Mechanical Drawing and Instrument Use Chapter 3 Mechanical Drawing and Instrument Use

Mechanical Drawing Drawing accurately with the aide of rulers, scales, compasses, etc.

Drafting Board with adjustable angle http://en.wikipedia.org/wiki/File:Zeichenmaschine.jpg

Parallel Bar Ends of the straight edge are controlled by a system of cords and pulleys. For this reason you can move it up and down the drafting board maintaining a horizontal position. www.draftingtables.com/drafting-accessories/drafting-machines/

T-Square It is composed of a head and the blade. When put against the side of a table that is straight it becomes your straight edge that is perpendicular to the table. http://www.draftingtables.com/drafting-accessories/drafting-machines/3883+3890+4294585758.cfm

Triangles All vertical and most inclined lines can be drawn with the 45 and 30x60 triangles. The various degrees that can be used can be found on page 29 in your book. http://www.sas.org/E-Bulletin/2003-06-13/features2/art/triangles.jpg

Compass and Dividers Compass are used to draw circles from about 1” radius to about 6” radius. Dividers are used for subdividing and transferring distances into equal parts http://www.engineersedge.com/catalog/images/305K.jpg

Lead Holder Holds different types of lead in order to draw. http://cdn.dickblick.com/items/206/26/20626-1001-2-3ww-l.jpg

Circle Template Instrument used to trace various sizes of circles. http://www.enasco.com/prod/images/products/27/AC047837l.jpg

Protractor Measures angles. http://www.oppictures.com/singleimages/400/LEO77106_1_1.JPG

Erasing Shield Protects lines on your drawings from being erased.

Scale Used to measure at different scales. http://cdn-write.demandstudios.com/upload//8000/100/20/7/38127.jpg

Drawing Paper Standard Paper Size ANSI Paper Size “A” Size: 8 ½” x 11” “B” Size: 11” x 17” “C” Size: 17” x 22” “D” Size: 22” x 34” “E” Size: 34” x 44” Roll Stock “A” Size: 9” x 12” “B” Size: 12” x 18” “C” Size: 18” x 24” “D” Size: 24” x 36” “E” Size: 36” x 48” Roll Stock

Lead Types Hard Leads Medium Leads Soft Leads Extreme accuracy and line work 9H, 8H, 7H, 6H, 5H, 4H Medium Leads General purpose in technical drawings, lettering, arrowheads, darkening 3H, 2H, H, F, HB, B Soft Leads Not used in mechanical drafting, used for smudging and sometimes in renderings 2B, 3B, 4B, 5B, 6B, 7B

Neatness Lift your equipment Remove graphite from lead after sharpening Never place articles on drawings Wash hands frequently with soap Do not rub eraser crumbs with hand, use the brush Use eraser shield Touch drawing with back of finger nail Do not sweat on drawing When lettering, place paper under hand. When darkening, move left to right if right handed. Or move opposite if you are left handed.