Primitive Archer
Main Discussion Area => English Warbow => Topic started by: Ruddy Darter on October 01, 2017, 12:17:35 pm
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I got some dimensions worked out for an ash stave, I'm aiming for 120ish at 31 sort of weight. The bow will be 77"-78" in length.
Here's what I scribbled down as an idea (not sure if I'm on the right track) .. I thought I'd run it by you all, any feedback or ideas very much appreciated before I start.
R.D.
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IMO, start 40-42mm wide, you can always take it narrower later.
I like to start oversize and work it down by tillering.
Del
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Thanks Del, to be honest I wouldn't mind it coming out lighter, say 110@31" or even a bit lighter, but I'm not looking for heavier. So I'll go with this if the dimensions and taper read OK. I want to get it worked down thoroughly and smooth rounded before I start to tiller (I'll have to peg in a tiller tree in the garden each time when it comes to it)
I will be lightly toasting it too, from the beginning and when needed, heat gun or butane torch recommended? ( I got both).
Oh, and the finish length will probably be 76"-77" all things considered.
R.D.
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Keep the width the same for at least 6" both sides of center. The dimensions you've marked out will give you slightly too much bend in the handle early on.
Your width and thickness are spot on though, for the weight you're after. If you can, try and get the stave down to exactly those numbers (making the center width the same as I mentioned above), get the stave rounded off nicely and then spend a fair while sighting down each limb in turn from every conceivable angle to mark and remove tiny lumps, swells etc that shouldn't be there - knots and natural movement in the stave taken into account of course!
That should allow you to brace it up almost immediately and see where you're at.
Tiller the whole bow at the same time - don't go for that middle moving, then tips stuff or whatever. Ash will kick you in the teeth at warbow weight if you try it!
Ideally, you want to tiller out to around 25", then do a good, deep heat treatment with the bow clamped flat or with slight reflex (heat gun, not butane torch!!). You want to get the wood so hot that although you're aiming the gun at the belly, the back is too hot to touch, but you don't really want any colour change. It'll need fiddling about with distance from gun to stave to get it right. Then tiller to full draw and do another heat treatment before sealing with epoxy or similar. Danish oil doesn't do anything against moisture, and traditional wax finishes are a pain to upkeep.
76" is a great length for a 31" draw by the way. You could go shorter if you come out too light, but as a starting point it'll work well.
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Great stuff WillS, so good to go...and I'll keep it even for the central 12"', thanks. 8)
I'm aiming to get it worked down smoothly before I start any bend and give it a light toast before I start and concentrate on getting a nice shape on brace, then maybe another light toast when happy and go from there.
Thanks again, I still got to loose a good 5% moisture before I can start so plenty of time to get it worked down nicely.
R.D.
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Have you come across the Norwegian Warbows website? They've got roughing out dimensions for different weights and different woods all in a handy visual format.
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Yes Lucasade, these dimensions are a shimmy around with I think there 160@ width and bearing in mind previous advice about belly depth compared to width for ash worked out what I though the depth should be to corispond with it.
I've only seen generic dimensions on there website, not dimensions for specific wood types though.
I will use Norwegian bows dimensions (very helpful) as they are for the Pacific yew stave I have, when the time comes that is. I'll get my ash staves ready to roll first.
R.D.
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Their dimensions are quite a long way out, from my experience. I've not used them with yew though, but I did try using their measurements when I was starting out on various ash bows and never found them particularly helpful. The guy who put them down on the website is a superb bowyer however (possibly the best heavy bow maker in Scandinavia, along with Eirik Diserud - both who are coming to our camp next year ;) ) so it's a good chance the measurements are for a bow left oversized to be worked down, which is fine for beginners I suppose.
I also think the Norwegian whitewoods those guys use are WAY better than the stuff we're lumped with over here!
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looking at what I assume to be the thicknesses (bottom row), I see a substantial increase in thickness taper rate in the outer 1/2 of the limb, (with an exception in the last 8" or so). Is that fairly typical most warbow designs?
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I used the Norwegian measurements for my hazel and it's about spot on.
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looking at what I assume to be the thicknesses (bottom row), I see a substantial increase in thickness taper rate in the outer 1/2 of the limb, (with an exception in the last 8" or so). Is that fairly typical most warbow designs?
Hi willie,
I don't know if what I came up with for the depth taper is typical of what most ash warbows would be made to, that's why I thought I should check on here, I really don't know enough to say. if it doesn't look quite right when I've got it marked on the stave I'll make some adjustment to it.
R.D.
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I'm also a fan of starting wide and narrowing down. It feels much easier and more natural to me.
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I used the Norwegian measurements for my hazel and it's about spot on.
That's interesting to know. Which weight category did you use, and what did your finished bow end up as?
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Is that fairly typical most warbow designs?
Ruddy, I am not questioning your design, I honestly have no idea about what is typical with most warbows. I quess the tables I see (such as yours and the others mentioned) are always qualified as starting dimensions. It would be interesting to hear from those who have started with such tapers, and have turned them into working profiles. :)
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That's interesting to know. Which weight category did you use, and what did your finished bow end up as?
I used the 100-130lb category, and it's pulling 110lb on the tiller tree at the moment.
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Is that fairly typical most warbow designs?
Ruddy, I am not questioning your design, I honestly have no idea about what is typical with most warbows. I quess the tables I see (such as yours and the others mentioned) are always qualified as starting dimensions. It would be interesting to hear from those who have started with such tapers, and have turned them into working profiles. :)
The dimensions Ruddy has written down are actually perfect for a finished bow with slight elliptical tiller. If you were to make the stave EXACTLY to those numbers, and the timber didn't have any unusual dips, flaws or weird areas of denser wood, then theoretically you wouldn't have to tiller the bow at all.
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I used the 100-130lb category, and it's pulling 110lb on the tiller tree at the moment.
That's great, interested to see where it ends up but looks like you're on the money with that one!
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Interesting thread and dare I say synchronicity, as I will start roughing out ash bow in about hour or so!
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Good going with that FilipT :BB,
R.D.
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Tnx, you too. Today I removed bark and put width dimensions, tomorrow it will got basic roughing out. But I must say wood was cut two days ago so it will be a while since I start to tiller it.
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The dimensions Ruddy has written down are actually perfect for a finished bow with slight elliptical tiller.
That was my guess also, Will. Seems like many warbows are built by first establishing a depth taper and then side tillered to finish, at least more so than than with other type of bows, where most tillering is done on the belly after a width profile is established.
I often see warbow dimensions presented in this tabular form, and presume that many of the mary rose bows measurements are tabulated in the same way? Not having the ability to review these dimensions, or other tables often mentioned by the warbow community, I was curious if the additional thickness tapering in the outers is........ typical, common, uncommon or rare?
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I finished getting the stave worked down to 40mmx30mm ready to start working it to dimensions.
The stave is relatively straight save for a little wiggle inner mid limb. One question I have is the slight D-flex on the limb nearest...would it pay to heat this straight after working it down or would it be more trouble than its worth as it might throw me by creeping back in when I tiller?...would I be better off leaving it alone?
Thanks for any advice,
R.D.
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Heat treating to correct tiller is done once the bow is braced, not before.
Before bracing, you want to try and preempt issues like reflex and deflex. Reflexed areas are left slightly thinner, deflexed areas slightly thicker.
So basically, leave maybe 2mm extra thickness on the belly in that deflexed area, take everything else down to exact finished dimensions and check, check and check again the eyeline, looking for swells, dips etc that shouldn't be there. Get all of those sorted, until you're absolutely sure the bow is ready (I tend to ask myself if I'd sell it and if the answer is yes, it's ready!) and then get the horns on, brace it up and see what's happening.
That's the stage where you bring in the heat gun, charcoal etc to temper the areas that are bending too much at brace height.
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O.K. thanks, I'll just leave it be then...dont want to chance complicating matters,
R.D.
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deflexed areas slightly thicker.
Will, would that mean that you must also leave the thicker area appearing to be stiffer in the bend profile when tillering?
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It also look like I'd be needing to keep it a little stiffer around that area due to a knot (which may be worked out or need a little fill) and that slight wiggle starts just about there.
Something I'll bear in mind, thinking out loud, maybe I'll flip the very tip a little that end with heat to even out if needed, I'll wait and see how it goes.
R.D.
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deflexed areas slightly thicker.
Will, would that mean that you must also leave the thicker area appearing to be stiffer in the bend profile when tillering?
No, they should look like they're bending the same as the rest of the bow. If they're already deflexed they're already essentially bending.
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No, they should look like they're bending the same as the rest of the bow. If they're already deflexed they're already essentially bending.
interesting approach to deflex. Should it look like they're bending the same as the rest of the bow at brace or full draw?
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Just my opinion of course... but:-
NO!
Any features in the unstrung bow should till be evident at full draw to some extent, so a limb that has a little reflex (unstrung) should appear a tad stiff at full draw. A limb with slight deflex should appear a little weak at FD.
If you thin down the reflexed limb and leave the deflexed limb stiff, you will end up with a bow that looks perfect for five minutes until the reflexed limb starts to go even weaker, then chrysal and collapse.
Del
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Just my opinion of course... but:-
NO!
Any features in the unstrung bow should till be evident at full draw to some extent, so a limb that has a little reflex (unstrung) should appear a tad stiff at full draw. A limb with slight deflex should appear a little weak at FD.
If you thin down the reflexed limb and leave the deflexed limb stiff, you will end up with a bow that looks perfect for five minutes until the reflexed limb starts to go even weaker, then chrysal and collapse.
Del
Yup :)
You are trying to make the strain even along the limb. Regardless of what the limb is doing it needs to feel even strain at full draw.....or else problems are round the corner!
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Yeah. Basically that.
With RD's ash stave, the "deflex" is so minimal that it'll probably disappear once the stave is shaped and bent a few times, so won't really be an issue. It's the more apparent reflex/deflex areas that need thinking about.
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In bowbulding, generally I have found it well worth the effort to be quite particular about establishing a constant the thickness taper, only making local adjustments later in the tillering process. Of course, that might not be the only way.
I presume that many of the Mary Rose bows were measured and the dimensions published? Does anyone know where some of these dimensions could be viewed?
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In a book called "Weapons of Warre". I have been told that it has really good and extensive info, but its a bit pricey. It will be a while till I can afford it.
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thanks Filip,
a search of this site brought up an interesting thread with some dimensions
http://www.primitivearcher.com/smf/index.php?topic=26580.0
I plotted some of the data Craig averaged
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An old post, but managed to get a start with these dimensions, pulling to 25" it's hitting 90lbs. It would of been a fair bit more but for a soft spot mid lower limb so had to take off quite a bit upper limb to even out. Just going to round the edges on the bottom limb a little more and then going to hit the belly with some heat as suggested before I go any further, it's taken an inch of set, mainly bottom limb where it's been kept squarer while I've got the top limb bending more, will the heat treating help reduce set? (I managed some side nocks :D)
R.D.
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Looking good... Left tip seems to be bending a lot, but it could be an optical illusion due to the abrupt change in lighting/background.
Del
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Thanks Del, It's a bit of both I think, it does bend a bit too much there, I'm going to round the edges outer mid limb just before it which hopefully will even it out. The tiller needs some tinkering in places but I'm going to hit the belly with some heat and see how it looks after that. I'm quite interested to see if or how much the heat will alter the draw weight as it stands now.
Anyway, I really posted to show how I got on with these dimensions, they are pretty much on the mark for what I wanted although I would add a mm or so to the limb tips, last 10" give or take, depth mainly, as the tips could of done with being a tadge stiffer as it stands.
R.D.
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My current philosophy is to accept a 'warts and all' tiller that reflects the natural reflexes and deflexes in a stave which is what Del is saying!
Now I know Del does not like the 'by the numbers' roughing out and get it braced method that Will described, but this is what I favour, in order to have the knowledge that 'in theory' at least, the limbs will be evenly stressed when bent!
Now I know some times a stave displays a reluctance to bend in one area or seems to be weak and bends to much in another but that can be addressed when you are secure in the knowledge that the tapers are even and it's not due to a reflex or deflex in that area.
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Thanks for that meanewood, that's very helpful as this stave is slightly deflex lower limb and reflex upper limb, with the lower limb readily wanting to bend a lot more. This was also compounded to a degree by a little snake in the mid lower limb which I followed a bit too well and perhaps I could of left a little more wood there. Still, I feel I learned some key points to pay more attention to when working a stave before getting it on the tiller.
R.D.
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Here's where I am after some work and a light heating of the belly , a pic of the bow braced, drawn to 30" and then unbraced. It's hitting 100lbs at 30". I'm going to fine sand and then give it another blast with heat, and I think it needs a little off mid-inner limbs. A better place to finish this post and I'll enjoy the next jaunt at bow making alot more with what I learned with this effort. :) Thanks for the help and advice.
The bow is 77&1/2" nock to nock.
R.D.
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It does look like there is a hinge near the tip on the left limb, but nice all the same.