Raptor Reloaded: Design and Intent

The Raptor Reloaded

The Raptor Reloaded

The team behind the original Raptor has released the Raptor Reloaded, an updated and re-factored version of the Raptor Hand.  The entire device was modeled in Fusion 360, a free CAD tool that can import and export most standard solid body modeling formats such as STEP and IGES.  By designing the hand in a tool compatible with numerous CAD packages, we hope to lower the barrier to contribution to the e-NABLE project for engineers and designers.  Previously, if a designer wanted to make a small adjustment to a part of a hand, they’d have to rebuild the entire part in their CAD software before they could make the change.  Now they can download the source files and just spend their time making the specific change they had in mind.  With this new set of source files, we hope to improve the pace of research and development within the design community.

Changes in this design include:

  • Improved print-ability due to custom modeled supports
  • Cyborg Beast compatible sizing
  • Improved dovetail geometry
  • New tensioner retention clip
  • Easier to use tensioner pins
  • Low profile elastics with two tie-off options
  • More access to elastic and flexsor routing channels
  • Debossed versioning information on palm and gauntlet
  • Slimmer, more anthropomorhpic fingers
  • Narrower knuckle block
  • More intuitive assembly (new one-way proximals)
  • Thorough documentation and modular design
  • Source files in native Fusion 360 format, also STEP and IGES
  • Additional velcro-mounting options as well as traditional velcro loop and leather options
  • Re-oriented snap-pin head recesses to improve printability
  • Knuckle pins are now removable, making the hand easy to repair and upgrade
  • Strengthened tie-bars on finger tips

Iteration and Testing are Key

Now that the design is ready, I’d like to share a bit about the process behind the design.  It was a long process involving hundreds of hours of design and print time as the team iterated up on the palm, the phalanges, the gauntlet, the tensioner, and all the snap pins.  Every piece was printed on multiple machines by multiple team members to ensure stability and functionality across different 3D printers.  Numerous small changes were implemented to facilitate easy and reliable printing.

 

And on the CAD side, we did even more iterations.

And on the CAD side, we did even more iterations.

Behind the scenes of the testing process.  Iteration and rigorous testing is the key!

Behind the scenes of the testing process. Iteration and rigorous testing is the key!

 

Comparing the new palm with the Raptor Original, left, and the Cyborg Beast, right.

Comparing the new palm with the Raptor Original, left, and the Cyborg Beast, right.

By just printing parts of teh palm, gauntlet, and fingers, we could test fit and motion much faster than by printing out the entire part.

By just printing parts of the palm, gauntlet, and fingers, we could test fit and motion much faster than by printing out the entire part.

A Design Is Only as Open as It’s Documentation

As an open source community developing open source hardware designs, it’s important to design for accessibility and transparency.  This means structuring the very design files themselves for easy manipulation and readability.  While an on-going process, the Fusion source files for the Raptor Reloaded are annotated to provide designers with information about the relationships between 2D and 3D data, much like comments in code help developers interpret and understand code.  Next, we documented all the important mechanical interfaces of all the parts of the design, allowing any designer to design something that will be compatible with the Raptor Reloaded just by looking at the schematics.  This is a lot of information to manage and we will be posting all source files and schematics to our github soon.

Every part of the Raptor Reloaded has been carefully diagramed to allow designers to leverage the design's modularity and make compatible parts.

Every part of the Raptor Reloaded has been carefully diagramed to allow designers to leverage the design’s modularity and make compatible parts.