Improvised Bow Drill

Yesterday my friend and I were hiking in the nearby woods, and we decided to test her bow drill skills. It seems that everything that could pose a problem, did. First, finding adequate tinder, then her soapstone handhold was too soft, so the spindle had drilled almost all the way through at this point, then we realized the bow (with buckskin string) had been dropped somewhere in our travels. So we had to come up with some solutions to fix these problems and ultimately achieve fire.
First, a string for the bow. While I had a backup bow, we were testing her skills, not mine, as well as her equipment on hand. I was merely an observer in this. So after a moments thought, she produced a fine shoelace from her shoe, which served perfectly.
Next, tinder. We managed to locate a piece of bark with somewhat fibrous inner layer.
After giving the set a go, we found problems with the spindle, and realized the wooden spindle had actually bored deep enough into the stone that it was not spinning as freely as one would like, so we needed to find something to replace it, preferably without too much time needed. We weren't the first to visit this spot, and some others had seen this area as a good place to consume alcohol. As such, there was a few beer cans around, so why not try the bottom of a beer can? This worked rather well, surprisingly.
And so we were able to achieve an ember, and with some coaxing, a flame.

Above you can see the shoelace, beer can, and set used. The green coloured stone is the soapstone handhold.