# RE: interference fit

```Sorry, some small error occured in the previous post.

Some formulas to calculate piston acceleration, speed and distance.
Metric system.

c = Piston speed .....................................  m/s
R = Crankshaft radius ................................  m
w = Crankshaft angular velocity ......................  rad/s
a = Piston acceleration ..............................  m/s^2
s = Distance the piston has moved from TDC ...........  m
A = Crankshaft angle relative to crankshaft at TDC ...  Degree
L = Piston rod lenght ................................  m
n = Revolutions pr. second ...........................  s^-1
S = Piston stroke ....................................  m
y = Crankshaft/pistonrod relation ....................  1

n = RPM/60
w = 2*PI*n
S = 2*R
y = R/L

c = R*w*(sin(A)+y/2*sin(2*A))
a = R*w^2*(cos(A)+y*cos(2*A))
s = R*(1-cos(A)+y/2*sin(A)^2)

aTDC = R*w^2(1+y)
aBDC = -R*w^2(1-y)

As an example, if you set R=0.1_m, L=0.2_m and w=1_rad/s.

The piston acceleration will be ZERO at approx. A=68,5 Degrees, and
piston speed will be maximum. Distance the piston has moved from
TDC => s=0.042_m

The piston acceleration will be maximum at TDC, and piston
speed will be ZERO.

--
John Torset
johnt@borre.mail.telia.com
Amiga 4000

--
John Torset
johnt@borre.mail.telia.com
Amiga 4000

```