Mechanism for Drawing Circle

This video was made based on the design numbered as 1303 in volume 2, Mechanisms in modern technic, I. Artobolevski.
Angle between two sides of the blue L-shaped bar is 90 deg.
Yellow bar is always perpendicular to green bar.
Orange and green sliders are connected together by a revolution joint.
When pink crank of radius r rotates, center point of orange slider traces a circular curve of large radius R.
This avoids the need for hinges at distant or inaccessible spots.
R = ((OC.OC).r) / ((OA.OA)-(r.r))
The curve center is at point B, on the right of A.
OB = OA.(R/r)
If (OA – r) is small, R is very large.
If OA = r, the mechanism draws a straight line perpendicular to OA.
If OA is shorter than r, the curve center B is on the left of A.

« previous mechanism

next mechanism »