Stringless fire drill

[Longstrider]

Les Marshalls thread on alternative methods of fire by friction got my mind wandering. One idea I came up with (though not suitable for Les's application) was to make a fire drill without a stringed bow. I thought of making the drill with slots or deep groves along it's length, effectively making it into an elongated cog wheel. Then the "bow" would carved into notches like a bow-saw blade. With the notches carefully spaced to fit the cog teeth around the drill you could then use a sawing action to rotate the drill as with the normal fire drill.
I imagine that wood selection might be pretty important on this one, as the teeth on the saw/bow would be prone to snapping off pretty quickly if the wood was not strong enough.
If anyone has tried this and failed miserably, please let me know before I start whittling into pieces of wood for what might prove to be hopeless task.

 

[Ogri the trog]

I don't want to ruin your thread Longstrider,
But that just sounds like an over-complicated fire saw to me.
I'm not saying that it won't work but it does sound as though there would be much more in the preparation stages for no significantly greater gain.

ATB

Ogri the trog

 

[bloodline]

It might be possible to make something like that in a warm tidy workshop but I wouldnt want to make one "in the field" I had enough trouble making and finding the bits for my fire bow.

Peter A

 

[rich59]

I have done a "thought experiment" in the past almost exactly as you describe Longstrider, but did not get round to the practical. Do have a go.

A practical question about this method is how effective the one-sided power house will be in getting the drill to turn in its two end sockets. Both bow and drill generally give a balanced force round the drill.

You might find you needed to get the depression formed with bow or hand drilling before the cog system became stable enough to use.

A variation on your proposed system is to have two "bows" - one each hand - like hand drilling. Then you need a third hand for the top socket (or use your teeth or forehead) for the downward force.

Or, if you had a spiral cog system on the drill you might get downward force too?

 

[Tadpole]

If you were looking for a purely practical solution to making a fire “drill” with out a string, you could do worse than going back to old fashioned “drill” for example

The brace and bit style drill made from a thick wooden board with a wide offset cranked handle. I am sure that with practice this would work and has the advantage of being easily constructed from materials available to most people

fixing the wood dril in the jaws would be a case of jamming it in a split and whipping it tight

 

[g4ghb]

better still surely you could make a bushcraft version! (carveing a suitable shaped log wouldn't be too difficult )

- the idea's brilliant btw - is soooooo simple - why did we not think of it before!

If you were looking for a purely practical solution to making a fire “drill” with out a string, you could do worse than going back to old fashioned “drill” for example

The brace and bit style drill made from a thick wooden board with a wide offset cranked handle. I am sure that with practice this would work and has the advantage of being easily constructed from materials available to most people

fixing the wood dril in the jaws would be a case of jamming it in a split and whipping it tight