Problem 2.3 Loci of Points

Problem 2.3 Loci of Points – KL is a crank of 35 mm length revolving in a clockwise direction. LM is a rod connected to the crank at the point L by turning pair and rod LM  is constrained to pass through the guide at O1 called trunnion. Draw the loci of points P and M for one revolution of the crank KL. The point P is 40 mm from L on the rod LM. Length of LM is 120 mm. Point O1 is 80 mm on the right and 30 mm below the point K.

Loci of Points Problems - Engineering Drawing
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Procedure:

Step-1 First draw a horizontal center line of sufficient length

Step-2 Mark a point K on the horizontal center line and draw a circle of radius 35 mm, which is the length of crank KL, with K as the center.

Step-3 Divide the circle into 12 divisions and give the notations L1, L2, L3 etc. as shown into the figure.

Step-4 Mark a point O1 at the distance 80 mm on the right and 30 mm below the point K. Which is a point representing the Trunnion.

Step-5 Draw lines starting from the points L1, L2, L3 etc. and passing through the point O1 of the length equal to the length of the rod LM, which is 120 mm.

Step-6 Mark the points P1, P2, P3 etc. at the distance 40 mm from L on the rod LM as shown into the figure.

Step-7 Connects the points P1, P2, P3 etc. into sequence with a medium dark smooth curve. This is the locus of the point P.

Step-8 Draw a smooth medium dark curve passing through the points M1, M2, M3 etc. as shown into the figure. This is the locus of the end point of connecting rod LM.

Step-9 Give the dimensions by any one method of dimensions and give the name of the components by leader lines wherever necessary.

Author: Vasim Machhar

An Engineering Drawing Geek. Working at Noble Group of Institutions, Junagadh as Head of Mechanical Engineering Department.