I like Chinese (Bows) - Part II

[GrahameA]

Evening All

Write-up and Pictures to follow.

So here it is - the Mark II. Turned out lighter than I was aiming for but shoots light aluminium's great.

There is a high frame rate video of it being shot on YouTube.
YouTube Video

After the Mark II I went somewhat thinner on the laminations, changed the angle of the siyahs, their design and the method of attachment. Draw Weight 19@28

1.jpg (126.79 KiB) Viewed 6171 times

Next step will be to build another - but heavier - in a few weeks - which will build on the lessons I have learnt.

You would not believe how much I have learnt from doing this one - and that is on top of the lessons from the first one. And once again - Thanks Daryl.

[Gringa Bows]

looks pretty good Grahame,is 19#the weight you were after......Rod

[GrahameA]

Hi Rod

looks pretty good Grahame,is 19#the weight you were after......Rod

No. 40lbs. The change from the desired is a result of me not thinking about things. I a, relaxed the amount of reflex and b, the angle of the Siyahs. Another lessons from the School of Building Asiatic bows. When I get some longer arrows I intend to try it with a thumbring and drawing it to behind the ear.

[Graeme K]

Looks good Grahame --- easy to get the weight right if you rebuild with the same design but as you found, changing a bunch of things makes it difficult.
Glad it worked out for you and looking forward to seeing some more photos and testing.

Graeme

[longbowinfected]

Very sweet bow.
You have given me a bit of an itch/idea.

I would like to show the beginners in my courses a range of bows and let them have a play.
We also do a come and try archery shoot at the Ironfest festival in Lithgow each year. A few of us dress up in ye olde in keeping with the spirit shown by the SCA folk.....I would recommend it to anyone intersted, just Google "Ironfest".

I would love to have any "rejects" that are serviceable/useful between 14-20 # from any/all of the bowyers here including a horse bow or two, flatbows, modern longbows and a couple of ELBs. Of course there is never a shortage of little uns looking for bows. Maybe as a promotional thing the members of the site get together a lending library for special events......be a good way to get the kids in. You could book the loan for a week and pay the freight to the next party...but have to put pix in an album and say get participants and the bowyers to sign in a contact book.

Probably have to make up a pine box to send them, pack them in.

Just an idle thought.

Kevin

[MaylandL]

G'day Grahame

Nice looking bow! I noticed that there was some limb and string vibration after the bow was shot. How does the bow feel when being shot? I know with my Grozer mongolian, that it feels like my hand is being kicked when the string hits the string stops.

Also I noticed that with my Grozer bows, the siyahs are also bound with treated hemp when attached to the limbs and the limbs are also bound with the esame material at the points where the limbs joins the riser/hand of the bow. Interesting to see that you have opted not to use any binding.

Looking forward to seeing how the next one develops.

Happy shooting

[Mick Smith]

It looks great Grahame! I like the way you've built and attached the siyahs.

The black glass almost looks like horn too.

Mick

[jcm]

Ah Master.
The bow looks good.
Will the sister be better?
Only the New Year and lessons learnt will show.
Look forward to it.
All the Best
John

[greybeard]

I like Chinese has been a very interesting and rewarding project.

Over the years I have been playing around with static tipped bows constructed from natural materials or a combination of natural and synthetic.

The project that Grahame suggested was a worthy challenge.

Mark 1 highlighted the fact that traditional designs using natural materials cannot necessarily be replicated without modification when using synthetic materials.

As mentioned in some of my previous postings on static tipped bows the working limb length and side profile was of prime consideration when making one of these bows.

It was not until this latest project that I realised the importance that siyahs [levers] played in the overall performance of the bow.

Although the bow may be 19# at 28”, when unbraced and pulling the limbs back at the base of the siyahs it feels more like a 35# bow. Undoubtedly there is a mathematical formula to work out the limb/siyah ratio as well as siyah angle to the limb.

Hi MaylandL,

I believe that the excessive string vibration was caused by overweight siyahs in relation to the draw weight of the bow.

With the method of trapping the siyah in the core of the bow binding would appear to be unnecessary unless getting into heavy poundages.

When you look at illustrations of bows made from sinew, horn and a bamboo/wood core, bindings were not evident. The bows usually had sinew encasing the siyah/limb joint.

Possibly the use of bindings on the current run of synthetic bows [I won’t include the Grozer as I have not seen one in the flesh], is to hide the attachment method and dress up the bow. Binding on the fadeouts of the handle should not be necessary.

Daryl.

[GrahameA]

Morning All

Welcome to 2009. It is warm night tonight.

Hi Graeme

Looks good Grahame --- easy to get the weight right if you rebuild with the same design but as you found, changing a bunch of things makes it difficult.
Glad it worked out for you and looking forward to seeing some more photos and testing.

Graeme

I really need to sit down and cogitate over this for a while. I have some notes on spring design somewhere and it would probably be worthwhile to get them out and read them a few times.

Hi Kevin

I would like to show the beginners in my courses a range of bows and let them have a play.

I generally take along a bundle of my bows on the last day of our beginner courses for people to try out.

Hi Wing

G'day Grahame

Nice looking bow! I noticed that there was some limb and string vibration after the bow was shot. How does the bow feel when being shot? I know with my Grozer mongolian, that it feels like my hand is being kicked when the string hits the string stops.

Also I noticed that with my Grozer bows, the siyahs are also bound with treated hemp when attached to the limbs and the limbs are also bound with the esame material at the points where the limbs joins the riser/hand of the bow. Interesting to see that you have opted not to use any binding.

Looking forward to seeing how the next one develops.

Daryl has answered most of the questions and I concur with his statements.

The issue of Siyah mass is interesting. The objective is to get them as light as possible and yet not break under the imposed loads. There may be advantages in using natural crooks for this. Having said that the next one may well have laminated ones for a couple of reasons. Strength, ease of construction and shaping.

Note with the video that it is shot at 300 frames per second. That is around 12 times faster than what you normally get. It definitely vibrates a bit after the shot but how better or worse that is in comparison to similar bows at this point in time I don't know. Need to film some more bows. Having said that it is fine to shoot with no noticeable shock at all.

I do have on my list of projects for 2009 to film a range of bows at high frame rates so that I can get some ideas of how they perform/react when shot.

On the topic of Siyah attachment this time around there is a much larger glue area. I will probably put some small bindings on it - belt and braces, Since the Mark I I have done a bit of investigation into how other people have attached them. When I return to the Mark I I intend to wrap some glass cloth around the section where the Siyah fades into the limb.

Hi Mick

It looks great Grahame! I like the way you've built and attached the siyahs.

The black glass almost looks like horn too.

Mick

Whilst I would like to take credit for the Siyah attachment that is Daryl's design and my implementation. Yes, the black glass does look like Horn strips and interestingly I have read of bows where short sections of glass has been used to replace the horn.

Hi John

Ah Master.
The bow looks good.
Will the sister be better?
Only the New Year and lessons learnt will show.
Look forward to it.
All the Best
John

Still very much an apprentice at this stuff. The sisters will be better. It is my opinion that the only way to learn is to have a go. It can be very difficult to learn Brain Surgery at the feet of a Guru - eventually you need to get your hands dirty.

Evening Daryl

When you look at illustrations of bows made from sinew, horn and a bamboo/wood core, bindings were not evident. The bows usually had sinew encasing the siyah/limb joint.

Possibly the use of bindings on the current run of synthetic bows [I won’t include the Grozer as I have not seen one in the flesh], is to hide the attachment method and dress up the bow. Binding on the fadeouts of the handle should not be necessary.

is to hide the attachment method and dress up the bow I would concur with that. In addition, the method used for the attachment may require the binding to stop 'peel' occurring.

For me this has been but a short walk down the beginning of what is starting to look like a very long road. I already have been thinking about the next one which will probably be a modern Homellgarde (spelling). The reason for that is that I should be able to extract some data from it which can be used to assist in the design of Siyahs. There really is a huge amount to learn.

[Stickbow Hunter]

Good to see you enjoying your new projects mate and I hope the next one will be even better.

Jeff

[DylanK]

It was not until this latest project that I realised the importance that siyahs [levers] played in the overall performance of the bow.

Although the bow may be 19# at 28”, when unbraced and pulling the limbs back at the base of the siyahs it feels more like a 35# bow. Undoubtedly there is a mathematical formula to work out the limb/siyah ratio as well as siyah angle to the limb.
.

Would this mean that you would be able to pull higher poundages with bows that have siyahs than without? Or are you saying that the siyahs lower the poundage of the bow?

Dylan

[MaylandL]

...It was not until this latest project that I realised the importance that siyahs [levers] played in the overall performance of the bow.
...
I believe that the excessive string vibration was caused by overweight siyahs in relation to the draw weight of the bow.

With the method of trapping the siyah in the core of the bow binding would appear to be unnecessary unless getting into heavy poundages.

G'day Daryl/Grahame

I was wondering if you have had the opportunity to reasearch ATARN ( http://atarn.net/phpBB2/index.php ).

It does have some interesting discussion on construction of bows.

As for the siyahs on my grozer bows, the size of them on the hunnish and mongolian are thinner and longer than your bow. The siyahs on my horn avarian are are thicker and larger. The siyahs do make a significant contribution to the performance of the bow. Of the horsebows that I have the hunnish is by far the best performing bow, part of which may be the asymmetric design - the top siyah is longer by about 30%. Even though the horn avarian is a slightly heaver bow than the hunnish (57# vs 55#), the hunnish is the better peforming bow.

Looking forward to the results of the next version. Happy shooting

[greybeard]

Hi Dylan,

It does not mean that you can pull a higher poundage bow, 50# is 50# no matter which way you look at it.

With static tipped bows you have relatively shorter working limbs in relationship to the overall length of the bow. Because of this and the leverage advantage gained by the siyahs you need to overbuild the working limb area to compensate.

Imagine if you had a 68” longbow, 50# @ 28” which you can comfortably shoot. Cut 10 inches of each limb, file in some string nocks and try drawing it to 28”. No doubt a difficult task, but add 10” siyahs and you might get it back to 28”.

I do apologise if my reply is a little vague, perhaps another member can explain in more precise terms.

Hi Wing,

I do need to spend more researching ATARN.

I believe that the mass weight, not size of the siyahs on Mark11 was a larger part of the problem. The under built limbs cannot successfully move the tip weight.

With the two bows that you mentioned how similar are they in profile when unbraced and braced? Are the core construction/materials identical in both bows?

Do you know what timbers were used in the siyahs of your bows?

Making static tip bows is a whole new ball game.



Cheers,

Daryl.

[GrahameA]

Evening All

Only the first day of the new year.

Making static tip bows is a whole new ball game.

And this may yet be the "Understatement of the Year".

For those who are interested another method of fitting the Siyahs

Siyah Link

[DylanK]

Thanks Daryl, I understand what your saying

[MaylandL]

G'day Daryl

...With the two bows that you mentioned how similar are they in profile when unbraced and braced? Are the core construction/materials identical in both bows?

I've attached pics from the Grozer website of the mongolian and the hunnish braced and unbraced. Hope this helps.

Braced Hunnish bow (sourced Grozer Website)

HunnishBraced.gif (10.79 KiB) Viewed 5753 times

Braced Mongolian bow (sourced Grozer Website)

MongolianBraced.gif (4.58 KiB) Viewed 5753 times

Unbraced Hunnish bow (sourced Grozer Website)

HunnishUnbraced.gif (8.11 KiB) Viewed 5753 times

Unbraced Mongolian bow (sourced Grozer Website)

MongolianUnbraced.gif (4.59 KiB) Viewed 5752 times

The core construction on the mongolian as I understand it is wood with fibreglass reinforcing. I understand that the hunnish is similar construction but there has been improvements in the construction method. Understandably, Grozer is not willing to share any further details as they are his design patents and intellectual property.

Another interesting point, Grozer now has a forum on his website ( http://www.grozerarchery.com ).

Do you know what timbers were used in the siyahs of your bows?

I understand that the timbers used in siyahs for both the mongolian and the hunnish bows are ash and cherrywood


Happy shooting in the new year

[pommy chris]

another good try mate.and this one you can shoot.this is a good learning curve your on now.i hope you keep at it and keep posting your experiments. im sure you will get the results you are after.any pics of the bow unstrung?

[GrahameA]

Hi Chris

another good try mate.and this one you can shoot.this is a good learning curve your on now.i hope you keep at it and keep posting your experiments. im sure you will get the results you are after.any pics of the bow unstrung?

I will see Daryl on Monday and collect all the photos he has of the bow being made and then in conjuction with the photos I have of the Mark I, I will put together a post showing how the bows where built, etc.

Morning Wing

The core construction on the mongolian as I understand it is wood with fibreglass reinforcing. I understand that the hunnish is similar construction but there has been improvements in the construction method. Understandably, Grozer is not willing to share any further details as they are his design patents and intellectual property.

Now that is interesting as I could use that exact description for the construction of the bows. They are timber reinforced with fibreglass. And if I was Grozer and making them for a living I would be a little cagey about how I was doing it as well. Both Daryl and I have learnt a lot in making these and it is a very steep learning curve. Plus to get them to a shooting stage takes a few hours - a lot more than most would expect. They are a complex piece of kit and seem to demand a much higher level of skill in fitting and hand tools use when compared with a typical longbow. I am becoming very good at using my new tool of choice - the Sanding Block. Sand - Test fit - Sand - Test fit - Sand - Test fit - Sand - Test fit.... my new mantra.

I understand that the timbers used in siyahs for both the mongolian and the hunnish bows are ash and cherrywood

Now that is a bit good news. The Siyahs on the Mark I are either Cherry( or Ash). It may be a little soft and may require reinforcing with a harder material if it is to withstand long use.

An Addenda.

I have just been thinking about Static tip bows and developing some mathematical models. I will assume that those interested in such will have read Hickman's work of bow modelling. This is another similiar but is directed towards Static Tip bows. "The Statics of the Traditional Hungarian Composite Reflex Bow"

[greybeard]

Hi Wing,

Thank you for the photos and siyah details.

The bows appear to be significantly different in profile. Also the Hun appears to be thinner in the limbs.

From shooting the bows do they have similar draw characteristics i.e. rate of increase of draw weight through the draw cycle?

Cherry or similar density woods appear to be the better choice for reducing siyah mass.

The working areas of the limbs [depending on siyah length] may have to be up to double the desired draw weight.

The diagram may help clarify my reasoning. The stated poundages are meant to be illustrative and not factual as I do not have the testing facilities.

Diagram Of Static Tip Bow.jpg (53.69 KiB) Viewed 5624 times

Daryl.

[jape]

I find the balance between Pythagoran/Archimedian numbers magick and the intuitive and still empirical sand/test/sand/test process rather interesting. Real creative craft here.

[greybeard]

Hi Grahame,

Interesting reading but there are a lot of serious calculations in ‘The Statics of the Traditional Hungarian Composite Reflex Bow’

I doubt that I could ever understand all the maths so I will have to progress by experiment at present, which is probably the way the Huns progressed to their final designs.

Daryl.

[GrahameA]

Hi Daryl,

I doubt that I could ever understand all the maths

Neither will most people. Don't worry about the maths it is the concepts that are important.

Ahh... love the cool weather.

[Nephew]

I like Chinese

Even if they only come up to your knees? Ah well, I 'spose, their fun, and their witty, and their ready to please!
(Someone had to do it! I've been waiting since Mark1 a couple of weeks ago for someone to say this! )

[MaylandL]

...
From shooting the bows do they have similar draw characteristics i.e. rate of increase of draw weight through the draw cycle?
...

G'day Daryl

Both bows are very smooth to draw with little stack at 28". It's constant through out. Not surprising when the max draw length is about 30". Even so the horn avarian does not exhibit any stack at 28" even though its max draw length is 28" and is equally constant and smooth to draw.

As for your hypotheses in your diagram, it would be worth while putting that to the test in other bows and getting comments on ATARN.

Good luck with the experimentation.

Happy shooting

[GrahameA]

Morning Wing

As for your hypotheses in your diagram, it would be worth while putting that to the test in other bows and getting comments on ATARN.

It depends a little on what you are chasing but eventually you end up with a full working recurve as you make the Siyahs smaller and smaller. The optimum is probably a working recurve and thus you end up with a "modern" bow.

Having said that, it is interesting to consider what happens as you vary the amount of reflex and recurve in the limbs and the Siyah angle. (You also end with a Coffee Table full of little sketches.). In some respects you are bound by the properties of the material you are using which may be the determinant factor WRT working limb length.