Engineering Library: Difference between revisions

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# Use the charts to find an O-ring that fits your geometry
# Use the charts to find an O-ring that fits your geometry
# Flick between pages 29 and 30 to finalise the housing dimensions and tolerances
# Flick between pages 29 and 30 to finalise the housing dimensions and tolerances
* There are nuances when it comes to robust seals, so follow the guide as closely as possible. General tips:
* There are nuances when it comes to robust seals. General tips:
** Choose as large a cross-section as possible to give yourself as large a tolerance as possible for achieving a nominal squeeze.
** Choose as large a cross-section as possible to give yourself as large a tolerance as possible for achieving a nominal squeeze.
** Radial seals are generally more robust than axial seals, and if using a radial seal, choose a piston seal over a rod seal as it's easier to machine and inspect a groove on the OD of a rod than on the ID of a bore.
** Radial seals are generally more robust than axial seals, and if using a radial seal, choose a piston seal over a rod seal as it's easier to machine and inspect a groove on the OD of a rod than on the ID of a bore.
** Grease the O-ring, even if it's a static seal, to ease assembly. It can also help to seal a gas against a surface finish which is not smooth enough (''vacuum grease'').
** Grease the O-ring, even if it's a static seal, to ease assembly. It can also help to seal a gas against a surface finish which is not smooth enough (''vacuum grease'').
** Beware of hysteresis in dynamic applications. The greater the nominal squeeze, the greater the effect.
** Beware of hysteresis in dynamic applications. The greater the nominal squeeze, the greater the effect.
** Follow all the other recommendations in the design guide as closely as possible, not forgetting surface finish, lead-ins etc.
** Follow the design guide recommendations as closely as possible, not forgetting surface finish, lead-ins etc.


==Manufacturing methods==
==Manufacturing methods==
===Injection Moulding===
===Injection Moulding===
* [https://www.dupont.com/content/dam/dupont/amer/us/en/mobility/public/documents/en/General%20Design%20Principles%20Mod%201.pdf DuPont Engineering Polymers - General Design Principles]. * In the UK, DuPont also offers a complimentary day course which covers the basics of designing for injection moulding.
* [https://www.dupont.com/content/dam/dupont/amer/us/en/mobility/public/documents/en/General%20Design%20Principles%20Mod%201.pdf DuPont Engineering Polymers - General Design Principles]. * In the UK, DuPont also offers a complimentary day course which covers the basics of designing for injection moulding.
* [https://www.protolabs.com/en-gb/resources/design-aids/ Protolabs injection moulding design aids]. It includes  
* [https://www.protolabs.com/en-gb/resources/design-aids/ Protolabs injection moulding design aids]. It includes:
** An order page for a free 'design cube', an excellent tool for giving you a hands-on feel for the different features that are possible, and general design dos and don'ts.
** An order page for a free 'design cube', an excellent tool for giving you a hands-on feel for the different features that are possible, and general design dos and don'ts.
** A material selection guide.
** A material selection guide.
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===Academic Research===
===Academic Research===
* [http://sci-hub.st/about Sci-Hub], a database of free academic papers.
* [http://sci-hub.st/about Sci-Hub], a database of free academic papers.
: Although research is nearly always taxpayer-funded, with authors receiving no royalties, most papers remain stuck behind publishers' paywalls. Accessing Sci-Hub is illegal in many countries, so use a VPN if required.  
** Note: Accessing Sci-Hub is illegal in many countries, so use a VPN if required. Although research is nearly always taxpayer-funded, with authors receiving no royalties, most papers remain stuck behind publishers' paywalls. Sci-Hub is a way around this issue.
: Alternatively, directly ask the author for a copy, through their university email or ResearchGate, or try and find it through an open-access publisher.
** If you do not wish to use Sci-Hub, an alternative option is to ask the author directly for a copy, either through their university email or ResearchGate. You may also find it through an open-access publisher.
* [https://ntrl.ntis.gov/NTRL/ National Technical Reports Library], a free open-access database of US-funded research.
* [https://ntrl.ntis.gov/NTRL/ National Technical Reports Library], a free open-access database of US-funded research.



Revision as of 12:51, 21 June 2023

This page contains a list of mostly mechanical engineering resources.

Some contain lots of technical detail. If you find yourself scratching your head, contact a relevant supplier for support. They typically have applications engineers with deep technical expertise to help answer questions quickly.

Design

Data and formulae

Dimensions and tolerancing

  • Tolerances of Manufacturing Processes, a short guide explaining tolerances achievable using typical manufacturing processes. Consult your go-to manufacturer if you think your tolerances might be challenging.
  • GD&T chart, a well-illustrated chart explaining the different geometric tolerance types. Beware of subtle differences between ASME Y14.5 and ISO GPS.
  • Limits and Fits chart, a set of tables for identifying and specifying fits. Having a set of pin and ring gauges to hand, which have varying clearances, is useful for getting a hands-on feel.

Materials databases

  • UL Prospector, a database for finding a material and its supplier.
  • MatWeb, a database for finding material properties.
  • Total Materia, a database for finding more detailed and proprietary material property data, which costs, but might be useful for detailed analytical calculations/FEA.

Human Factors

Component selection

Fasteners

  • NASA Fastener Design Course, a comprehensive course covering all things fastener related, including '...materials, plantings and coatings, locking methods threads, joint stiffness, rivets, inserts, nut plates, thread lubricants, design criteria, etc.'

Adhesives

  • Henkel Adhesive Selector, a tool for identifying an appropriate adhesive. Don't neglect surface preparation (cleaning/abrasion/priming).

Seals

  1. Review page 29 to determine the housing arrangement
  2. Use the charts to find an O-ring that fits your geometry
  3. Flick between pages 29 and 30 to finalise the housing dimensions and tolerances
  • There are nuances when it comes to robust seals. General tips:
    • Choose as large a cross-section as possible to give yourself as large a tolerance as possible for achieving a nominal squeeze.
    • Radial seals are generally more robust than axial seals, and if using a radial seal, choose a piston seal over a rod seal as it's easier to machine and inspect a groove on the OD of a rod than on the ID of a bore.
    • Grease the O-ring, even if it's a static seal, to ease assembly. It can also help to seal a gas against a surface finish which is not smooth enough (vacuum grease).
    • Beware of hysteresis in dynamic applications. The greater the nominal squeeze, the greater the effect.
    • Follow the design guide recommendations as closely as possible, not forgetting surface finish, lead-ins etc.

Manufacturing methods

Injection Moulding

Die Casting

Inspiration and Learning

Mechanical Engineering 101

Machines and Mechanisms

Reverse Engineering

  • Big Clive's YouTube channel, a channel with teardowns of cheap and cheerful consumer products. The focus is on electronics, but includes some mechanical design too.
  • Fictiv Teardowns, a catalogue of teardowns of high-end consumer products.
  • AvE's BOLTR series, a YouTube channel with a teardowns of mechanical hand tools. His BOLTR playlist doesn't include his recent releases, so scroll through his video uploads instead.
  • Munro Live Teardowns, a YouTube playlist covering teardowns of car components, with a focus on benchmarking and costing.
  • WeberAuto, a YouTube channel with teardowns of car components, with a focus on technical detail for training automotive engineers.

Textbooks

Academic Research

  • Sci-Hub, a database of free academic papers.
    • Note: Accessing Sci-Hub is illegal in many countries, so use a VPN if required. Although research is nearly always taxpayer-funded, with authors receiving no royalties, most papers remain stuck behind publishers' paywalls. Sci-Hub is a way around this issue.
    • If you do not wish to use Sci-Hub, an alternative option is to ask the author directly for a copy, either through their university email or ResearchGate. You may also find it through an open-access publisher.
  • National Technical Reports Library, a free open-access database of US-funded research.

Other

Medical Device Development

Microfluidics

NASA Technical Standards

DIY