Reverse Engineering

Basics

• The process of taking an engineered device/software (thus it is already "engineered" / built and needs no further engineering), and backtracking/deducing how it is designed, and why it was designed that way
• It can even be done to determine what something is/what it was used for, although this is more relevant for archeologists/museums etc, not OSE's context
• For OSE's Context it is mainly taking Old Hardware that has been seldom used/redesigned (due to being obsolete in today's conventional economic system) and reverse engineering them to regain that foundation pre-iterating on it:
  • An example would be acquiring an old Stationary Engine ( such as a Hot Bulb Engine or Crude Oil Engine ) and reverse engineering it. After that one could take that foundation and build a modular version made with modern methods, that hopefully also meets modern emission/efficiency standards etc (not a 1-to-1 duplication)

Notes

How to reverse engineer anything.

Using Baidu (China's Google) and knowing some chinese gets you to design schematics online, from China with love.

Reverse Engineering Lab

• Reverse Engineering Lab Construction Set

Essentially Though:

External Structure / Large Component Measurements

• • 3D Scanner (Large Handheld Type) (Also Photogrammetry )
    • And/or Calipers + Tape Measure + Level / Protractor / Rotation Dial / Angle Dial
  • CAD

Internal Structures / Small Components Measurements

• Typical Tools for Disassembly (Stuff For Fasteners, Stuff For Removing "Permanent" / Tamper Evident Seals (Re: iFixit 's toolkits)
• Overhead Camera / Tripod , or even a separate person acting as the Videographer to capture what all went into taking it apart (To make re-assembly etc easier)
  • Taking photos before each step can work to an extent, but can leave gaps in the knowledge
• Labeled Parts Bins/Containers
• Calipers and/or scAnt / Smartphone Photo Studio for #3DBenchy and tiny stuff / similar Small Part Turntable Style 3D Scanners

Material Analysis

• In Order of Increasing Cost/Complexity:
• A Well Trained Person + Simple Tools Like a XACTO Knife etc
  • RE: BOLTRs by AVE
• Optical Microscope (Etchants/Laser Engravers can be used to Delid IC Packages if they are unlabeled to learn more
• Universal Testing Machine
• Plastic Scanner
• OpenRaman
• XRF Gun
• Industrial CT Scanner
• Electron Microscope / Atomic Force Microscope

Methodology

If The Hardware in Question is on Hand

• An important thing to note is if/to what degree the investigation will be "destructive"
  • A Mass Produced Robotic Actuator could be dissected in a more rough and destructive manner than some mechanical artifact in a Museum! (For some odd things that are so old only a few still exist / Flops Cultural and Historical Value should be considered and preserved as well
• After all that is planned out:
• One starts from the least invasive and most towards the "outside" as possible
• So taking dimensions with the Tape Measure/Calipers, Taking Pictures, and using a Handheld 3D Scanner if Applicable are done
  • Think of it almost like an Archeological Dig / CSI Scene in this phase
• Next the disassembling begins
• First remove all fasteners that can be removed
  • Take note as to if / what type of Threadlocker etc is used
  • Another thing to note is any Grease / Lubricant / Water Displacement Fluid used, potentially take samples along the way for Chemical Mixture Reverse Engineering
• Once this is done one can move on to "popping tabs" and Bypassing Tamper Evident Seals / Preforming Cuts if need be
• If another "layer" is encountered, one should return to the first step of measuring + photographing
• It would preferably be done throughout the whole process, but especially as that first step is done less and less, and the periods of "disassembling" grow longer one should document the process by something like an Overhead Camera , A Helmet Camera or POV Video / VR180 etc
• As parts are taken out they should be put into separate LABELED containers to allow for later re-assembly etc (unless a very destructive approach is taken/only certain parts are of interest (a certain gear system or a chipset found inside the guts and unlabeled)
• The lowest level at this "phase" that one will stop on will be PCBs
• These get sent to another phase/station that is very similar to Microelectronics Repair in composition/expertise
• There they can use their Inspection Microscopes etc to view and document the PCB Schematics (if none are available)
• If there are any unknown components these can be Desoldered and sent off to the final "phase" for processing
• The "Final Phase" Consists of Determining What Specific IC's, Materials, And Chemical Solutions/Mixtures were used
  • For instance Dyson Cinetic 's Cyclone Depends on the Elastomer at the tip of the nozzle being the proper Shure Hardness to allow it to ossilate and self-declog or the whole system clogs up. This is not published, but if you get an old used unit, and a Durometer you can be good to go!
  • Another thing could be determining what type of plastic, or what alloy of metal was used for a structual member
  • Finally, even at the PCB level some companies will attempt to hide what they are doing/what they used. IC Packages can be De-Lidded and investigated with various microscopes to determine what they are, and thus better fill in the schematic

Interesting Case Studies

• Rocketdyne F-1 / F-1b Engine (As per This Video by the YouTube Channel "Curious Droid" Titled "Why Can't we Remake the Rocketdyne F1 Engine?" (~5 Minute Watch) (Basically all of the Fuel/Oxidizer Injectors Were Hand Brazed Into Place and the Skill that required (Practically it's own profession, similar to Boilermakers but more obsolete) was gone, and they didn't Document Everything )
• FOGBANK (A material used in thermonuclear weapons, believed to be an Aerogel . It was made, then the plants were shut down and people moved on. Decades later they needed to make more when refurbishing the USA's arsenal. They had to spend millions to reverse engineer it, then it turns out chemical impurities (for better or for worse) were essential to it's function, in a similar manner to how This Video by the YouTube Channel " Tom Scott " Titled "How they saved the holes in Swiss cheese" mentions that the wholes only form around essentially dirt particles. Granted again security reasons applied in this circumstance, but it shows the importance of detail in reverse engineering and how Documenting Everything prevents the need

Internal Links

• Chinese Reverse Engineering
• Items of Interest for Reverse Engineering

External Links

• The Wikipedia Page on Reverse Engineering
• Seminal work from Bunnie Huang on reverse engineering of hardware - [1]

• Bunnie's video - https://www.youtube.com/watch?v=msrTR3hNDQM#t=161

• Software reverse engineering - [2]