AddThis

AddThis

Monday, 31 December 2012

Let's get Mathematical Part 12

Given: barrel 84 teeth, centre wheel 80 teeth, third wheel 75 teeth, second wheel (fourth wheel) 70 teeth, escape wheel 15 teeth, centre wheel pinion 12 leaves, third wheel pinion 10 leaves, second wheel pinion (fourth wheel) 10 leaves, escape wheel pinion 7 leaves. Calculate the number of turns an escape wheel pinion accomplishes during one turn of the centre wheel.

Z1•Z3•Z5
Z2•Z4•Z6

80•75•70
10•10•7

Answer: 600

Friday, 28 December 2012

Let's get Mathematical Part 11

Given: hour wheel 64 teeth, minute wheel 42 teeth, cannon pinion 16 leaves. Calculate the number of leaves of the pinion.

N1 = Z1 Z3
N2 Z2 Z4

1 = 16 x ?
12 64 x 48

1 x ?
4 x 48

1 x ?
192

192/12 = 16

Thursday, 27 December 2012

Let's get Mathematical Part 10

Given: hour wheel 48 teeth, minute wheel pinion 10 leaves, cannon pinion 12 leaves. Calculate the number of teeth of the minute wheel.

Motion work ratio is almost always 12:1

N1 = Z1 Z3
N2 Z2 Z4

1 = 10 x 12
12 48 x ?

1 x 10
4 x ?

10
120

120/4 = 30

Monday, 24 December 2012

Let's get Mathematical Part 9

Given: minute wheel 48 teeth, minute wheel pinion 12 leaves, hour wheel 36 teeth. How many leaves does the cannon pinion have?

Motion work ratio is almost always 12:1

N1 = Z1 Z3
N2 Z2 Z4

1 = 12 x ?
12 48 x 36

1 x ?
4 x 36

1 x ?
144

144/12 = 12

Friday, 21 December 2012

Let's get Mathematical Part 8

Given: centre wheel 80 teeth, third wheel 75 teeth, fourth wheel 70 teeth, escape wheel 15 teeth, third pinion 10 leaves, fourth pinion 10 leaves, escape pinion 7 leaves. Calculate the number of vibrations per hour, per second and the frequency (in Hertz) of the pocket watch.

Vh = Z1•Z3•Z5•(2Ze) = N1
Z2•Z4•Z6

Vh = 80•75•70•(2 x 15) = 18,000
10•10•7

Thursday, 20 December 2012

Let's get Mathematical Part 7

Given: barrel arbour core diameter 3mm, barrel inner diameter 9mm, mainspring thickness 0.1. Calculate the theoretical length of the mainspring.

Pi x (R²-r²)
2e

3.14 x (4.5²-1.5²)
2 x 0.1

3.14 x (20.25-2.25)
0.2

3.14 x 18
0.2

56.52
0.2

282.6 turns