Fastening and Attaching

We learned of three different fastening and attaching methods in class a few days ago.  The first was through a method called heat stake.  Essentially, a plastic stud piece that is fitted through a plastic ring is melted down by the heat stake machine into what appears to be a button.  Through our group's trial and errors, we learned that giving the pieces ample time to cool and prying the final piece off the machine slowly yielded the best results.  I think this method yields a very strong and sturdy attachment for two pieces.  However, there may be some difficulties designing the pieces such that this method can be used.  The added benefit in its resilient immobility consequently limits it from being used for hinges.  I think in the next windlass project that we are about to design, this piece will most likely be used to build a solid base but not for any of the moving parts.  Just as a thought, I might try to combine this method with another fastening method below to make an even stronger base.

The next method we used was the bushings.  I find this method the most difficult since it requires such precise measurements on behalf of the designer and the slightest thousandths of a millimeter makes a difference.  We noted that three different rings yielded three different fits.  A diameter of 0.2600 yielded a loose fit which allowed the pieces to spin around each other, 0.2545 yielded a snug fit which could be used to isolate sections in a piece if need be, and 0.2500 yielded a tight fit which would be used as an end piece.  I was amazed by how the smallest difference in diameter could yield such drastic differences in how the pieces moved together.  I am definitely daunted by the possibility that I will have to use this method, but it will ultimately be a good experience in the end.  I envision myself using this method to work on the turning pieces of the well but I may use the next method instead since I find it so interesting.

We next learned of using piano wires as hinges.  To be honest, I was a little apprehensive about using such a powerful machine despite the fact that my engineering friends use these machines and even more dangerous ones all the time.  However, upon learning how to use them, I was surprisingly excited to know how to use one and this might be my favorite fastening method if only because it's rather fun to use the machine.  In this method, we used a drill bit to drill a hole into a piece of plastic and the machine to again push the wire through the hole.  Again, the nuances of just a thousandths of a millimeter makes a huge difference in how the pieces move but I find it to be much easier than bushings since the drill bit is really the only part that determines how loose the hinge will be.  I think using piano wire instead of bushings will make my life easier (and quite honestly more entertaining) when I design the well lass so there will be a clear bias in my design (unless the bushings work better of course).

Our last fastening method, and one that I could use in conjunction with the heat stake method, was designing two separate pieces in Solidworks to fit together.  The idea is that the dimensions will be so exact, to the thousandths of measurements again, such that trying to separate the pieces will be almost impossible without the help of pliers.  I think this method would best be used to design the base of the well lass but it also means that it cannot be used in any of the hinge designs.  Since the laser cutting machine was malfunctioning that day, we were unable to make the pieces.  However, I would be curious to attempt this method later when I am designing the well lass.