- - AGRICULTURE CORE CURRICULUM - -

(CLF2000) Advanced Core Cluster:  AGRICULTURE MECHANICS

 (CLF2350)  Unit Title:    METALWORKING

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 (CLF2354)  Topic: Layout and                   Time           Year(s)
                     Transferring on Metal      2 Hours    1 / 2 / 3 / 4
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          Topic Objectives: Upon completion of this lesson the student will 
                             be able to:

          Learning Outcome #

             (H-3) - Lay out a drawing on metal for project construction.

          Special Materials and Equipment: Graph paper, pencil, ruler,
                       compass, small sheet metal piece, scribe or scratch 
                       awl.

          References: Burke, Stanley R., & Wakeman, T. J. (1990). MODERN
                         AGRICULTURAL MECHANICS (2nd ed.). Danville, IL:
                         Interstate Publishers.
                       Phipps, Lloyd J., & Reynolds, Carl L. (1990).
                         MECHANICS IN AGRICULTURE (4th ed.). Danville, IL:
                         Interstate Publishers.

          Evaluation: Quiz by instructor and evaluation of lay outs and
                       transfers on paper, sheet metal, and metal.

TOPIC PRESENTATION: LayOut and Transfer

A. Planning - An important step in beginning any project is thinking it
   out. A drawing can assist the thought process. (Note: Review CLF 2450, 
   Project Design).

   1. Layout Tools - Both measuring and layout tools require skill in
       use and care in handling and storage. Provide clean and dry
       work areas and storage cabinets to house tools. Wipe all metal
       tools with a lightly oiled rag to protect their finish. Steel wool
       can return rusted metal tools to usable condition.

       a. A steel rule is used in making linear measurements, checking
           straight lines, and projecting straight lines onto metal.
           A steel rule's normally marked in units down to 1/32."

       b. A scribe is used to scratch the surface of metal when marking or
           projecting lines. Keep the end sharp with emery cloth.

       c. A combination square set is a very versatile tool for checking the
           project squareness, centering on a circle or pipe, and developing
           any angle down to 1 degree by using the protractor head.

       d. A spring divider is used to transfer a dimension or measurement
           from the rule to the metal. It can also be used to scratch 
           circles or arcs in the metal.

       e. An awl or a prick punch is used to transfer directly from drawing 
           to sheet metal by placing the drawing on top of the metal and then 
           tapping the awl with the palm of the hand to mark the metal 
           through the drawing.

       f. A center punch is used to enlarge a mark for a drill to follow in 
           order to prevent wandering of the drill bit.

       g. A steel pencil with soft, grey, special lead allows the 
           metalworker to mark for rough measurements to about 1/16"
           accuracy. This mark is easily seen and will work on the oil 
           coated surface of most steels.

       h. Soapstone is a white, soft, natural element cut to either a
           rectangular or round shape about 4" long and used to mark
           rough measurements on steels for rough cutting.

       i. A combination bevel is a transfer tool used to copy different
           angles from a blueprint onto metal.

   2. Measurement - The first step in correct layout is to measure with 
       exact dimensions the item being copied using a rule, tape measure,
       dividers, and compass.

       a. The ability to read and measure correctly both whole and 
           fractional dimensions from rule to work and back to the rule 
           requires concentration and counting accurately along the rule.

       b. Practice exercises in drawing lines of specific length (for 
           example, 1 3/16," 5/32," 2 1/8") are recommended before layouts 
           are done on metal.

       c. Practice in measuring and recording pre-drawn lines and listing 
           the correct number and fraction measured is also recommended as a 
           skill building activity.

B. Layout or transfer work is the placement of the measurements and lines
   or outlines on the metal. It is done in full scale and allows for saw 
   cuts or kerf as needed. The measurements are usually taken off the 
   drawing when laying out, but they may be measured directly from a project 
   being copied or duplicated.

C. Layout of a Project for Construction

   1. Using the measurement tools previously discussed, determine the proper
       length and angles required for the project.

   2. Transfer the dimensions from blueprint to metal using one of several 
       methods discussed above. 

       a) Attach a drawing (full size) of the project to the metal. Using a 
           scratch awl, make an outline of the project on the metal. 

       b) Transfer lines from a blueprint to metal using a straight edge and 
           soapstone or chalk. Be sure all lines are straight and angles are 
           correct. 

       c) Use templates or cardboard, etc., to transfer curves and angles.

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         ACTIVITY: 

         1. Draw a paper layout of a parts box and then cut it out and 
             fold it into its finished shape.

         2. Measure an object like a simple box and then transfer 
             the measurements to a paper layout drawing in full scale.
             When the layout is complete, including the dimensions, 
             transfer the drawing to the metal, using a scratch awl.
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7/17/91 YNJ/CC/tf


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