mervyn Passmore's Clock Mainspring Length Calculator © M. Passmore 1980 This calculates the length using the formula described in our catalogue. Length = ((((PI x (D/2)2)-(PI x (d/2)2)))/2) /t At least 80% of the suggested length should be used.
Mervyn Passmore's Clock Mainspring Length Calculator © M. Passmore 1980
This calculates the length using the formula described in our catalogue. Length = ((((PI x (D/2)2)-(PI x (d/2)2)))/2) /t
At least 80% of the suggested length should be used.
Clock Mainspring Length Calculator © This calculates the length using the following formula: Length = ((((PI x (D/2)2)-(PI x (d/2)2)))/2) /t Repairing Your Own Clocks by Mervyn Passmore
Clock Mainspring Length Calculator ©
This calculates the length using the following formula: Length = ((((PI x (D/2)2)-(PI x (d/2)2)))/2) /t
Repairing Your Own Clocks by Mervyn Passmore