Tuesday, July 19, 2011

Back to Work

The first prototype is basically finished.  Well 90%.  The last 10% is a real pain because I need to make the straps longer and come up with some way to attach them to the pack for testing.  I know how they need to be attached in the future but currently i need to test some variations and it's a bit more work.  Truly this is the critical step in my initial design prototyping.

Getting the pack to this point was full of delays and challenges.  I thought I could be here weeks ago but I had difficulties with the sewing machine that took while to figure out.  Apparently you need a special needle for heavier gauge thread, and that made the machine jam up every time I tried starting a stitch.  Plus the tension was all wrong.  That was frustrating but I now know the machine a lot better.  I first sewed the sides to the front and then to the back.  That part was pretty easy although the curved sections proved to be a pain in the butt.  I know I can find a better way to do that.  Something repeatable, because I sit here and design this, I am totally thinking with an eye towards a small scale production.  If this project goes anywhere, that's where it will end up.  The hip belt was a little difficult getting straight with the whole pack sewn together.  Next time, I will sew that onto the back panel first.  That and the shoulder straps.  It is way too much of a pain sewing those on last.  I like what I did with the straps.  I made a 6 inch long piece of fabric that I sewed on to the pack as an upside down T.  The piece extended 2" off the pack and was angled at just the right angle of my shoulders.  I am not sure where the strap should sit yet, closer to the outside shoulder or closer to the neck, but with the 6" length of my attachment piece, I can vary the strap placement pretty easily.  I would also like to do something like that with the bottom of the shoulder strap but there is too much variation in what I would like to try right now.  That is whats throwing me off right now because I have 4 different ways that I want to take this right now.  I'm not real sure how to do comparison testing without make separate prototypes.  I think I just need to make one model and try it out and then vary the position and try it again.  That will give me a lot of additional data to use as I move forward and make another model.  The hip belt is a real small 1" wide strap that I had lying around.  It works but I'm not sure how well it will do with weight in the pack.  Right now with a sleeping bag and a tent rain fly in it to hold its shape, it is extremely comfortable.

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