Tiller tips...

[WillS]

Trying to get this yew warbow up to brace height and it's kicking me in the arse.  One limb was reflexed (I seem to keep coming across these uneven reflexes!?) so it's throwing my perspective out.  As far as I can tell, right limb is stiff.  Right?



Is it just as simple as bringing that right tip round more?  I don't really wanna play with the tips until I'm much closer to finishing.

[Del the cat]

You are not flexing it enough to see, and I don't think you have enough poundage on it to see.
You need to apply at least the target draw weight to see what's happening (obviously stop, if there is any sign of anything nasty happening).
The tips have to come back about 6" to let you see some shape, and on a long string that will take at least the target draw weight.
Check out my blog where I'm tillering a 130# warbow.... it took about 140# on a long string to get it back far enough to brace at 4", but once braced, it came back 19" at 120#, so you can see it takes a lot of long string weight to simulate the braced string.
http://bowyersdiary.blogspot.co.uk/2013/11/warbow-tillering-120-5-brace.html
Del

[WillS]

I'll try and get a pic tomorrow then of it sat with 120lbs on it.  I've taken it up to that point already (130 is the target weight) 

I'm slightly concerned with how much set the left limb is taking already, and really wanna get the right limb moving to ease the stress off the left.

[Del the cat]

I'll try and get a pic tomorrow then of it sat with 120lbs on it.  I've taken it up to that point already (130 is the target weight) 

I'm slightly concerned with how much set the left limb is taking already, and really wanna get the right limb moving to ease the stress off the left.

That sounds, like you've answered your own question .
It often works like that, by the time you've taken the time to take pics and post then you've decided on the course of action anyway... that's the main reason I do my blog.
Del
(I was reluctant to comment on the actual tiller 'cos it's so hard to see from the pic. Possibly the lighting, but the right limb looks a lot skinnier, and of course I dunno what it looks like unstrung.)

[WillS]

Unstrung it's basically straight, with this great flip of reflex starting about 8 inches from the right tip.  Tricky!

The right limb does look skinny, I've been trying to avoid overdoing it, but with all that reflex it just isn't moving at all.  Dreading the thought of reducing enough to get it moving and then finding out it's way underweight!  I've done that too often, but can't seem to beat my brain into getting over the issue.

[WillS]

As a reference (to myself as much as anybody reading!) I'll stick the dimensions in here as well.

Measurements taken from centre, and every 6 inches outwards

Right Limb (in mm) - Reflexed limb

W     /     D

40          36

39          33

39          31

36          30.5

33          26

29.5       25

23          26

18          25   (leaving tips wide and thick so far)


Left Limb

W    /    D

40         36

40         33

38         33

35         31

30         28

28         26

23         26

18         25

[toomanyknots]

Unstrung it's basically straight, with this great flip of reflex starting about 8 inches from the right tip.  Tricky!

The right limb does look skinny, I've been trying to avoid overdoing it, but with all that reflex it just isn't moving at all.  Dreading the thought of reducing enough to get it moving and then finding out it's way underweight!  I've done that too often, but can't seem to beat my brain into getting over the issue.

I do think you should bring the right limb around to meet the left limb. Typically the left limb will be stronger, and will be your bottom limb, and the reflexed limb will be your weaker top limb, if the bow is tillered a normal tiller. You typically won't have to add any positive tiller with ones like this, because the straight limb will be naturally stronger than the reflexed limb, if tillered even to the eye. The left limb will end up being bigger than the right reflexed limb. The important thing is the tiller.

[WillS]

Video!  Hopefully this works.

The brace height is zero, so the string is tight but not bracing the bow at this point.  It's being winched down to 120lbs, which takes it to roughly 15 inches I think. 

I still think it's the right limb (with the reflex) that's causing the uneven tiller, but what's weird is when paused at full draw, both limbs look even, but not the same if that makes sense.  It looks REALLY ugly when you flip it horizontally though. 

May be worth bearing in mind this is currently 83.5 inches long, which is way too big, so I've got room to chop ends off and sort that out.  That should help with the really reflexed tip on the right, albeit losing some nice snappy kick.... dilemma!

Advice, thoughts, etc etc would all be appreciated!  Cheers guys!  (click on the picture I think, to see the video)

[Del the cat]

Looks pretty good to me .
The tips move about 3 bricks max. Which is enough to get a braced string on it.
I think you really need the short string on it as it will change the angles and the tiller slightly.
I certainly wouldn't take off any more until you have it at say 4-5" brace. Then slowly take it back to target weight (with fingers crossed etc )
Del
(Prob with reflex is you can take so much off trying to bring it round it ends up weak. So I wouldn't worry if the reflex limb looks a tad strong... the unbraced shape should be still showing at full draw)

[WillS]

Thanks Del! I'll get it braced up and work on it properly tomorrow.  It's eating my Fastflight string like crazy at the moment which I've not come across before.  I'm using the string I've got on it for long string tillering, twisting it up to get it the right length to brace and it's just stretching out like mad, so the brace height drops right down to nothing instantly.  Really odd!  You'd have thought a string that's been taken up to 120lbs during tillering would be fully stretched?!

[Del the cat]

Thanks Del! I'll get it braced up and work on it properly tomorrow.  It's eating my Fastflight string like crazy at the moment which I've not come across before.  I'm using the string I've got on it for long string tillering, twisting it up to get it the right length to brace and it's just stretching out like mad, so the brace height drops right down to nothing instantly.  Really odd!  You'd have thought a string that's been taken up to 120lbs during tillering would be fully stretched?!

Yeah it's that string angle thing again... even my Angel Majest stretches out a bit. Gotta remember the difference in string length between say a 4" brace and no brace is prob' 1/4" and 1/4" on a string that's 76" long is ... hang on let's get the clculator up... yes... it's b*gger all percent 
Del

[toomanyknots]

My personal opinion is that you could reduce it in weight a bit if 130 is your goal, especially at 83" as if you need to up the weight in the end you could pike up to 5 inches off the bow and still be roughly good on length. I know only full brace is gonna tell the truth regarding draw weight, but I still think it would help in keeping stress low on the bow, over stressing it and then reducing weight will always cause more set of course, but at the same time I know some amount of this is unavoidable. I also think, at the same time you do that, you could pull it a bit farther, the bend is looking pretty good to me. But I think you could tiller a bit more before brace. I think, using the shortest string possible of course, pulling and perfecting the tiller early on before brace can help reduce set and minimize the stress the belly is gonna take at brace. Just my own thoughts,  .

[WillS]

Cheers fellas!  I'll tidy up the bend on the right a bit and get it to a 2" brace or thereabouts then see where I am!

[1442]

here's a little trick I use on flat bows to get smooth matching bends in limbs of different side profiles.  Just take a straight edge and draw a perfectly straight line on the side of the limbs. The line may not be able to go the length of the limb because it will run off somewhere due to the limb not straight enough but position the line so that it will span the reflexed area well and then another line can be drawn perfectly straight on the rest of the limb.  When the bow is drawn on the tiller tree or whatever you can look at the lines to match the bend of the lines on each end which is easier to see exactly how even the bend is than trying to match two limbs that are differant.
This should work really good on warbows due to the thickness of the limbs having much more area to get a straight line on. Flat bow limbs are so thin that the straight lines run off the bow in a short section if the side profile wiggles much, but even a short line through a wiggle will show exactly how much the wiggle area is bending.
This also works great through the handle area and will really help identify how much bend is happening through or right out of the handle area through the fades.
This may help you see how even the actual bend in the outer limbs are. I have a pic i can post this evening of the process on a flat bow if my description here is not clear.
Goodluck with the bow !       Terry

[WillS]

Thanks Terry! Appreciate the help! I'd heard of the technique but never tried it.  Might give it a go if the reflex limb keeps tricking my eyes!