Calculate an Estimated Mainspring

Calculator: Estimated Mainspring Number of Wheels in Drive Train: Wheel Teeth Pinion Leaves 5 Wheels Center Wheel or Center Pinion 4 Wheels 2nd Wheel Main/Barrel Wheel Expected Duration on a Full Wind Barrel Measurements 30 Hours 8 Days 30 Days Inside Diameter of the Barrel Diameter of the Barrel Arbor Results Number of Desired Turns of Barrel: Needed Mainspring Thickness: Needed Mainspring Length: Tips The mainspring width should be about .1" (2.5mm) less than the barrel depth Formulae nB = nC x WB x W2 P2 x WC or nB = nC x WB WC TMS = (2 x (DB + DA))½ - (DB + DA) x NB x (3/2) 8 LMSn = 1 x ( ( x DB2 ) - ( x DA2 ) ) 2TMSn 4 4 where, nB is the number of turns of the barrel nC is the needed number of turns of the center wheel, 30 or (8x24) or (31*24) WB is the number of teeth on the barrel wheel W2 is the number of teeth on the second wheel WC is the number of teeth on the center wheel, or center pinion for a 4 wheel train P2 is the number of leaves on the second wheel pinion DB is the inside diameter of the barrel DA is the outside diameter of the barrel arbor TMS is the mainspring thickness LMS is the mainspring length

5 Wheel Drive Train 4 Wheel Drive Train