Tillering: What now?

[WhistlingBadger]

Tillering a juniper heartwood/bison sinew kids bow.  In this picture it's drawing 10# at 16".  A mammoth killer for sure!     It is about 44" tip to tip; bendy in the handle.  Would like to get it to around 20" if possible; is that realistic without breaking it?  What are you seeing tillering-wise?

Thanks!

[WhistlingBadger]

Here's what's puzzling the daylights out of me:  The right limb looks stiff to me, but it's actually bending further, judging by the lines on the wall.  What the heck?

[mmattockx]

I've never tillered a bendy handle bow, so this may be completely wrong. I'd get the mid limbs bending more, it looks to me like it's trying to hinge just out of the handle area on both sides with the limbs both stiff.


Mark

[Pat B]

The inner 1/3 is bending too much. Give the limbs some scrapes at mid limb to get them bending more there. No more at the handle.

[bjrogg]

I agree . It’s doing most of its bending in and right out of handle.

When I tiller, I don’t just look at bend. I look at limbs and look for straight spots. Spots that aren’t bending enough. It seems to help my eye see what isn’t a bow.

Bjrogg

[organic_archer]

Too much bend in the center and two possible hinges forming - first one right out of the handle and another mid-limb on the right side.

For a kid's bow, it'll shoot with a bell shaped tiller, but could take more set and have more shock than necessary. I'd get the outer 1/2 of both limbs bending more while watching out for that thin spot.

Don't just look at the bend or the distance of limb travel. I see lots of thick and thin spots. Run your fingers up and down the limbs often (like you're gripping a sandwich) to feel for thick and thin spots. They'll jump out clear as day.

It's hard to judge the tiller without a shot of the resting front and side profile. I imagine this bow needs an even thickness taper from handle to tips, which is where your fingers come in.

[WhistlingBadger]

Too much bend in the center and two possible hinges forming - first one right out of the handle and another mid-limb on the right side.

For a kid's bow, it'll shoot with a bell shaped tiller, but could take more set and have more shock than necessary. I'd get the outer 1/2 of both limbs bending more while watching out for that thin spot.

Don't just look at the bend or the distance of limb travel. I see lots of thick and thin spots. Run your fingers up and down the limbs often (like you're gripping a sandwich) to feel for thick and thin spots. They'll jump out clear as day.

It's hard to judge the tiller without a shot of the resting front and side profile. I imagine this bow needs an even thickness taper from handle to tips, which is where your fingers come in.

You were exactly right about where the hinges were.  I got it to brace and did some work with the gizmo, and it found that right mid-limb weak spot.  I don't see these things with my eyes the way some of you can, though.

Feeling up and down the limb for thin and thick spots--yep, I forgot about that.  Well, that's why I did this bow, to learn.

[willie]

I don't see these things with my eyes the way some of you can, though.

in the shop, I hold a CD at arms length when looking at the bow on the tiller tree
I have a 3" disk I can hold up at about half an arms length when looking at bows in pics on the computer screen