Will this be your first bow-making project? If it is, you should definitely, definitely start with something more straightforward.
Now, I know that sounds a bit patronising etc, but bow making is hard work. It's hard enough to take a simple board bow, tiller it properly without coming under weight, not make any mistakes that create weak spots and hinges, not over-stress and chrysal the bow during tillering, and finish the bow professionally and neatly while keeping the bow solid. Add to this the steam recurving you'll need to do, the forms you'll need to build from scratch, the reflex affecting the early draw weight on the tiller, the deflex making the tiller seem uneven on both limbs, and everything in between.... you're asking a lot! You may have noticed that any shops selling archery equipment using The Lord of The Rings name won't be selling recurved bows, just straight D-bows.
However, it can of course be done. The film bows aren't working bows, they're industrial rubber for action shots, and balsa wood/cast plastic for "hero shots" just like any other movie weapon. Weta weren't able to source traditional bowyers for their movies so John Howe had to do the best he could when making up the bows. The design however is solid, and is definitely achievable with enough experience.
The type of bow you're looking at is an r/d or "reflex/deflex" bow, as I'm sure you're aware. If you're starting with a straight stave, you'll need to reflex both limbs out of the centre using steam or dry heat and a form to clamp to. The tips have to be reflexed again, using more heat and different shaped forms. The deflex can either be steamed in, depending on the draw weight you want, or will be bent like that when braced. Look at some Egyptian war bows both unbraced and braced and you'll see how this sort of bow looks when it's not strung.
Something like this:
The reason you should be considering using laminations of horn and sinew is because without these composite materials, the power and performance of the bow will be pretty poor. They're designed to take quite a large draw length, which puts single-stave wood bows under a huge amount of stress. Getting a bow like this from one piece of wood is a hell of a challenge for even a very experienced bowyer. A "normal" draw length for a bow is around 28", while for example a medieval war bow was 32". To achieve a draw length of 32", the bow stave had to be huge, and around 77 - 83 inches long. Hence the draw weights being about
150#@32. Asian bows, and most composite bows have a draw length quite longer, reaching almost 40" in some cases, which is almost impossible with wooden bows.
Here is a fairly accurate Wiki page regarding composite bows
Composite bow - Wikipedia, the free encyclopedia
Composite bows take a very, very long time to make as the sinew and horn can take years to cure properly before the bow can be shot. This obviously is no use to you, if the archery tournament is next year!
I would start simple - make a straightforward board or stave bow without the initial recurves - just to get experience in tillering, working with a drawknife, spokeshave and scrapers. Aim to get a draw weight of around
30#@28. This alone is hard enough when you start, and often you'll come in far too light trying to get the tiller right.
Once you're happy and confident in making straight bows, add recurves to the tips using a form and steaming/boiling/dry heat. This will change the way your tillering is done, as you'll need to decide if your recurved tips will be static or working.
Once you've reached a sensible weight and draw length with recurved bows, try reflexing a stave from the handle. Take a straight stave or even board, reflex the limbs from the fades out of the handle so that tips are 4 - 6 inches higher than when they were straight. Tiller this as a straight bow, and get used to how the initial reflex will deceive your tillering - the initial draw weight will seem massive, and care must be taken not to remove too much wood early on, as you'll end up coming in too light. Once you're happy with recurved limbs, add that final
recurve to the finished bow, re-tiller and you should find yourself with something starting to resemble a mythical / Asian bow.
Don't use yew or Osage to start with - ash, red oak, elm, hazel and other whitewoods are quite capable of achieving a bow like this, and aren't as rare and expensive as something like yew, which is great for a certain type of bow, but would be a waste on something of this design.
Phew.
Hope some of that helps? It could all be rubbish, I'm by NO means an expert. Join some primitive archery sites, read a lot more and you should start to get a good idea of what you're doing. I will recommend a DVD as well - Archery: It's History And Forms by Mike Loades. There's a fantastic chapter on making the composite Asian
recurve/recurve bow, from start to finish (along with an excellent chapter on a yew
longbow/warbow made by Chris Boyton)
Hopefully I haven't put you off - it's daunting, but possible with enough experience. For all I know you guys could be amazing bowyers already and I'm being patronising and assumptive, so I apologise if that's the case.
P.S. You can make a very, very effective bow in this exact style using PVC rather than wood. It's becoming increasingly common now, and there are plenty of YouTube videos on the subject. Good solid draw weights can be achieved, and it's far easier to work PVC than it is wood. And cheaper. Plus, if you struggle with this using wood (and even the most experienced bowyer would!) you might get put off making bows in general which would be a shame, whereas with PVC you'll probably achieve a very satisfactory result without being disappointed and too frustrated.