Sleeve Block, McCunn System

Sleeve Block, McCunn System
These instructions are based on the instructions and method from the book How to Make Sewing Patterns by Don McCunn (1977 revised edition) ISBN 0-932538-00-2. This book has been updated and may be purchased from Amazon: https://www.amazon.com/How-Make-Sewing-Patterns-second/dp/0932538215. In this tutorial, the method described there will be referred to as “the McCunn method”.

Measurements
The sleeve block, like all Seamly2D patterns is based on measuments of the intended wearer. Measurements must be recorded using the TAPE program (see Tape User Manual). The following Seamly2D measurements are required to construct a sleeve block using the McCunn method.


 * L01 arm_shoulder_tip_to_wrist_bent
 * L16 arm_shoulder_tip_to_armfold_line
 * L11 arm_upper_circ
 * D04 hand_palm_circ
 * L02 arm_shoulder_tip_to_elbow_bent

Before attempting to draft a sleeve pattern with this method, ensure that you have created and saved a measurement file (.vit) which contains values for L01, L02, L11, L16, and D04. The instructions for drafting a basic sleeve may be found on pages 71-75 in the 1977 revised edition or pages 79-82 in the 2016 second edition. In the McCunn method, the five measurements required to draft a basic sleeve are called


 * Arm Length
 * Sleeve Cap
 * Biceps
 * Palm
 * Shoulder to Elbow

Formulas
The Draw Mode of Seamly2D is used to create the formula based drawing in support of the sleeve pattern. Further instructions on creating the drawing for the simple sleeve block pattern may be found for the arm portion and the sleeve cap portion. Figure 1 presents the same information as a drawing from the book that describes the method. This picture shows the basic reference lines and other major lines used in constructing the main portion of the sleeve.

The McCunn method uses two reference lines. The Sleeve Centerline is drawn as a vertical line with length equal to the Seamly2D measurement arm_shoulder_tip_to_wrist_bent. The Biceps Line is drawn at a right angle to the Sleeve Centerline with half of the length of the Seamly2D measurement arm_upper_circ plus wearing ease extending on each side from the center. Wearing ease is defined in the book as a fixed number (1.5" in each half of the line for a total of 3"). This line is drawn at a distance of arm_shoulder_tip_to_armfold_line from the top of the Sleeve Centerline. ''One strength of using a formula based tool, such as Seamly2D to create a pattern is that the pattern may be generated based on individual measurements. The intent of this particular pattern is to be scalable from doll sized through the entire range of different sizes of potential human wearers. To facilitate the pattern created in Seamly2D in being scalable, the wearing ease will be calculated as 20% of the arm_upper_circ. For example, a person with a measurement of 15" at the bicep would have a sleeve drawn by this method with 3" wearing ease.'' The Wrist Line is drawn at a right angle to the Sleeve Centerline with half of the length of the Seamly2D measurement hand_palm_circ extending on each side from the center. This line is drawn at the wrist end of the Sleeve Centerline. By using the palm circumference instead of the wrist circumference, we will ensure that the sleeve opening is large enough for the hand to pass through. The shoulder_to_elbow Measurement would be used to place the elbow dart to shape the sleeve. Although the book describes adding a dart at the elbow, we will omit that from this tutorial because it does not add to the user's ability to learn to use the Seamly2D tools. Figure 1-V shows the same drawing as Figure 1, but shows the image as it will be presented in the Seamly2D program after you have finished the first half of the steps performed in the Draw Mode of this tutorial. The steps of the the arm portion will create this construct which will act as the basis for the arm portion of the sleeve pattern.

The lines shown in the goldenrod color will not be printed on the final pattern. The lines shown in the black color will be incorporated later during the steps in the Details Mode to form part of the printed pattern.

Figure 2 shows the special points used in the second half of the sleeve block pattern tutorial will demonstrate how to define the formula based drawing used for construction of the sleeve cap portion of the sleeve pattern.

'''PLEASE NOTE THAT THIS PAGE IN UNDER CONSTRUCTION.  You may click the sleeve cap portion''' to go to the detailed page that describes the steps used to implement the formulas.