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Sheet Metal: From Concept to the Cosmos

118robonauts.org

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Ryan Stockton: Ryan.L.Stockton@NASA.gov
Robotics Specialist-Supervisor for S&K Engineering & Research @ NASA-Johnson Space Center
10 Seasons in FIRST

2016-2017 - Student on Team 118
2018-Present – Mechanical Mentor on Team 118

Co-Lead of the Robonauts Everybot Program
Main author of the NASA RAP Robotics Design Guide

About Me

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Sheet Metal Terminology

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Use standard thickness and bend radius as much as possible
“Box Out” everything
Don’t create sharp bend reliefs….leads to stress concentrations and cracks
For an integrated structure anything thicker than 0.090” thick is usually overkill for FRC

Best Practices

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Materials

Material/Alloy	Yield Strength	Elongation at Break	Uses
Aluminum 5052-H32	28 KSI	12%	Easier to bend without cracking Cheaper Smaller minimum bend radius
Aluminum 6061-T6	40 KSI	12%	Great for places that need higher strength Larger minimum bend radius
Polycarbonate	10 KSI	Up to 138%	Great for High Impact Areas Lighter Quicker to Manufacture Can be Heat Bent

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Bend Tables

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Prototyping

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Design Styles

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118/NASA uses a K-Factor of .44 for all 5052, 6061, and Copper parts
K-factor differs machine to machine, different thicknesses, and different materials
Distance from holes to start of bend: 4X material thickness
Minimum Flange Length: 4X material thickness
Box Bends shall be no deeper than 4” with standard tooling
Base of a C-channel shall be at least 2X the flange length
Standard industry flange length tolerance its +/-.015”
Standard Industry angle tolerance is +/- 1 degree

Critical Numbers

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Design for Manufacturability

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Design for Manufacturability

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Design for Manufacturability

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Bend Relief

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Design for Manufacturability

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Drawings

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Drawings

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Rolling

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Overlapping Bends

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Bump Bending

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Hemming

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Joggle

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Forming

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Forming

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Fasteners

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Fasteners

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Box and Pan brake

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Examples:

2022 Robonauts Robot Chassis

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Examples:

2023 Robonauts Robot Chassis

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Examples:

Lunar Rover Wheels

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Examples:

Micro Rover Chassis

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Examples:

Lunar Terrain Vehicle Chassis

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Examples:

Lunar Terrain Vehicle Crew Step

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Examples:

VIPER Flight Communication gimbal

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Examples:

VIPER Flight Communication gimbal

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Thanks!

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