Outline
• Robot Construction
– Steering
– Locomotion
• 3D Printing
• How to get an A in the lab
– Verifications
– Practical exams
– Lab Write Ups
Bell Crank Style Steering• Link Mechanisms & Arc Compensation
– Four bar with equal crank and rocker lengths
– Four bar with unequal lengths
Bell Crank Style Steering• Servo Placement
– As a functional link:• Simpler (less parts), but tolerances between servo and
opposite arm may cause undesired angles
– As a separate crank arm• Greater design flexibility• Stronger
Bell Crank Style Steering• Link Mechanisms & Arc Compensation
– “Four bar” with equal crank and rocker lengths
– Four bar with unequal lengths (broken couplers)
Locomotion
• 3 most common– “Hoppers”
• Pros: Simple, Reliable,
• Cons: Inefficient
– Crankshafts• Pros: Efficient, and fast!
• Cons: Difficult to build, may run backwards or bind
– One-way partial crankshafts• Pros: Easier than crankshafts, still efficient
• Cons: Harder than hoppers, less efficient than crankshaft
Locomotion: “Hoppers”
• Steep vs. Shallow
– Balance:
• Friction
• Forward Force
• Variable (rotating pin)
– Uses spring to maintain contact
MM
M M
Printing Process
• Reproducing text and images
• Typically ink on paper
• 2 Dimensional
• Prints line-by-line
3D printing
• Selective Laser Sintering
– (SLS)
• Stereolithography
– (SLA)
• Fused Deposition Modeling
– (FDM)
• Laminated Object Manufacturing
– (LOM)
Flashforge 3D Printer Creator Pro Dual Extruder PrinterMakerBot Replicator Desktop 3D Printer (5th Gen)
3D printers for MAE106
Print TechnologyFused Deposition Modeling (FDM)
Fused Deposition Modeling (FDM)
Build volume9.9 x 7.8 x 5.9"
25.2 L x 19.9 W x 15.0 H cm
8.9 x 5.7 x 5.9"22.6 L x 14.5 W x 15.0 H
cm
Layer resolution 100 microns / 0.1 mm 100 microns / 0.1 mm
Filament Compatibility PLA ABS, PLA, PVA
Number of Extruders 1 2
3D printers comparison
Mechanical Verifications (2016)
• Overview– 5 points total
– Each point is pass/fail. No partial credit.
– Fully built robot!
• Rubric1. Robot actuates and exhibits locomotion using only air pressure from the tire
2. Your robot fits in the 12” diameter• Connect your tire with the valve side down!
3. Your robot is the correct height (18” +/- .25” to center of tire)
4. Your robot can roll on the table while steering left and right
5. On time and ready! On track to a working autonomous robot
Lab Write-Ups
• Turned in using CANVAS
• Turned in as a team (3-4 people)!!
– Make sure to put your team number!
• Due in the first 10 minutes of the following lab
• Save as… #TEAM#_01 where 01 is the lab number