Tiller help please

[stuckinthemud]

Ok, deep breath, crossbow lath mk4. Character yew stick, well above target weight, still on long string (hanging down 3inches).  Theres a few swoops and hollows but only one I'm really worried about. Lots of knots to keep things interesting. I've reached brace height bur not braced it yet, I suspect the outer thirds are too stiff but am unsure what to do with the big hollow  as it has quite a steep curve.  No set yet, and the stick is still a bit reflexed but the shape is all over the place. Would you heat it straight?

[stuckinthemud]

Ok, so I reduced the outer thirds quite a lot,  now am just above target weight and at full draw on a long string tight to the belly.  Still no set, still about an inch of reflex. Thoughts? Would you string it now?

[DC]

Tillering advice for something like this is out of my league but I would like to see some padding or something where the prod is sitting on that pin. Yew is awfully soft compared to some. That could lead to a dent that could weaken it substantially.

[stuckinthemud]

never thought to pad the pin, haven't bruised anything on it yet but it seems like a good idea, will definitely add some kind of leather wrap, thanks 

[Del the cat]

It's so wibbly wobbly (olde English bowyer's term ) that it's very difficult to judge anything yet, I'd just say, go over it very carefully with fingers, eyes, verniers to try and check that there are no thin points, abrupt changes in thickness or over thickpoints.
I think you'd be better off with some cleaner rwood.
What's the overall length that you want? I'll see if I have some off-cuts or laminations or stuff that might help you out (can't promise anything)
Del

[stuckinthemud]

Thought I'd use Del's trick and wind the long string through a ring to brace it instead of making up a string. Step on to string it? No chance, get it on the scales, 60lb of effort to get it to brace. Target weight is 45lb at full draw....

[bownarra]

If your target weight is 45# don't pull it more than 45#.
A 45# yew bow of that short a length won't have much wood in it. As you shorten a bow it get stiffer Hard to tell from the photos but it looks afwul thick to me.
Also the peg should be replaced with a piece of wood(padded) that is the same width as your stocks end.

[stuckinthemud]

Thanks, I'll thin it down some, one of the reasons I avoided yew to start with was I didn't want a toothpick for a lath but then again the reason I took the sapwood down to 2mm was because I figured this was likely to happen.

Really struggling with the whole don't draw past target weight thing, I've developed the habit of getting to low brace and seeing where I am but as I get better at floor tiller, my brace height draw weights have gone up amd up; my first many bows were sub 30# at brace that doesn't happen too often amy more but now its all going wrong as I try to get the weight down.

Currently 18mm thick at centre, 14mm at limb centre, 9mm thick at tip

[Del the cat]

I've got some of fast grow Walnut that had no heartwood!! (see link at the end) I have several staves and one off-cut that might do you 40" long 43mm wide and plenty thick enough. I could rough the thickness down to some sort of taper if you want to get it about right.
It's cut with the grain running ||||||| but the rings are V coarse.
I also have some Ash backing that is sawn the same way.
Let me know if you want it and I can post it to you.
https://bowyersdiary.blogspot.com/2020/01/the-curious-case-of-heartless-walnut.html
Del

[stuckinthemud]

Del, that is immensely generous, thank you, I'll be in touch.

[PatM]

I wouldn't anything but a prime stave, preferably backed,   held anywhere near my face at full draw for a long period.

[stuckinthemud]

Ok, so several mm later I am close to target draw weight but will probably do a light heat temper.  My question is, how much further should the left limb (upper in the photo)  come around, how much should the final tiller reflect that hollow/step in the limb?

[stuckinthemud]

Right, so, tested it a bit, it has taken virtually no set though there's a bit of string follow 6 inches from each tip but that disapears over night. Even though draw weight is where I want it, normally I wouldn't hesitate to heat temper but with so much character should I do  a light temper rhis time?

[mmattockx]

So, I figured I would ask if this is going on an existing crossbow stock or if you are making that as well? Will we see pics of the final product?


Mark

[stuckinthemud]

Its an on going project, I've made the stock though if this lath makes it then the stock will need to be shortened to match it. Once everything's finished I'll definitely  post some photos