- Slides: 17
Reading a Machine Renata Brenner
The Design • • • Machine made - stamped/pressed parts/molded Metal & Plastic (Bakelite) Sturdy Interchangeable/universal – fits multiple machines Gears, ratchet, ball bearings Interchangeable cams –cast Adjustable – Interchangeable cams – changed by hand – Bight adjustment – stitch width – depress lever to slide – Cloth clamp – position • • • Install w/ screwdriver Lubricate Cloth clamp – toothed surface
The Design • • Power input is through fork arm – from needle clamp Drives ratchet – Advances material through path determined by cam on needle upstroke – Moves material back & forth perpendicular to path of needle on needle upstroke – Stripping arm holds cloth down on needle upstroke – Holds material stationary on needle downstroke • • Can be advanced manually with knob Need to cover/retract feeddogs
What were the designers were trying to accomplish?
What were the designers were trying to accomplish? • Sewing machine stitches in a straight line • Create a buttonhole – opening with bound edges (retain shape -prevent fraying)
What is the object designed to do?
Is it part of a system?
If so, where and how does it fit in? • Screws onto machine presser bar • Fits onto needle clamp
What is the expected input and where will its output go? • Device holds and moves fabric in synchrony with the sewing machine needle in order to create a buttonhole
Who would use it?
What they were assuming about the people who would use it? • • Knew how to sew Read instructions/diagrams Use a screwdriver Reasonably mechanical
What is that person expected to know? • Parts and Functions • How to perform basic tasks with the sewing machine
What is she or he supposed to be able to learn? • • • How to install Position/adjust Choose thread/size/style based on fabric/button Adjust width Maintenance: open & lubricate