Both of those two were welded top and bottom but as my welding skills are highly dubious one failed and so I cut a small portion off the bottom of the threaded bar. It still feels good in the hand though.
With paracord I do have to re-adjust the length and I use my thumb to alter the tension while bowing.
I to like to carry several means of fire-starting. Fresnel lenses, ferro-rod, lighters (I think I bulk purchased about 300 in total lol) and of course flint n steel :)
I think I uploaded a bow-drill video to d-tube a few months ago. I'll see if I can dig it out........
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I can't get it to play on my Linux computer but it might work for you.
Next time someone ask you if you have a light pull out a ferro-rod and hand to them for their smoke. LOL you would get a heck of a look.
Even stranger looks if I get out the flint, steel and char-cloth ;)