Tiller check

[ajbruggink]

Hey guys,

This is a bow I've been working on and I'd like to get some advice on its tiller. This is a rawhide backed red oak board stave and it is intended to be a D-bow. It was once 72" but it is now 64" due to shortening it, it was originally 1 3/8" wide from the 'handle' to about a foot from the limb tips, where it tapered to 1/2" nocks but now there is only about 4" of taper left because I did not adjust the taper as I shortened it because I felt at the time that I would be making my task more complicated if I did. The stave is currently 27#@29", about 23 lbs lighter than I intended but I feel like if I quit now then I'll quit on the next bow too. Your advice and critiques are greatly appreciated.

Thank you,

Aaron
 

[Del the cat]

Looks pretty good , but maybe a tad stiff at the grip* and the outer 1/3rds ?
*depends if you want a working handle... people mean different things by "D" bow...
Del

[ajbruggink]

Yes by D-bow I'm referring to a working grip bow like the medieval English Longbow but tiller examples elsewhere seem to make such bows look like the rounded side of a satellite dish or some similar shape and I'm trying to figure out how I can get there.

[willie]

Aaron

I am tillering a bow very similar to yours in width profile and length, and expecting it to bend through the handle.

it has a straight line thickness taper, such that the tips are 1/2 the thickness at the handle.

its ok to width taper near the tips and bring them around more, but you might want to leave that for last,  after you get the handle bending more.

[Del the cat]

Yes by D-bow I'm referring to a working grip bow like the medieval English Longbow but tiller examples elsewhere seem to make such bows look like the rounded side of a satellite dish or some similar shape and I'm trying to figure out how I can get there.

Ease off the fades/centre/grip thickness, maybe just rounding off the corners will get it moving. If you get your eye up by the grip and look along the limb as you are pulling the rope you'll see if it's flexing. Take it easy as there is a lot of leverage at the grip, and a little bit of extra movement at the grip gives quite a bit of movement at the tips. You'll also feel it in your hand when it starts moving.
The absolute dead centre will still be a tad thicker and it's hard to see the movement right in the middle.
Effectively, it's like bringing the fades in towards the middle more and more until they meet 
When I tiller I tend to get the inner limbs moving first and then move out, nut that's just my preference, there's no "right" or "wrong".
I tend to judge the shape by holding a CD up in front of the picture.
Del

[willie]

Nice explanation, Mr. Cat

[ajbruggink]

Del, when you normally tiller D-bows do take off wood from the handle section right away or do you do it later?

[Dictionary]

Del, when you normally tiller D-bows do take off wood from the handle section right away or do you do it later?

I'll let Del answer, but it is generally suggested to always work the handle in LAST

[ajbruggink]

Thanks, Dictionary

[Del the cat]

Del, when you normally tiller D-bows do take off wood from the handle section right away or do you do it later?

I rough out a bow and put it on the tiller and watch it bend and go from there. So it depends how the roughing out is done!
Unless there is a thickenned grip the bow will flex a bit in the grip. I s'pose it's down to how thick you leave the grip!
My ELBs are roughed out pretty much, parallel for about 16" at the grip then tapering in thickness about 2mm every 6", so the actual grip isn't really thicker than the base of the limbs, no fade no grip so it is bound to move a tad.
It's just personal preference, I put it on the tiller and pull full weight, the middle is pretty much bound to flex first unles the roughing out has been done very close to the line, I s'pose that can happen with board bows and laminates, but with a stave you have to go slower, and with an ELB you need extra tip width to maintain early stablity, so the outers are going to be stiff early on.
We all find our own way of working and seeing what is moving.
This vid shows an ELB first time on the tiller... action on the tiller starts at about 4:10
You can see I get it on the tiller V early when it is V oversize and the outers don't hardly move.
https://www.youtube.com/watch?v=l8OjC7HV4Bk&index=3&list=PLBz2tD9476KQFyMBLEylQGh952tBT_mZB
Del

[Del the cat]

Del, when you normally tiller D-bows do take off wood from the handle section right away or do you do it later?

I'll let Del answer, but it is generally suggested to always work the handle in LAST

Yeah, but does a D bow really have a handle as such or is it all limb....?
Del