Replying to Avatar anime_outdoor

From my hour or so of reading, it seemed like you could change t4 to t6 by baking at 350F for 10 hours.

Logically if it can be easily hand formed, it would also bend easily under use as a backpack frame, unless it can heat treated after forming.
Avatar
d 2y ago

That may seem logical but it's not true. Even if the pack frame is that open upside down U shape with absolutely no other members, the forces aren't going to be acutely focused the way they are when you're making a bend in a tube using a lot of mechanical advantage.

Now attach the legs of the U together and it becomes much stronger. Constrain the frame with taught fabric, or diagonal stays (could be thin cord), and it becomes stronger still.

If you throw the pack off a cliff and one of the frame members lands on a rock with the weight of the pack on it, sure, you might wreck the frame. But just day to day use? No way.

Reply to this note

Please Login to reply.

Discussion

Avatar
anime_outdoor 2y ago

The frame of a pack is supposed to function sort of like a recurve bow.

Think of pulling the load lifters on the top of shoulder straps as if you are pulling a bow string.

This tensioning is what transfers the weight of a pack from the shoulders down to the hips.

We want the frame to be stiff enough to resist curving under tension, but not overly heavy and cumbersome for the intended load.

Keeping with the bow analogy; a 50lb pull weight is preferred over a 30lb pull weight