Ozbow

It was by coincidence that an earlier posting by Grahame A had resurfaced a couple of weeks ago regarding this style of bow. I was becoming bored with producing fibre glass back and bellied bows and wanted to get back to using bamboo. The style of bow described by Grahame A was in fact going to be my next project. If you don't have a go you will never know!

I had a small illustration of a strung bow in this style recreated by Hillary Greenland as a basis for this project. As you would appreciate it is not always an easy task to take a five inch illustration to a seventy inch drawing and then interpret how the bow would look when unstrung. Having had some previous experience with making bamboo laminated slightly recurved bows I was in with half a chance. Although the bow may come off the form true the form profile, during tillering the recurved tips will pull out / take a set. With a bit of experience you learn how much extra recurve to put into the form to compensate. It is a bit of a grey area but I think the recurve tips take a set and then hold whilst the overall limb takes set and or some string follow.

I decided to attach some photos of the finished bow and not do a build along as the construction techniques are similar to my previous postings on bamboo laminated bows and the only thing that changes is the bow form.

With the excess glue sanded off and the limb widths and thickness trued up it was time to go to the tiller board. The bow was virtually in tiller although there were some stiff spots, almost mirror image one limb to the other. I had expected this as I was down to the dregs of my bamboo stock (some unfriendly nodes). It is for this reason I always use 'twins' when making bamboo bows.

The moment of truth had arrived, being satisfied with the initial tiller it was now time to put on the correct length string to get a true appreciation of the bows tiller. Tillering strings give you a guide to tiller, but not necessarily the correct answer, more so with bamboo bows as opposed to glass bows. You will notice a slight difference (photo 02) in the curve just out from the handle right to left. The tiller held true until after about twenty arrows. What was to be the lower limb may now become the upper limb, as I have found from experience it can take over a hundred arrows or more for the limbs to settle in. This is one advantage with having equal length limb bows as you can up end them if needed if you haven't cut in a shelf or finalised the handle shape. At present the handle shape dictates that arrows are shot off the knuckle. Once the tiller has settled I will do the final shaping of the grip area.

I am extremely happy with the end result as the weight comes in at about three inches into the draw and progressively builds up through the draw and that the string lays true to the centre of the handle. Achieving the graceful flowing lines of this classic style of bow was easier than I had first anticipated. Obtaining the correct profile in the back set handle and limb thickness would determine the degree of curve in the limb from handle to mid limb which would then flow into the gently recurved tips.

The handle section was laminated from a piece of 3x2 hardwood off-cut lying around the workshop floor with a strip of rock maple for a highlight. Tip overlays were of a similar construction. The core is made up of five laminations of spotted gum to a total thickness of 7 mm and Moso bamboo was used for the back and belly.

After some shooting in on the weekend the upper limb took a set that threw the bow out of tiller. Because of the nature of these bows I will shoot a lot more arrows before I start altering the tiller. The arrows (560 grain, footed) go where you point them and there is no hand shock although the bow is out of tiller. Once shooting in the bow I anticipate that it will settle in around the 50# mark.

Unstrung bow is 66" n to n in a straight line and takes a 64" string. The fast flite Flemish string for this bow was made by Steve Wallace.

(Will be off the net for 7 to10 days, stuff up by major Telco)

Daryl.

Hi Darrlyl

Now that is a great looking bow.

Yep, it's nice alright. It sorta looks a bit like an overgrown horsebow without the siyahs. I like it a lot.

Mick

Hi Daryl
Great looking bow. I really like the drawn profile where it is still holding a little recurve.

Grame

Good lookin bow!

Jeff

thats a nice bow .
good job greybeard.

Daryl,

Delighted to see another of your bows using bamboo - you are certainly becoming really proficient at getting the bamboo to work around those tight reflex curves. Was the form used the same one as your horsebows with adjustable blocks ? This IS a lovely little bow and your #2 photo looks like you achieved a perfect match for Hillary's reconstruction. Well done.

Hi Darryl, You have excelled with this one, Does the belly bamboo follow the handle entirely?
I had the pleasure of shooting one of your glass D/R spotted gum bows on the weekend and it held its own against the American glamours that Robert Mckenzie and Les Simpson carry around in their back pockets, No doubt this one is a nice performer. Steve

Good work there Daryl, looks great!

Dave

Yeah. fantastic work way beyond anything I could even contemplate.

Yeah not bad for an amiture

looks great well done.

Thank you for the words of encouragement.

I apologize for not posting a reply earlier but changing to broadband created problems that I did not anticipate.
To answer some of the questions;

Archangel,
I specially made a form for this particular bow. If I decide to make some glass versions of this bow I will have to make a new form (less recurve as the tips will not pullout.) Discarded multi-laminated scaffolding planks make brilliant forms (especially when they are free) but you may have to clean them up a bit. The ones that I got hold of were destined for the fire heap.

GraemeK,
By trial and error you learn how much recurve to put into the tips so that they don't flatten out at full draw.

Steve,
The bamboo back and belly was butt joined at the handle but when doing the shaping of the handle they may fade out into the handle stock.

The next big challenge is to replicate this bow as a selfbow and possibly as a two piece takedown.

Cheers,

Daryl.

Darryl

You have shown how well bamboo can be used to laminate/back a bow effectively. One of the challenges with using raw bamboo for the back and belly - its hard to predict the draw weight and frequently makes the bow so over-powered that it is impossible to draw. Once this happens, the only way to reduce the draw weight is to strip off the belly bamboo which ends up in a virtual rebuild. Your latest bow demonstrates that fine recurves can be achieved with bamboo and encourages me to try again down the track.

Hi Archangel,
I have found that if you work the bamboo to tight tolerences and make them as thin as possible by removing as much soft innner as possible you end up with all power fibres. I use a set of verniers and take thickness measurements at 4" intervals. By doing this you can obtain uniform tapers to the tips. Take care to control the thickness either side of the nodes. Once this has been achieved the bamboo is almost as predictable as glass.
The bow draw weight is then controlled by the core thickness.

Daryl.

Daryl

If you have time, would you mind posting the dimensions by sectors ie. width, thickness etc every 4-6" to give a reasonable guide on how wide/thick you made the core laminations, fades and bamboo backing?

Archangel,

Unfortunately I cannot be too specific regarding lamination thickness as I have been using between two and five laminations. Depending on the type of timber used the overall core thickness can vary from 4 to 7 mm. This thickness and number of laminations is also governed by the amount of working limb, limb length and style of bow and anticipated draw weight.

The following dimensions relate specifically to the 'Italian' style of bow. From end of fadeout to the string nock measuring along the back of the bow is 64cm. I will list the limb widths starting at the fadeout at 6 inch intervals to the tip followed by the corresponding thicknesses. 31.4mm, 28.54mm, 25.2mm, 21mm, 15.44mm. Thickness 13.8mm, 12.3mm, 11.2mm, 10.1mm, 9.5mm. The five lamination core has a thickness of 6.65mm. From the last set of figures you can work out the taper on the bamboo based on the premise that equal thicknesses were used for the back and belly.

Because of recurring wrist problems I can only draw the bow to an uncomfortable 26" and it weighed in at 45#. Hopefully, I will have some chronograph figures in the next few days, and that the above information is useful.

Cheers,

Daryl.

tis a beautifull bow indeed.... i like i would like to be able to build bows like that, but its just practice eh? and pull a bow that heavy too....

Something went wrong with posting

Hi coolhippy80
As a kid I would try to make a bow out of any kind of branch or offcut of wood I could find. I 'borrowed' dowelling that my dad had to use for arrows and the fletches were cut out of thin cardboard and stuck to the dowell with stickytape. My re introduction to bow making happened at an early Longbow Muster at Tiaro. Perry Jackson was running a selfbow making demonstration and I ended up buying a roughly cut board blank. After making numerous selfbows as well as suffering several disappointments I did not lose the desire to make bows. From this point I progressed to multiple laminated bows. I still firmly believe that perfecting the art of selfbows forms a firm foundation to expand your bowyer expertise. The selling of selfbows actually funded the purchasing of the equipment needed to produce multi laminated bows. The downside is that a bowyers apprenticeship never ends and you will still be learning while they screw down the lid on your pine box.
Regarding draw weights, as my age goes up the draw weights come down.
The real challenge now is to build a lighter poundage bow that has good performance to shoot around the ranges.

Daryl.

i did the same thing when i was much younger, im 15 now, but my arms are sticks, but my comfortable draw weight is growing

Hi Archangel,
I need to correct an oversight in an earlier reply regarding the glue up. Although I made a solid form for this bow only the core and belly were glued up on it. A moveable form was used to glue the backing bamboo.
I hope my oversight was not too misleading.
Cheers,
Daryl.

Very interested in this bow design. Might be time for a new form

A really nice bow, Daryl, great skill involved there.

Ay Folks, I now have this Bow, Dary was not entirely happy with its performance, so he shortened it by 4 inches and made it into a Take down 2 piece. I really enjoy shooting it , it's a dream to hold and it has no shelf which is what I like, shooting of the hand It's also a dream to shoot and at 38lbs it can be used all day with no fatigue
Thanks Daryl for a Great Bow. Just Love It. Cheers Roadie. .

G'day Roadie, thanks for the update.

Love the style of this bow, you wouldn't have a current photo you could post.
Thinking about making a laminated glass/bamboo version of this bow with static tips (reverse wedges).
Been scribbling a few calculations and ideas down. Already have the plywood wood glued and screwed ready for the design.

Cheers Muz

Hi Muz,

With the bow being made from natural materials some of the initial amount of recurve pulled out.

Cutting 4'' out of the handle did improve the bow but may have contributed to some string follow.

Daryl.

Thanks Daryl and Roadie,

got me interested that's for sure. Hopefully you might see my take on something similar shortly.

Cheers Muz

Hi Muz,

Hope all goes well with the project.

The bows ‘soft’ profile makes it an excellent bow to shoot all day, the only apparent trade off being the loss of a few fps in arrow performance.

Daryl.