How to get an A in MAE 106

April 7th, 2017

Sumner Norman

Outline

• Robot Construction

– Steering

– Locomotion

• 3D Printing

• How to get an A in the lab

– Verifications

– Practical exams

– Lab Write Ups

Episode IV: Attack of the Anthill

• Remember to review the project rules periodically

Robot Construction

Steering

Steering

Bell-Crank Rack and Pinion

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)

Rack and Pinion Steering

Ackerman Steering

Robot Construction

Locomotion

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

Locomotion: CrankshaftsConverting linear rotational energy

Locomotion: Crankshafts

• Singularities & moment arms

Crankshafts

• Pin joint your piston!

Crankshafts

• Singularity fixes

– Friction

• Bearings!! ( > 6)

– Parallelism

• 1DOF (binding)

Crankshafts

• Singularity fixes

– Momentum & Balance

Crankshafts

• Singularity fixes

– Piston timing

3D Printing

Manufacturing

• Subtractive Manufacturing

Manufacturing

• Additive Manufacturing

Manufacturing

• Additive Manufacturing

Additive Manufacturing

• Bio 3d printing

Printing Process

• Reproducing text and images

• Typically ink on paper

• 2 Dimensional

• Prints line-by-line

Additive Manufacturing

• 3D printing

– Adds material layer-by layer to create complex parts

3D printing

• Selective Laser Sintering

– (SLS)

• Stereolithography

– (SLA)

• Fused Deposition Modeling

– (FDM)

• Laminated Object Manufacturing

– (LOM)

Selective Laser Sintering (SLS)

Stereolithography (SLA)

Fused Deposition Modeling (FDM)

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

How to get an A in the Lab

Practical Exams

Practical Exams - Circuit Quality

Fritzing & Wiring Diagrams

How to get an A in the Lab pt. 2

Verifications (how we grade your robot)

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

How to get an A in the Lab pt. 3

Lab Write-Ups

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

Lab Write-Ups

Lab Write-Ups

How to get you got an A in MAE 106

April 7th, 2017

Sumner Norman