Poster/update

For the poster critique, I looked at a poster from the lab about implementing FREE actuators (fiber reinforced elastomeric enclosures) as an active orthosis on crutches.  The basic idea behind the poster came through clearly -- that FREE acuator orthoses would be a novel way of reducing wrist pain associated with use of crutches.  The advantages of such a system over a passive orthosis were not made clear in the poster.  Any possible advantages of one idea over another are an important point to make clear especially when presenting research on alternate means of achieving a goal. There was a section describing how the investigation met the CCEFP's goals, but this part still didn't compare an active orthosis to a passive orthosis.   

The pictures in general were self explanatory, however the pictures pertaining to manufacture of FREE left too much to the imagination.  Had the presenter been present, a few questions would have clarified FREE manufacture, but fewer photographs and more schematics/drawings might eliminate the need for these questions in the first place.

 The concept of human power harvesting was very well laid out and easy to understand.  The text of this section complimented the pictures.  Together, the text and diagrams of this section facilitated a thorough understanding of the idea being discussed. 

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Project update:

All neccessary parts and materials for the reiteration of the PPAFO gear mechanism have been ordered.  Machining has commenced.  Gears are to be cut via wire EDM by the school's machinists.  Other components are to be cut via CNC end mill.  Overall, we are confident and hopeful as we begin to assemble the design we've been working on this summer (though the steel we are using for gears is not ideal.)  There are many steels with higher fracture toughness, hardness and strength than AR500, but none are as cheap.  Additionally, it seems any other steel we could have selected would have required heat treatment, carburizing, and/or aging in order to achieve the desired material properties.  AR500 it turns out will not have anywhere close to an infinite fatigue life, but it was good to know that materials do exist which would enable this design to achieve an infinite fatigue life.

It will be exciting to see what comes back from the machine shop and how it all fits together to make a complete mechanical system.