Читать книгу Woodcarving Illustrated Issue 77 Fall/Holiday 2016 - Группа авторов - Страница 22

Woodcarving Illustrated

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SPRING 2017

20

Finding the center of the plate using a center finder:

Draw two short lines that cross at 90°. Draw two more short lines

at 45° to the first two. If they don’t all intersect at one point (see

inset), estimate the average and mark it.

Finding the center of the

plate using a ruler:

Place the zero of the ruler on one edge while

moving the other end to find the longest distance from edge to edge.

Draw a short line at the approximate midpoint. Move the ruler so it’s

perpendicular to the first line and repeat the process. Rotate the ruler

45° and draw another set of intersecting lines.

1

Draw a baseline and a midway circle.

Draw a straight line

across the plate, through the center. Carefully measure and mark the

halfway point between the center and the edge. Use the compass

to confirm the distance. If needed, move the compass slightly along

the baseline, adjust its opening, and test again until you find an

accurate midway point. Using that setting, move the compass back to

the center and scribe a circle that passes through the midway point.

Note: You can use a thin piece of plastic to keep the compass point from

damaging the plate.

2

Divide the plate into quadrants.

Place the compass at one

point where the line crosses the circle. Open it enough to draw a

small—about 2" (25mm) long—arc approximately perpendicular to

the base line and 1" to 1-



" (25mm to 38mm) from the edge of the

plate. Swing it to the opposite edge of the plate and draw another arc.

Move the compass to the other side of the circle and repeat the process.

Draw a line through the center of the plate, connecting the intersecting

arcs.

This divides the plate into quadrants.

3

Continue subdividing the plate.

Place the compass

at any intersection of a line and the midway circle. Adjust

the compass and draw another arc midway between the

lines and about the same distance from the edge. Swing the

compass and draw another arc in the adjacent quadrant.

Continue this process three more times, creating four new

sets of intersecting arcs. Draw a straight line through the

intersecting arcs, making sure it crosses through the center

of the plate. This divides the circle into eight sections.

Repeat the process to divide the plate into 16 and then 32

sections.

Note: Resist the temptation to hurry now that you’re

familiar with the process. Slight variations in spacing can create

noticeable problems by the time you reach the end.

4

ILLUSION: LAYING OUT THE DESIGN

USE A RELIABLE COMPASS

When making repetitive arcs or circles, you must accurately

maintain the compass opening. If the opening changes at

all during a repetative step, it can affect the final product.

A small error will be compounded and the layout may not

work.

Baseline

Arcs

New line

Arcs

TIP