Fire Bow Challenge
- Thread starter Jeff Wagner
- Start date
-
Hey Guest, Early bird pricing on the Summer Moot (29th July - 10th August) available until April 6th, we'd love you to come. PLEASE CLICK HERE to early bird price and get more information.
Looking back I wonder if there is confusion about numbers of strokes.
I recall that "forward and back" was one stroke. But I now see that the top post by Jeff currently reads that forward and back is two strokes. So is my four actually eight? Bob's excellent post also may need clarifying on this point.
[Also I seem to have lost one post completely and possibly part of another. Has anyone been editing in this thread? It would be helpful if anything edited or deleted was accompanied by a PM to clarify what has happened and why.]
I recall that "forward and back" was one stroke. But I now see that the top post by Jeff currently reads that forward and back is two strokes. So is my four actually eight? Bob's excellent post also may need clarifying on this point.
[Also I seem to have lost one post completely and possibly part of another. Has anyone been editing in this thread? It would be helpful if anything edited or deleted was accompanied by a PM to clarify what has happened and why.]
No editing here. I noticed the discrepancy but did not wish to detract from the good work you guys are doing. I guess the counting method should not matter all that much so long as we all count the same way.
I totally over-read that part as well (probably just assuming it was 1 stroke going back to forth).
30 strokes to eight seems to be the same kind of teaching experience as 15 strokes to 4
Rich59 still rules bigtime!
I might just go and edith that grin of my face in that video.
I must admit I've shot at least twenty five video's yesterday, trying to get one less stroke on tape, but this was the best shot of them all. My neighbor was looking quite weird at me after hearing me say 'hy, I'm Bob and this....' for twenty odd times.
It's a good laugh as well as a humbling experience!
What kind of fancy thing is that you use as a bearing block, Rich59? It looks like a prostetics shoulder joint of some sort
30 strokes to eight seems to be the same kind of teaching experience as 15 strokes to 4
Rich59 still rules bigtime!I might just go and edith that grin of my face in that video.
I must admit I've shot at least twenty five video's yesterday, trying to get one less stroke on tape, but this was the best shot of them all. My neighbor was looking quite weird at me after hearing me say 'hy, I'm Bob and this....' for twenty odd times.
It's a good laugh as well as a humbling experience!
What kind of fancy thing is that you use as a bearing block, Rich59? It looks like a prostetics shoulder joint of some sort
Thats a damned impressive effort Rich !
Still don't know how to get my own attempts onto video but I'm working on it, though I very much doubt I can top your 4 or 8 (whichever we decide to call it) strokes!
The bearing Rich uses looks to me to be one of the end pieces from a chrome-plated towel rail guys
Still don't know how to get my own attempts onto video but I'm working on it, though I very much doubt I can top your 4 or 8 (whichever we decide to call it) strokes!
The bearing Rich uses looks to me to be one of the end pieces from a chrome-plated towel rail guys
Towel rail end it is. Greased it makes for a low friction bearing.
The post that got lost was along the lines that if you time the 4 strokes you come to about 5 seconds. This could seem interesting compared with the established bow drill record http://wildwoodsurvival.com/survival/fire/bowdrill/DudleyWinnSmithBowdrill.pdf of 7.2 seconds set about 70 years ago.
However Dudley Winn Smith managed the bowing in about 3 seconds and getting it to flame in the next 4. So there is still a lot to learn. Nice one Dudley.
The post that got lost was along the lines that if you time the 4 strokes you come to about 5 seconds. This could seem interesting compared with the established bow drill record http://wildwoodsurvival.com/survival/fire/bowdrill/DudleyWinnSmithBowdrill.pdf of 7.2 seconds set about 70 years ago.
However Dudley Winn Smith managed the bowing in about 3 seconds and getting it to flame in the next 4. So there is still a lot to learn. Nice one Dudley.
Well impressed Richard. I have never seen the bow drill produce a coal that fast.
Am I right in saying that was a clothes rail holder you were using as a bearing block and the cord was wrapped around the drill in the Egyptian style but without the clove hitch in the middle?
Need to know about the drill and the hearth? Knowing you, was that an elder type drill as it seems rather slim? Lots of questions I know.
Cheers
George
Am I right in saying that was a clothes rail holder you were using as a bearing block and the cord was wrapped around the drill in the Egyptian style but without the clove hitch in the middle?
Need to know about the drill and the hearth? Knowing you, was that an elder type drill as it seems rather slim? Lots of questions I know.
Cheers
George
Sorry mate. Started the post, got distracted and you answered one of the question before I asked it.
I'd like to share the ideas that led to a fast bowdrill.
Drill Well, first of all I had done some previous work on a fast hand drill. I think I got it down to under 12 seconds. For that it is pressure, pressure, pressure all the way. So one idea was to use the setup for hand drill and convert it to bowdrill. You need a drill that will deliver good punk at high pressures. Elder is the best I know, so that was the chosen wood.
Drill tip Again from hand drill I knew that in general having a hard outer ring and soft centre got the best results. I reasoned this should also be true of the bow drill. The reason for this I think is that you get all the punk from the highest velocity part of the drill tip - the outer edge without wasting energy also producing punk from the centre where the high pressure/ low velocity will more likely produce a coarse, inferior punk. I could create a ring drill tip like this by 2 methods. A hollow/ pith filled elder stem will do this naturally. I could also form it from a carved elder drill made of solid wood by hollowing out the centre of the drill tip between drilling attempts.
Notch The notch was just deep enough to quickly fill up with hot punk that did not need to fall through cool air a long way to the bottom. Also the apex of the notch was just beyond the "tramline" formed by the spinning, hard outer rim of the drill tip. Therefore all the punk was concentrated in a very small area at the notch apex, so enabling a quickly forming coal.
Bearing block Lowest friction I could manage. I opted for a metal cone, which I oiled with cycle oil.
Top of drill For the carved solid elder drill this was straight forward - I just sharpenned the tip and waxed it with candle wax and leaves. For the hollow elder tube however I had to be inventive as a wooden ring would have been extra friction. I eventually succeeded by finding a nicely fitting metal ring collar and seating a screw with a round head in that metal collar. The slot in the head caused some extra friction but it worked OK as a compromise.
Bow A sturdy, long, straight bow was my choice - about as long as my arm could usefully use. I think it is about 1 ft 9 inches long.
Bow string Green paracord was good and strong. However, a key point was good control of the tension. I put about 6 turns round the drill and wound a tensioner into the cord at one end for final adjustment of tension.
Pressure. I put a lot of weight through the drill.
Hearth - ordinary commercial pine.
That's about it really.
Drill Well, first of all I had done some previous work on a fast hand drill. I think I got it down to under 12 seconds. For that it is pressure, pressure, pressure all the way. So one idea was to use the setup for hand drill and convert it to bowdrill. You need a drill that will deliver good punk at high pressures. Elder is the best I know, so that was the chosen wood.
Drill tip Again from hand drill I knew that in general having a hard outer ring and soft centre got the best results. I reasoned this should also be true of the bow drill. The reason for this I think is that you get all the punk from the highest velocity part of the drill tip - the outer edge without wasting energy also producing punk from the centre where the high pressure/ low velocity will more likely produce a coarse, inferior punk. I could create a ring drill tip like this by 2 methods. A hollow/ pith filled elder stem will do this naturally. I could also form it from a carved elder drill made of solid wood by hollowing out the centre of the drill tip between drilling attempts.
Notch The notch was just deep enough to quickly fill up with hot punk that did not need to fall through cool air a long way to the bottom. Also the apex of the notch was just beyond the "tramline" formed by the spinning, hard outer rim of the drill tip. Therefore all the punk was concentrated in a very small area at the notch apex, so enabling a quickly forming coal.
Bearing block Lowest friction I could manage. I opted for a metal cone, which I oiled with cycle oil.
Top of drill For the carved solid elder drill this was straight forward - I just sharpenned the tip and waxed it with candle wax and leaves. For the hollow elder tube however I had to be inventive as a wooden ring would have been extra friction. I eventually succeeded by finding a nicely fitting metal ring collar and seating a screw with a round head in that metal collar. The slot in the head caused some extra friction but it worked OK as a compromise.
Bow A sturdy, long, straight bow was my choice - about as long as my arm could usefully use. I think it is about 1 ft 9 inches long.
Bow string Green paracord was good and strong. However, a key point was good control of the tension. I put about 6 turns round the drill and wound a tensioner into the cord at one end for final adjustment of tension.
Pressure. I put a lot of weight through the drill.
Hearth - ordinary commercial pine.
That's about it really.
rich59 said:
I'm very impressed by your efforts and results.
One thing I've been thinking is that as it's the outer edge that does the main friction heating is
Why not carve down a center section of a spindle, where the bow string contacts it ( this probably doesn't apply to elder as it's soft centered ) For a straight tube the rotation speed at the outside will be the same speed that the bow string moves, if you carve down a section of half the diameter you get a gearing and can up that to twice the speed, also twice the amount of rotations per string length and half the amount of deceleration/acceleration cycles as you change direction.
Whether it's worth doing might depend on if the spindle and handle the downward presure. For a solid spindle it might be worth either making a small center hole all the way through the hearth or a concave center dome on the spindle.
Similar threads
