Bow from only bamboo?

[TLM]

With self bows the theory simplifies a lot ...

With bamboo's density something like sandwich cross section probably would be closer to optimum.

 

[SCOMAN]

See post #6

You’re good. My scanning of posts....not so much.;-}

 

[Cikoun]

Hello and welcome to the forum.

Ignore Erbswurst

While there are some archers and bowyers here, I think you will make more progress with a dedicated archery forum. There was recently a thread that talked quite a lot about bow making and information resources.

Tool Kit - What do I need in it?

My current practical history question is what did Native Americans use... my guess would be stone tools (scrapers) -- iirc there's a Ray Meade episode where they build a longbow with stone tools and folks have been making copies of "Otzi's) bow using the tools he carried...

bushcraftuk.com

There are links to some really good dedicated bow forums in the thread above.

Wayne, one of the other moderators here teaches building bows from bamboo at our summer Moot gathering. Another Mod put together an article for his Blog - building a bhutanese bow

How To…. Build a Bhutanese Bow

Back in August of 2012 at the BCUK Bushmoot I learnt how to make a Bhutanese Bow with Wayne Jones of Forest Knights. As far as I know Wayne is the only instructor in the UK running classes in …

www.bushcraftdays.com

You can get away with a lot of board imperfections if you glue a backing material to the wood. One of the best is linen in its raw fibre form, but you can use linen cloth. You can find threads about linen backing board bows. You can use other things to back bows, like rawhide, and bamboo, although bamboo is so strong in tension that it can cause the belly wood side to crush, so not recommended just yet.

Thank you very much for the help, I really appreciate it a lot

 

[C_Claycomb]

And yet we made very serviceable and fun bamboo bows when we were kids in North Africa without any of the theory. I'm talking real bamboo mind, more like small tree trunks than canes (50mm to 75mm diameter). No science, no modulus of elasticity, no worries about stress or strain - just have a go and enjoy it. It's horrible stuff to work though and we had loads of cuts from the edges.

OK, to be fair we were shown how to do it by the Arab kids, who no doubt learnt it from their fathers, but there was no 'exactness' to it and they were very useable bows. There are loads of Youtube videos that will show you a variety of ways - from the simple to the complex. It's not at all difficult to get a 20lb+ bow with the right material though the faster ones were usually heat treated.

Edit: I should confess, I haven't made a bamboo bow for a very long time mind; we just can't get that quality of material here.

Do you know where the bamboo came from and what it was used for? It isn't something I associate with North Africa.

I have had a 70mm bamboo log, about six feet long, split in half, in a corner of my shed for about 12 years. It was bought from a garden centre with the intention of using as backing with some hickory I bought. Never got around to it. I love wood work, and enjoy bow building, but the splintery nature of bamboo kind of put me off. I have never seen material that size for sale again. I know that Wayne buys his specially from somewhere that imports it themselves. Material scarcity always makes me cautious about jumping in without a detailed plan.

What do folk think about the other question, buying boards unseen and hoping they are bow suitable? I have always been able to pick my boards and have it in mind that this is important. Maybe if the aim is just 30lb and one can back and/or go wider it isn't so much of a risk? Thoughts?

 

[Erbswurst]

That's an international bamboo bow conspiracy here.

 

[Broch]

Do you know where the bamboo came from and what it was used for? It isn't something I associate with North Africa.

I have had a 70mm bamboo log, about six feet long, split in half, in a corner of my shed for about 12 years. It was bought from a garden centre with the intention of using as backing with some hickory I bought. Never got around to it. I love wood work, and enjoy bow building, but the splintery nature of bamboo kind of put me off. I have never seen material that size for sale again. I know that Wayne buys his specially from somewhere that imports it themselves. Material scarcity always makes me cautious about jumping in without a detailed plan.

What do folk think about the other question, buying boards unseen and hoping they are bow suitable? I have always been able to pick my boards and have it in mind that this is important. Maybe if the aim is just 30lb and one can back and/or go wider it isn't so much of a risk? Thoughts?

Oh it was very definitely native! It grew along dried stream beds and field edges. The locals used it as fuel as well as making mats and baskets from the leaves.

We would cut it green and strip the outer layers off (a bit like taking the outer skin off a spring onion) then let them dry before splitting them by battoning through. All bamboo I have found in the UK has been too dry and feels brittle. Just picking it up tells me it's not up to the job because it's too light. We were told not to split the green bamboo because where the splinters entered and any cuts would get infected. I have no way of knowing if that was a story or true. The splinters were truly frightening - they could be inches long, go from a needle sharp point at one end to a centimetre wide at the other, and go straight through the skin between your thumb and finger, or even slice straight along and under the skin of the palm of your hand - the pain of taking them out was even worse. Actually, thinking about, I may have psychological reasons for not making bamboo bows these days

 

[bobnewboy]

Do you know where the bamboo came from and what it was used for? It isn't something I associate with North Africa.

I have had a 70mm bamboo log, about six feet long, split in half, in a corner of my shed for about 12 years. It was bought from a garden centre with the intention of using as backing with some hickory I bought. Never got around to it. I love wood work, and enjoy bow building, but the splintery nature of bamboo kind of put me off. I have never seen material that size for sale again. I know that Wayne buys his specially from somewhere that imports it themselves. Material scarcity always makes me cautious about jumping in without a detailed plan.

What do folk think about the other question, buying boards unseen and hoping they are bow suitable? I have always been able to pick my boards and have it in mind that this is important. Maybe if the aim is just 30lb and one can back and/or go wider it isn't so much of a risk? Thoughts?

In the case of bamboo bows made in the Bhutanese style, the draw weight is nearly completely determined by the bamboo wall thickness. The bow that I made was 25-30lb @28” after a light heat treatment, and that was around a quarter inch thick wall and an inch and a half at its widest point. If your pieces are thicker and sound you should easily make a 30lb bow.

I agree that bamboo is a little tricky to work with, and you have to be especially careful with the edges as the splinters can be nasty. But it is very tough, particularly in tension, which is why it makes a good backing for laminated bows. In those bows you do need to match it to a very hard/resilient belly wood. But this is getting away from all-bamboo bows

The best bamboo for all-bamboo bows is the thickest and widest (largest diameter) poles you can find.

edit: just noticed the other question. You can buy wood for bows unseen, but since most timber suppliers have no idea what you’re really after, you will generally end up with one useable piece out of a dozen, I.e more by luck than judgement. If you can afford that, or have other jobs for the unsuitable pieces, crack on. Really though, you want to see the timber before buying.....

 

[TLM]

Hmm ... must be getting old, only remembered these after a few days. I have 5 bamboo slats waiting for some kind of inspiration to build some bows. Just now I have little idea what kind.

A friend has a genuine Bhutanese bow he brought back some ten years ago, must visit him and take some pics and measures.

 

[Ch@rlie]

recall seeing this, not sure if he did others.
JungleCrafty on YouTube

 

[Xanderd]

Hi,

I've just spent the last 2 weeks making Bhutanese bamboo bows and am now super frustrated as they have all broken!

I'm using Moso bamboo from a UK supplier. Dry, 1cm thick walls, 150mm diameter, 3 m long, and I split it down to size.

1. Firstly can I confirm that the inside of the bamboo pole faces away from you on the bow, and the hard shiny bamboo outer faces the archer?

They draw really well up to about 20 inches, then I start to hear fibres popping, and at full draw (28inches) the whole thing just snaps in half.

The weird thing is one of them split and cracked and I flipped it round and it seems invincible the other way round! Even with the crack I can easily draw 28-30 inches and just feel it flexing rather than popping. Makes me feel like I've been doing it the wrong way round even though I've followed all the descriptions I've read!!

2. I've tried many measurements, settling on around 160cm total length, 23cm overlap of the 2 staves, a 4.5cm width handle tapered down to 2.5cm tips. Does this sound reasonable?

My first one was much thinner but only had like a 10 lb draw. By making it thicker and shorter I got up to around 30lbs.

I've been so careful on the construction, tightly wrapping it and sanding it. Ive tried overlapping the staves by 21cm and even 30cm.

Even my very thin one (3cm handle, 1.5cm tips) o can hear tearing the fibres when I draw it, but if I flip it the 'wrong way round' it just springs into a complete curve.

I'm exasperated!

 

[Deleted member 56522]

1. Firstly can I confirm that the inside of the bamboo pole faces away from you on the bow, and the hard shiny bamboo outer faces the archer?

Bamboo will have evolved to be strongest when the outside is under the most tension, which suggests to me that that the shiny surface should be away form the archer.

 

[Xanderd]

This is the logic with trees, but many sources say it's the other way round.

I just experimented with flipping it (shiny side out) and although it feels a lot stronger it suffers from a lot of string follow/set and has a lot less shooting power

I hope the bamboo I bought is crap to be honest because then the fault is on that and not me!

 

[Broch]

We had no idea about the theory of building them when I was a kid - as I said in an earlier post - so, whereas what we did may have been completely wrong, it worked!

We always used the outer (shiny surface) as the back of the bow (the bit under tension, away from you).

 

[bobnewboy]

As above I’ve used the bamboo with the inside surface as the back of the bow. I’ve removed most of the cross walls on the inside, but I don’t flatten them completely. I set the limbs forward of the handle section using heat from a heat gun and bending them forward over a former. That adds a little draw weight and arrow speed, but you do need to evenly brown the boo at least.

I also noticed ticking noises when first drawing my bow. That is the last thing you usually want when trying a bow, but in this case it was just the varnish-like natural inner coating of the boo cracking, and had no effect on the bow.

In the end, as with all natural bows, everything depends on the material you have. IME, you need a piece from the widest pole you can find (4” minimum diameter), with the largest node spacing and the thickest walls possible. Then you get onto the condition. Bamboo can get too dry and degrade even in quite good conditions Look at the outside coating of the pole. It should be slightly waxy and not dry or powdery.

If you can find some big poles like that you should be ok.

Cheers, Bob

 

[crosslandkelly]

I still have the Bhutanese bow I made with Wayne at the moot, a good few years ago. It has lost some of it's draw weight but still pulls about 20 odd pounds at 28 inches.

 

[Robson Valley]

The Paleoplanet Forums have several sections devoted to bow making. More than I have ever seen anywhere. I suggest those as a very diverse source.

 

[Xanderd]

thanks, I have had 5 bows snap on me and have reassured myself that the inside of the bamboo should be the back of the bow. So I'm guessing I just didn't have the right piece of bamboo (too old, too dry, ??). Which is a shame as I bought 2x3m poles for £50.

I might try laminating 2 outers together if I get the energy.

@Broch - yes I tried flipping a bow so the outer bamboo was the back and it bent as far as I could pull it without any noisy cracks! The only problem is, the draw weight was a lot less, and also it stayed bent and suffered a lot of set. So I can see why people in Bhutan invert them as that dense shiny outer gives a lot of snapping force when used as the belly.

I'm going to try another species of bamboo (Guardu) and will report back.

 

[TLM]

The outer layer under the "enamel" contains the load bearing fibers of bamboo, weather tension or compression. So laminating it is by far the best way.

 

[Wayne]

I'm have made several hundred bows from Bamboo. The photos above are some of my earliest models. I no longer use gaffer tape. They still use insulation tape in Bhutan. Bows have been manufactured from Bamboo for 1000s years. The Yumi bow for example served the Samurai horse archers pretty well.

Bamboo is easy to work compared to Yew or Elm.

My personal Himalayan Bows range in draw weight from 45 -55lb at 26 inches. This gives an arrow speed of around 170 fps. Comparable to my laminate long bows they are actually slightly faster as bamboo is lighter and more efficient.

Bamboo species I use are Moso or Black Bamboo. Black Bamboo is harder to work but makes a heavy draw weight bow. Heavier draw weight means more chance of snappy snappy.

The inside of the bamboo is the back of the bow. There are two reasons for this.
Firstly if you're making a Bhutanese Bow it will give a natural recurve.
Secondly it ensures you're not damaging the power fibres and is much less likely to set.
Aaron's Bow he made on my first course at the moot is still shooting with a decent draw weight. Must be 10 years old by now.

 

[VaughnT]

Don't forget, your hardware stores will have lots of good bow staves in the form of handles for post-hole diggers, shovels, etc. You might have to join two staves at the handle, but that's relatively easy to do with a sheetmetal socket you can make yourself.