Ozbow

Sy, Further to rule 2 in my post above about the cubed relationship of thickness to draw weight. The following picture is an approximate illustration of how it works. There is a set of mathematical equations about it and the relationship is not as linear as this diagram supposes, but it is a useful ...

That's fine, Sy. I understand that. There are plenty of very talented people here on Ozbow who will be very happy to help you. Some of the advice will conflict at times and that will make it a bit hard for you as a beginner to make progress, so you will have to use some judgement with advice given. ...

Sy, It isn't as simple just halving the thickness as Daryl can vouch. There are a few basic rules of bowmaking I should point out. They are not hard and fast, but they are a very good guide. For any bow of given dimensions - 1. A bow which is made twice as wide where every other dimension is equal t...

This is why you can't generally use the dimensions of northern hemisphere timbered bows when using Australian hardwoods. Sy, Daryl is right there. Using the dimensions from the original artifact using Spotted Gum will produce a bow which would be Herculean in draw weight. As the specs which Daryl s...

Dean, From my previous medical background as a Registered Nurse, my advice is to first concentrate on making sure that your shoulder is COMPLETELY healed before you even think of taking up shooting again. If it hurts, damage is still present and healing is not completed. Just stick to your physio un...

Sy, Here is a schematic of the original artifact. You can't go too wrong if you follow it. Note that the characteristic Holmegaard/Møllegabet shoulder is not well defined if at all, and some archaeologically minded archers contend that they were never a characteristic of the originals of the time. H...

Perry, Very well done. Good on you. That would have been very fine shooting indeed. And yes, I have always canted my bow. I don't cant it for any particular range. The cant is completely natural and is the position my bow arm assumes when I hold a bow out at arm's length with a relaxed wrist. Holdin...

Colin, Daryl is right. That little bow could easily stand another 4 inches of draw from that bow, OR you could shorten it 2 inches at each end without a problem. You look to be drawing only 27 inches in that picture. On the bendy handle ELB styled bow, I work at a minimum length of 2.5x draw length,...

Mick, I am grateful to you for providing the reference sources that you did. I was never intellectually locked against it, but I was locked against unsubstantiable and unsubstantiated claims. I can understand now why you prefer the process, however as I began with, I have never had a problem with ar...

Neil, That all makes perfect sense to me and pretty much iterates everything I have been able to understand from Hickman, Klopsteg and Nagler. Your explanation is a lot shorter as well. There is some pretty complicated maths in the publications of the 3 archery greats (they are to me anyway, even mo...

Mick, I have gone through Mick's list of references and I now consider that the technique is a valid tool in archery, but that its best and most appropriate use is as a remedy for problems with arrow flight which have been demonstrated and persist after all the usual rules of selection of arrow sha...

Mick et al,

I have gone through all your references and now I think I have a pretty good idea of what you blokes are on about. I will post some more about it a bit later.

Mick, Many thanks for all the references and the trouble you have gone to. I appreciate that and I will go through them all as diligently as possible and let all of you know my views afterward. Please do not misunderstand my intentions with my posts above. If I thought for one second that there was ...

BowmanBjorn, We have a species called Red Ironbark (Eucalyptus sideroxylon) down our way in Southern NSW and Victoria. I have used a good bit of it and it works fine. Yeoman on this site has made many more bows from it than I have but usually backed with Bamboo and he recommends it. It has an ADD of...

Perry and Mick, I too do a lot of experimenting with my equipment as you all well know by now, but I have never seen the need to bare tune my shafts BEFORE I have established that I actually had a problem with arrow flight. The way in which proponents advocate using the practice appears to me as tho...

My answer to the quiz above is that I NEVER bare tune my shafts - never have and have never had any kind of problem. Selecting my arrow shafts base purely on having a fairly reasonable amount of stiffness and matching them to each other, has always resulted in accuracy more than sufficient for anyth...

Rod, Get your eyes checked again at the optometrist. It is unusual for eyesight to change so dramatically in such a short time. I cannot offer any kind of prospective diagnosis because my Nursing training barely touched on Ophthalmology. But there are other systemic medical issues which can affect v...

The biggest problem I found with red ash is that it is prone to small drying cracks appearing on the edge of the back years after the bow was made. Daryl, I have made only a few from Red Ash, but I haven't noticed that phenomenon. The wood books call that radial checking because of surface shrinkag...

Neil, I am embarrassed by your kindness. My formal skill level at mathematics is first year secondary school. Anything else is gleaned by dint of pure persistence and trying to understand. Thank you. :oops: I am glad I am on the right track. Daryl, Now I get what you are saying. I have never thought...

It is not of equal distance from either the belly or back except in bows which are symmetrical in cross section. I should also add that the degree of load taken by the back and belly of a bow DOES relate directly to the distance from the neutral axis to the back and belly surfaces. On an ELB of con...

Daryl, You are on the right track there. As Nezwin suggests, the principle has to do with the reason why the concept of trapezoiding the limb cross section to make the back surface narrower. That follows from principles worked out by Hickman et al, back in the 1930s where it was found that generally...

Colin, That picture shows a bow with a circle overlain which would have a focus much further from its circumference than on my example where I treat the bow's curvature as having a value of 2 radians in length. And yes, the outer limbs are way too stiff as you say. It is very apparent and quite visi...

The modern use of the term 'compass' in reference to the shape of well-tillered ELBs is taken directly from the use of the same word by Roger Ascham in his 1545 book 'Toxophilus'. He uses the word quite often in describing the shape of the drawn bow AND the shape of the trajectory of the arrow. Read...

I have also noticed that the originals seem to be very wide AND thick for most of their length and the ends taper very quickly and that is what gives the whip endedness. As you say, you can get the tips moving first with a heavy taper to get them bending first, then address the inboard part of each ...

That gadget on Primitiveways is very clever indeed. I will have a go at it as well.

With regard to me mentioning barrel tapering above, that was a reference to width tapering, not thickness tapering.

Colin,

Those have turned out rather well haven't they? I reckon they will be pretty schmicko with a bit of a polish.

Dan76, With that draw length and the length of the bow, it would be a bit too risky to shorten it to increase the weight. If the bow has come in a little under what I wanted my suggestion is to leave well enough alone. Your bow has barely 23 or 24 inches of working limb at each end, and unless the d...

Colin, Len Buckland was using American Ash for his early EWBs earlier on and I believe that he was having a few failures due to the wood not being up to the load, particularly when it got to the magic 3 figures. Although it could just as easily have been due to the quality of the wood being imported...

Colin, I think the Acetal rod will do a very good job as a stand-in for horn. It won't have the colour variation of horn of course, but that doesn't matter much. It may even be tougher than horn against breakage. Those arrow weights are only in the range of 8.3 grains per LB of draw weight for a 100...

With the 'push-pull' bracing method I use, I found that it is hugely easier when you push your left knee into the lower limb as you pull the upper limb toward you with your right hand a bit above the handle area. I actually do not push the upper loop into the nock. My left arm is just held rigidly s...