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15 Months in the Real World. Colin Sutherland. Overview. Background My Job A little project…. A little background…. Oakville is the only GE lamp plant in Canada Had 60 th birthday this August. Makes 3 lamp types Incandescent PAR (Parabolic Aluminum Reflector) Fluorescent Tubes.
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15 Months in the Real World Colin Sutherland
Overview • Background • My Job • A little project…
A little background… • Oakville is the only GE lamp plant in Canada • Had 60th birthday this August • Makes 3 lamp types • Incandescent • PAR (Parabolic Aluminum Reflector) • Fluorescent Tubes
“Electrical Engineering Intern” • Ambiguous, like many things in the real world • Jobs included: • Ordering parts, dealing with suppliers • Updating/creating new electrical schematics • Production/downtime reporting • PLC Programming • Organizing, working with electricians • Etc • More like “Electrical Engineer”
Coating Problems on Light bulbs • Coated to reduce glare from the uncovered filament • Coating defects very visible when bulb lit up. • Not good for decorative lamps! • Defects = Shrinkage and recalls = waste = $ lost!
Coating Process Assembly Machine Conveyor Coater Oven Bulb Boxes In Bulbs Out Spacer Dumper
What was wrong? • Average DPM (Defects per million) of 2577 • Very High Variance and excursions
Why? • Old system used a motor to detect powder height • Powder high -> motor has more resistance -> can be measured • Problem? • Powder is messy! Can gum up mechanical systems • No visual feedback on height. • Hard to adjust
Why? • Photoelectric sensor to check for powder density • Sensitivity has to be manually adjusted • Again, no feedback, no alarms when rejects occur!
Improving • Other sensors tried in the past did not work • Needs to be accurate, and resistant to dust • Solution: Laser distance sensor • Visual feedback • Multiple Outputs Prototype set up
Improving • Used laser sensor to check for coating density • More accurate • Easier to adjust • Multiple Outputs • Open at top for easy cleaning • Tube at bottom to limit powder flow up into bracket • Air piped into tube from back to keep powder out
Results • 2008 Average of 668 DPM • Variance reduced
What did I learn? • You can never make something foolproof enough • People will always find ways to mess things up • Need as much redundancy as you can fit in • You can’t anticipate every possible scenario in time • But you need to • Might have to add functionality afterwards • Important to have clear documentation