Can someone give an explanation of what this guy is doing?

[OTDEAN]

Just puzzled what this guy is doing with the two lines he has drawn and then using a straight edge when tillering.  Starts about 14:13.  https://www.youtube.com/watch?v=YlhaotFqL4Y

Can anyone explain how the two lines are used with tillering and the straight edge?

Cheers

[Weylin]

Yes, I use this technique sometimes on wonky staves like that. Basically, it's hard to judge the tiller by eye when the stave is not straight. The dips and wiggles trick your eye. By drawing a straight line on the side of the bow and then bending the bow you can measure the deflection of the straight line. You hold a straight edge against the line and judge the gap between the straight edge and the curved line.  If the straight lines have a consistent deflection then the limb is evenly stressed, despite what the character of the wood is doing.

[Limbit]

I'm working on a pomelo wood bow right now that is all wonky like that and I am just scratching my head on the tiller at this point. Seems like this will help. Thanks for posting and thanks Weylin for the explanation.

[High-Desert]

Just a suggestion, but some staves are so wonky that it’s hard to get a single line that ends up making contact through the whole stave, so a couple colored lines at intervals make it easy to keep track of which line you are referencing down the stave....if that makes sense

[Swamp Thang]

Just puzzled what this guy is doing with the two lines he has drawn and then using a straight edge when tillering.  Starts about 14:13.  https://www.youtube.com/watch?v=YlhaotFqL4Y

Can anyone explain how the two lines are used with tillering and the straight edge?

Cheers

Thanks for the find never seen this before

[JW_Halverson]

This technique is a limbsaver when working wonky bows.

[Badger]

   That is about the only way I can do a wonky stave. I just don't have the eye to see the slight changes.

[Rākau]

This will be so helpfull with the current bow I'm trying to tiller out. One limb is dead strait like a cut board and the other has a hump and a bit of reflex that is doing my head in. Stoked this got posted.