one

two

three

four

fixed

moving

any

both fixed and moving

output and input links

input and coupler links

output and coupler links

output, input and coupler links

Structural error

Mechanical error

Graphical error

Guidance error

30, 17.5, 23.96

30, 30, 30

11, 17.5, 23.96

10, 17.5, 25

At precision points, the structural error is zero

Structural errors exist only if mechanical errors exist in synthesized mechanism

Structural errors cannot be reduced by increasing the number of precession points

The error resulting from tolerances in the length of links and bearing clearances is known as structural error

Type synthesis

Number synthesis

Dimensional synthesis

Type synthesis and Dimensional synthesis both

Dimensional synthesis

Joints synthesis:

Number synthesis

Type synthesis

${\mathrm{k}}_1\cos \left(\mathrm{\varphi }\right)-{\mathrm{k}}_2\cos \left(\mathrm{\theta }\right)+{\mathrm{k}}_3=\cos \left(\mathrm{\theta }-\mathrm{\varphi }\right)$

${\mathrm{k}}_1\cos \left(\mathrm{\varphi }\right)-{\mathrm{k}}_2\cos \left(\mathrm{\theta }\right)+{\mathrm{k}}_3=\cos \left(\mathrm{\theta }+\mathrm{\varphi }\right)$

${\mathrm{k}}_1\cos \left(\mathrm{\varphi }\right)+{\mathrm{k}}_2\cos \left(\mathrm{\theta }\right)-{\mathrm{k}}_3=\cos \left(\mathrm{\theta }+\mathrm{\varphi }\right)$

${\mathrm{k}}_1\cos \left(\mathrm{\varphi }\right)+{\mathrm{k}}_2\cos \left(\mathrm{\theta }\right)+{\mathrm{k}}_3=\cos \left(\mathrm{\theta }+\mathrm{\varphi }\right)$