Tillering warbow with reflex

[WillS]

I'm about to start tillering a new ash warbow I'm working on, but the stave has about 2 - 3 inches of natural reflex in the lower limb. 

I'm shooting for 100# @ 32", as the ash is incredible quality.  I've made it as wide as possible and a very shallow D profile to counter the possibility of set and chrysals that ash seems so prone to.

The trouble I'm finding is that with the roughed out bow being so large already (40mm wide in the handle by 32mm thick) and with so much reflex, the early draw weight is immense, which is making gauging the tiller pretty tricky.

Is there a technique or method for tillering heavy bows with uneven reflex?  I'm tempted to start reducing the thickness on the reflexed limb to bring it round equally to the upper limb, but I'm sure that will backfire during the later stages of tillering and leave with me a lighter than desired bow.

[RyanY]

Best advice I'd give is to get a really good bend while floor tillering and get the limbs as even strength as you can judge so you can get it braced early. Using a long string to tiller a bow with reflex usually causes it to flip over so getting it to any brace would prevent that. Draw weight won't change very much between a low and high brace so just focus on good tiller.

[WillS]

Thanks! Does floor tillering work for heavy bows? When I try, nothing moves haha!

[RyanY]

Yep! Gotta put your weight into it. It helps to use a mirror set up against a wall and on the floor so you can look at it directly through the reflection while putting your body into it. If you have a warbow that's finished push that against the floor to see how it feels.

[Del the cat]

Its a pig if the limbs are V uneven.
IMO DON'T 'weaken' one limb to bring it round else you'll find the draw weight has dropped too much on that limb.
Reflexed staves are V tricky too as they will try and flip on you until you get somewhere near brace (pig to string with a short string too).
It is also easy to take off too much weight on a long string just getting back to brace.
A couple of thought/ideas.
Get the bow on the tiller with the tips lining up horzontal rather than the grip. Is it possible to draw a straight pencil line along the side of the bow and use that to look at rather the limb?
Maybe it's one time where clamping the bow to the rig may help observe the individual limbs and stop it flipping in the early stages?
When in doubt step away and have a cuppa. V long bows and bows with reflex can seem V high poundage and then melt away before your eyes to a feeble bow... Ok a slight exag' but you get the drift.
Del

[WillS]

Cheers Del.  I actually tiller upside down, with the string anchored at the top, and the tillering rope pulling the handle down.  It seems to make life easier (on straight staves..!)

I'll have a crack at tilting it, so the tips are lined up regardless of the handle and see if makes visualising it a bit easier. 

S'awkward though, with it being ash.  I'm used to having proper D-section profiles for longbows, which doesn't work with ash.  It makes removing small amounts of belly wood but keeping an even keel and rounded edges quite tricky.  I can see myself taking too much off very easily. 

This is going to require a LOT of tea.

[adb]

I've found tillering heavy war bows with reflex to be very challenging. Tillering a stave with reflex in one limb would be even more tricky. I think you might have trouble with the reflexed limb wanting to roll over at low brace. Getting it to full brace and making weight will be tricky! Once you get it bending, it'll be better, but getting it there is going to be a challenge. Watch you don't get the stave banding too much in the middle too early. Can you heat correct both limbs first, so they're more even? That's what I'd do. Good luck!

[WillS]

Thanks Adam.  It's definitely trying to flip on me!  I had to abandon tillering for a bit as it just wasn't behaving.  I went back to floor tillering it and really leaning into the thing but it's a bit of a monster.

My worry at the moment is that the last 8 inches or so are thin enough to bend quite comfortably, while the rest of the stave is far chunkier AND reflexed, so I'm in real danger of inducing far too much strain on the tips before the rest of the bow starts to move the way it should.   This has taught me to keep the last third pretty heavy on a stave like this. 

I'm toying with the idea of heat treating, as it will certainly help overall.  I had wanted to finish this bow without using any heat though, as all my other bows had to be subjected to so much dry heat and steaming that it would have been really nice to avoid all that.  Of course, if we all got what we wanted when making bows it would be pretty boring...

I'll keep you guys up to date with this, and hopefully have some pics to show what I'm working with at some point.  Thanks for all the pointers already!

[Del the cat]

Steam is (IMO) a lot gentler on the wood than dry heat. May be worth investing in a cheapo wallpaper steamer and finding some offcuts of insulation board etc.
Gotta admit that getting the two limbs to match will make it much easier to tiller.
Keeps some width on those tip too to allow for any string line adjustment.
I tend to tille rfrom the middle out... but that's just the slightest flexing near the middle whilst exercising it at full draw weight and watching it up close (not easy on a big warbow)
Good luck!
Del

[WillS]

Right, got some pics for anybody who's up for offering some tips!  I've put it on the tiller upside down (to me!) because I think most of you tiller this way, so hopefully that's easier to visualise for you.

First pic is the bow under no tension and second is under about 50lbs, or just enough to get the tips moving.

My worry at the moment is that deflex area on the right limb.  To my inexperienced eyes, that screams "hinge" but as it's deflexed without any tension, do I still treat it as a hinge?

Basically, where would you guys go from here?  This is kicking my ass at the moment, as I'm aiming higher than I have before, and the stave is a tricky one as well.  Heat treating isn't out of the question yet, so if that's the best advice then of course I'll do that.  But I'd rather not!

[Del the cat]

Where would I go from here?
Pile on the draw weight!
The bend in the right limb is just what was there initially.
Look at it this way... If you intend to pull it to 100# you will do less harm pulling it to 100# now, where the deflection will be less and the potential for a hinge less. Than if you remove wood, making it thinner and weaker and then expecting it to withstand 100# !
I'm not saying yank it right back to 100# without watching it, but winch it 60# 70# 80# etc keeping an eye on it.
It's just gotta be done, also bear in mind 100# on the long string at a tip deltlection of say 3 or 4" isn't going to overstrain it, as 100# on a long string is about 75-80# braced.
I'd aim to see some slight movement near the middle and a reasonably symetrical tip movement at a long string 100#
If you can get that, then you can breathe a sigh of relief knowing it's taken 100# and you are well on the way to just slowly teasing it back.
Better to see what it will do know than pussy foot around too much and risk coming in under weight.
Other opinions are doubtless also available.
Del
(BTW When piling on the weight, check there is no one standing behind you with a paper bag!)

[adb]

Most of the reflex appears to be in the middle. I usually get the middle moving first anyway. As Del suggests, give it a tug to 70 or 80#, and see what it looks like. Dealing with this is no different... remove wood where it's not bending enough, and leave it alone where it's bending too much. That being said, you're going to want to leave the right tip alone. Try and get rid of the long string asap, and get it to low brace. Those reflexed/deflexed limbs will fool you with too much time on the long string.

This is going to be tricky, but get the middle moving first.

[Del the cat]

If you realy feel you must remove weight take a tad off the left.
If you really study it, the right limb hasn't actuallt moved but the left has pulled down by about the same amount as it's thikness. Now this is probably due to the left being stiff and pulling down see saw satyle nad flexing the right.
Bottom line.. there isn't enough deflection to really see what's happening so pile on the weight!
Del

[WillS]

Eeep.  So there's no risk of causing set in that right outer third?  Everything's telling me that the first thing I should do is remove wood on the right inner third to relieve the outer, before continuing. 

[Del the cat]

Get the two pics on the desktop and flip between one and t'other to see where the band really is.
I don't think it's right outer limb.
I've just done it, and I reckon it looks like the bend is actually in the middle to inner of each limb.
Look here, I've turned it into a video.
http://s411.photobucket.com/user/Del_the_Cat/media/websitevideos/tiller_zps735507b3.mp4.html
Wierd thing is the right tip is LESS deflexed under load!!!
You can see the value of having a fixed camera position. It would prob be more obvious with less dwell on each pic and a solid camera pos'
Tell us what you see!
Del