Hey guys,
I just returned from a nice 90 mile backpacking trip on the Appalachian Trail. While there, I had a goal of collecting materials during the hike to make a friction fire. I was able to collect decent, but damp materials, and was very close to getting and ember. I made some key mistakes that kept me from being successful, and i've listed them below.
1) I got lazy and used the same soft popular wood that I made the hearth board and spindle from, for my bearing block. This caused high friction on the top of the spindle, just as the hearth board was smoking good. This would ultimately make the spindle "seize up" before getting and ember.
2) I made a short bow, about a 12 in working stroke length. This might had been ok, if I didn't have the bearing block problem, but it does require more effort. I've found that with bows with about a 18" stroke length or more, it so much easier to build up heat with less effort.
I hope this is helpful.
Ed