Primitive Archer
Main Discussion Area => English Warbow => Topic started by: Redhawke on January 12, 2019, 05:10:29 pm
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I am building a tri-laminate English Warbow that will be around 80", draw between 100-120lbs at 32" draw. I have Ipe for core and Yellowheart for the belly wood. What would be the best backing material for this bow ? I have been thinking Hickory but can't seem to find a piece that is quartsawn so am leaning toward Hard Maple now but really unsure. Idea and suggestions are most welcome and appreciated. (W )F(
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My experience is with hickory and bamboo. If you can get your hands on hickory I would as those are stiff belly woods that hickory can for sure handle. If you can get bamboo that would also be excellent. But I've heard well of hard maple as a backing and it's a similar density to hickory so that should work just be very picky with grain. Hopefully someone with more backing experience speaks up.
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I finally gave up on the quartersawn hickory. I can't find a source that has anything 80". I did find a place that sells bamboo planks and have 6 of those on the way so the backing issue is solved I hope.
Thanks for the help peacefullymadewarbows.
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No problem. Do the bamboo planks have the crown from the outside of the plant intact? The nodes of bamboo are like knots in a stave and should be left proud.
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They are supposed to but should arrive tomorrow so I can take a look then and let you know. I'm still trying to wrap my head around tapering the laminates so they all end together after reduction on the end. WoW.
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Yeah that can be intimidating. I tend to only taper the center lam. I leave the back and belly parallel. The belly tapers naturally during tillering. But I also don't glue in reflex. I've seen people taper lams and almost pre tiller them so the reflex glues in a nice shape. I made a tapering jig just by sawing a gentle straight line slant on a piece of 4x4. I send them through the planer. I had did a 1/4" center 1/8" tip ratio for my core and it turned out perfect at the tips in terms of having everybody in the horn tip.
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Yes, the bamboo arrived with the nodes intact and looking great. Each plank is almost 1/2" thick so I'm guessing I will need to thin that down considerably. On the core of Ipe do I taper both faces or just the face that will be facing the belly ?
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Sounds like you got great boo. I just taper one face. Just make sure you have good even clamping pressure so you don't have glue gaps and you should be golden.
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IMO, I think you would be better served to use the ipe for the belly and the yellow heart for the core. Ipe is very strong in compression. I know the color combo would probably look better with the darker wood as the core but I'd be more interested in performance than beauty...not that it would be not beautiful either way.
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Pat B, I actually intend to stain the Bamboo with brown leather dye which will give it a reddish cast. Yes, dealing with these beautiful exotic hardwoods I have to remind myself it's not an art project the performance should in fact come first. My original plan was to use the Ipe as the belly wood but I only see it used as a core wood on tri-laminates so far. I thought the color scheme would be dramatic to the eye so that option remains on the table. I have been thinking about the bamboo a bit and would like to know what a good nominal thickness would be for that layer. It's coming in at around 1/2" at the end of the planks. I'm a bit worried that it's too thick but can't find a reference anywhere for the poundage I'm attempting to obtain at end of build. (W
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IMO, I think you would be better served to use the ipe for the belly and the yellow heart for the core. Ipe is very strong in compression. I know the color combo would probably look better with the darker wood as the core but I'd be more interested in performance than beauty...not that it would be not beautiful either way.
+1
The core does less work than the back or belly, so it wants to just be stable and light.
The middle lamb should be tapered, but just taper one face... the angle is so slight it's not worth trying to taper bathe faces. At the centre where the two tapers meet it will give a V slight raised pint, this can just be sanded to flatten it or blend it to a gentle even curve so the belly lam will glue down well.
Del
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Bamboo backing is very thin. Approximately 1/8" in the handle and tapering to 1/16" at the tips. If you are making a wide bow it may be thicker depending on the original diameter of the bamboo log.
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I like Yellowheart but I would use the Ipe for the belly as well. For an 80" bow pulling over 100# I would use a Bamboo backing a bit thicker than 1/8" thick. Quite frankly I would make the bow somewhat shorter than 80", unless you are making a bow that will pull well over 32" of draw. I also find that Maple is a better backing material than Hickory
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I like Yellowheart but I would use the Ipe for the belly as well. For an 80" bow pulling over 100# I would use a Bamboo backing a bit thicker than 1/8" thick. Quite frankly I would make the bow somewhat shorter than 80", unless you are making a bow that will pull well over 32" of draw. I also find that Maple is a better backing material than Hickory
Marc St Louis the young man this bow is intended for has a 32" draw to his anchor point. My thinking has been that the longer bow would make the (for me at least) high draw weight easier to for him to handle, he is 6'2" tall. How long for the given draw weight and his height do you think would be appropriate ?
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Personally I would go with a bow around 75" in length
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Thanks everyone for helping with this project, it's intimidating to say the least. The plan as of now is to build the bow with Ipe belly, Yellowheart core, Bamboo backing, finished length at 75". I did find plans for an excellent tapering jig from Paul Sellers on YouTube for using hand planes so that concern has been addressed. My next question is how to calculate laminate thickness for the given draw weight and length ? Is there a formula or method that is used ? Also the starting thickness for the core and the taper to thickness.
Thanks again to each of you for sharing your knowledge.
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A couple of things that may help.
1. If you are aiming for 65"... make it 67" to allow a better glue up of the tips and potential for taking an inch off each end to adjust tiller, the poundage or to shift the centre line etc.
2. A linear taper in the core is good, but bear in mind the finished bow isn't a linear taper. The taper increases in the outer 1/3
3. You won't get spot on dimensions for glue up, you'll still need to be tillering, so don't make the belly lam too thin.
I've not done that wood combo, so I can't give figures for thickness... I could make an educated guess if you like! :) ::)
Del
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Del the cat, that would be extremely appreciated. Yes, after reading several follow alongs on this site I understand the belly should be thicker and thinned during tiller. This is so much different than flat bows.
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I have a 76.5" ntn Hickory backed Yew 80# @ 32" ELB/Warbow.
If you maybe take the thickness figures and use them as thickness of core + belly lam (e.g without the boo).
That should give you plenty of poundage when you add the bamboo back :)
Upper limb is 37" from arrow pass to top nock.
Distance from arrow pass. Width (mm) . Thickness(mm)
0 (at arrow pass) 32.8 27
6" 33.2 23.5
12" 31.1 21.8
18" 30.8 21.4
24" 28.4 19.9
30" 24.9 17.7
36" 19.9 14.4
39" (nock) 13 11.9
Note:- I mix inches and mm 'cos inches are more suitable for distances along the limb but mm are very convenient for width and thickness.
Hope this makes sense and is of some use.
Del
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Del the cat, it makes perfect sense sir. I want a finished length of 75" so start at 77" and work from that point. I suppose my real question is what thickness should the Yellowheart core lam start at and the end of it be tapered to for finish (or a rough guess)? The Ipe can be added to the equation to meet depth requirements and meet the 100-120 lbs draw weight. I totally agree that mm are easier to work with in many instances. I build cigar box guitars and use mm almost exclusively on those builds.
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Del the cat, it makes perfect sense sir. I want a finished length of 75" so start at 77" and work from that point. I suppose my real question is what thickness should the Yellowheart core lam start at and the end of it be tapered to for finish (or a rough guess)? The Ipe can be added to the equation to meet depth requirements and meet the 100-120 lbs draw weight. I totally agree that mm are easier to work with in many instances. I build cigar box guitars and use mm almost exclusively on those builds.
Depends on what thicknesses of wood you have available... but...
If it was me I'd make the core a linear taper from about 12mm to 3mm (or maybe 13 - 3) that seems to be manageable dimensions that will still leave plenty of belly wood to tiller. :)
I reckon on a roughing out taper of between 1.6mm every 6" to 2mm every 6"
Maybe if you taper the core from a little bit thicker (say 14mm) that would allow you to flatten/blend the centre to a flatter, more gentle curve where the two tapers meet, that will make it easier to glue on the belly lam.
Hope that's some help.
Del
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Del the cat, it helps tremendously. If all goes well I will try to get the lumber ripped into dimension this afternoon. I'm a bit anxious to see how my Freud thin kerf ripping blade fairs on the Ipe and Yellowheart. If all goes well my next step will be to build a tapering jig for the core laminate but that will be a day off project. Thanks so very much Del the cat and all you guys for helping me with this project. I'm unsure if I'm equal to this task and if it were not for such a very special young man I wouldn't even consider trying to build it. I will do my best to add pictures as I go along with the build and I'm sure there will be lots more questions coming from me soon. Many thanks.
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Del the cat getting close to glue up time for this bow. Do you think I should make a former and add a bit of reflex on this build ? If so how much should I go for and is there a tutorial here for building one ? Thanks again sir, all the help here has been a tremendous help.
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Personally I wouldn't add reflex to a heavy long draw bow as they are a pig to get to brace anyway, and reflex will make it want to flip on the tiller. If you really want to, then I'd say no more than an inch.
Del
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That makes sense to me sir and I will not do it. Thanks again.
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Getting ready for glue up if I can get a nice dry day. Yellowheart core is tapered, bamboo backing flat and thinned. Just got to think about ripping Ipa or leaving it whole. It's a full 1 inch thick. Tried to add photos but made file too large.
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I will try this again, here are the pictures of the Bamboo that has been thinned and flattened. The Yellowheart core tapered from center to end, and the Ipa belly wood.
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The Bamboo flattening.
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Bamboo profile.
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All 3 lams spread out a bit.
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I'd suggest you pre-shape the lams before glue up or the tips will be too thick. Getting the tip shaped ahead of glue up will prevent this. You can leave the handle area full width for now and this will give you a place to clamp the bow while tillering.
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Oh my, just walk inside from gluing it all together. Wish me luck. )-w(
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You'll probably just loose the belly wood at the tips but the tips are non-working anyway so it will be a cosmetic problem.