G'day
I have a few questions about bowmaking.
1- Should the center of the bow be the middle of the handle or where the arrow rest is? does it matter?
2- Is there any benefit from backing a bow with the same wood eg. a spotted gum backed spotted gum bow or is it better just to use something else.
3- In greybeards topic "building a three piece take down bow" he mentions that the core is 4 laminations of spotted gum, what is the purpose of this, is it stronger than just using a solid core.
4- Ironbark vs Spotted gum in your opinion which one is better for making bows and why?
Thanks
Daniel
A few bowmaking questions
Moderator: Moderators
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Running Bear Eagle Eye
- Posts: 78
- Joined: Fri Jul 28, 2006 4:56 pm
- Location: Melbourne
Hi Daniel,
Although a 50 / 50 question there are probably several schools of thought. Probably a simplistic answer is that you will balance the bow in the final tillering. I would suggest that people such as Dennis LaVarenne or Jeff Challacombe could give you a more definitive answer.
If you want to back the bow with a similar timber I would suggest that you use the late growth of a bush billet as a milled board would have had its growth rings violated.
Bamboo is a good alternative.
I use multiple laminations as I glue them up on a form to build in five to six inches of reflex. To achieve similar on a single core would take a lot of steaming and in the end result you loose 50% or more of the reflex. Multiple laminations can also give you more durability as you are reducing potential weak spots.
As timber qualities can vary within a single species it is best to try various ones and see which one works for you.
Daryl.
Although a 50 / 50 question there are probably several schools of thought. Probably a simplistic answer is that you will balance the bow in the final tillering. I would suggest that people such as Dennis LaVarenne or Jeff Challacombe could give you a more definitive answer.
If you want to back the bow with a similar timber I would suggest that you use the late growth of a bush billet as a milled board would have had its growth rings violated.
Bamboo is a good alternative.
I use multiple laminations as I glue them up on a form to build in five to six inches of reflex. To achieve similar on a single core would take a lot of steaming and in the end result you loose 50% or more of the reflex. Multiple laminations can also give you more durability as you are reducing potential weak spots.
As timber qualities can vary within a single species it is best to try various ones and see which one works for you.
Daryl.
"And you must not stick for a groat or twelvepence more than another man would give, if it be a good bow.
For a good bow twice paid for, is better than an ill bow once broken. [Ascham]
“If a cluttered desk is a sign of a cluttered mind, of what, then, is an empty desk a sign?” [Einstein]
I am old enough to make my own decisions....Just not young enough to remember what I decided!....
For a good bow twice paid for, is better than an ill bow once broken. [Ascham]
“If a cluttered desk is a sign of a cluttered mind, of what, then, is an empty desk a sign?” [Einstein]
I am old enough to make my own decisions....Just not young enough to remember what I decided!....
-
Dennis La Varenne
- Posts: 1776
- Joined: Sun Sep 07, 2003 10:56 pm
- Location: Tocumwal, NSW. Australia
Daniel,
Daryl is correct about the relative strength of laminated vs self limbed bows. Laminates, especially when glued with a reflex will always hold its reflex much better than a self limbed bow which has reflex put into it by heat bending (steam or dry).
In backing a bow, it depends on why it needs backing in the first place. If it is to hold a reflex, it is the same as a 2-lam limb. If the limb has serious problems of grain running out of the limb over too short a distance, or other problems like knots if you have a board, then definitely back it.
With the exception of bamboo, the usual method is to use a wood backing which has the same density as the belly wood to ensure a reasonable degree of similarity in the mechanical properties of the woods used. The backing layer, of course, must be fault free.
So far as the middle of the bow is concerned, I recommend that you tiller your bow so that the line of the arrow is the dynamic centre of your bow. The easiest and simplest way is to make the upper limb at least one inch longer than the lower by having your the middle of your handle one inch or more below the middle of the overall length of the stave.
Once you do this, you will find that the angle of the string on the drawn bow will be very nearly equal above and below the arrow. This will equalise the thrust from both limbs on the arrow and keep any handshock to a minimum.
So long as the limbs bend evenly over their length to distribute the bending load evenly along each limb to prevent eventual fretting, try to tiller so that the string angles are equal throughout the draw and never drawing the bow past its intended draw weight at any stage of tillering.
A bow with same length limbs can be tillered to keep an equal string angle with much more difficulty. The upper limb will have a tighter curve than the lower at full draw. This is called positive tiller.
I am presently doing a lot of experimenting on this layout because of debates on this site in regard to opposing views about whether positive or negative tiller is the correct tillering method.
Dennis La Varenne
Daryl is correct about the relative strength of laminated vs self limbed bows. Laminates, especially when glued with a reflex will always hold its reflex much better than a self limbed bow which has reflex put into it by heat bending (steam or dry).
In backing a bow, it depends on why it needs backing in the first place. If it is to hold a reflex, it is the same as a 2-lam limb. If the limb has serious problems of grain running out of the limb over too short a distance, or other problems like knots if you have a board, then definitely back it.
With the exception of bamboo, the usual method is to use a wood backing which has the same density as the belly wood to ensure a reasonable degree of similarity in the mechanical properties of the woods used. The backing layer, of course, must be fault free.
So far as the middle of the bow is concerned, I recommend that you tiller your bow so that the line of the arrow is the dynamic centre of your bow. The easiest and simplest way is to make the upper limb at least one inch longer than the lower by having your the middle of your handle one inch or more below the middle of the overall length of the stave.
Once you do this, you will find that the angle of the string on the drawn bow will be very nearly equal above and below the arrow. This will equalise the thrust from both limbs on the arrow and keep any handshock to a minimum.
So long as the limbs bend evenly over their length to distribute the bending load evenly along each limb to prevent eventual fretting, try to tiller so that the string angles are equal throughout the draw and never drawing the bow past its intended draw weight at any stage of tillering.
A bow with same length limbs can be tillered to keep an equal string angle with much more difficulty. The upper limb will have a tighter curve than the lower at full draw. This is called positive tiller.
I am presently doing a lot of experimenting on this layout because of debates on this site in regard to opposing views about whether positive or negative tiller is the correct tillering method.
Dennis La Varenne
Dennis La Varénne
Have the courage to argue your beliefs with conviction, but the humility to accept that you may be wrong.
QVIS CVSTODIET IPSOS CVSTODES (Who polices the police?) - DECIMVS IVNIVS IVVENALIS (Juvenal) - Satire VI, lines 347–8
What is the difference between free enterprise capitalism and organised crime?
HOMO LVPVS HOMINIS - Man is his own predator.
Have the courage to argue your beliefs with conviction, but the humility to accept that you may be wrong.
QVIS CVSTODIET IPSOS CVSTODES (Who polices the police?) - DECIMVS IVNIVS IVVENALIS (Juvenal) - Satire VI, lines 347–8
What is the difference between free enterprise capitalism and organised crime?
HOMO LVPVS HOMINIS - Man is his own predator.
Hi all.
Dennis this is for you in particular.
I have a fiberglass semi-recurve hunk-a-junk that I picked up from a mate for $15. I made another handle for it and I put the shelf in the exact centre of the bow (between tips). The handshock on this baby is incredible and after reading your post I was wondering if it would be worth moving the handle down the bow to decrease this shock.
Good questions too Daniel. I'm sure it's not only you and I who are learning from this thread.
Regards.
Oliver.
Dennis this is for you in particular.
I have a fiberglass semi-recurve hunk-a-junk that I picked up from a mate for $15. I made another handle for it and I put the shelf in the exact centre of the bow (between tips). The handshock on this baby is incredible and after reading your post I was wondering if it would be worth moving the handle down the bow to decrease this shock.
Good questions too Daniel. I'm sure it's not only you and I who are learning from this thread.
Regards.
Oliver.
"Archery may not be the sport of kings. But it is definitely the KING OF SPORTS."-Howard Hill
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Dennis La Varenne
- Posts: 1776
- Joined: Sun Sep 07, 2003 10:56 pm
- Location: Tocumwal, NSW. Australia
Oliver,
Without examining your bow, it is difficult to make firm judgements. Use of heavier arrows is the easiest way to calm things down, followed by narrowing the tips and reducing their mass.
The commonest cause of hand shock is limbs which are out of time because of different stiffness in either limb. The trick is to get them back to the same stiffness so they recoil at the same speed.
In relation to my advice to Daniel, try drawing your bow back on a tiller and checking the angles of the string above and below the present arrow line, then moving the tiller up and down the handle by small amounts to see which position gives the most equal string angles, then try shooting your arrow from that position.
I have attached a diagram of a tiller and a bow drawn on one in case you have not seen one. It is not a difficult tool to make from a piece of board.
If this cures the problem of excessive handshock, then you can re-make your handle with the arrow shelf at that position.
Dennis La Varenne
Without examining your bow, it is difficult to make firm judgements. Use of heavier arrows is the easiest way to calm things down, followed by narrowing the tips and reducing their mass.
The commonest cause of hand shock is limbs which are out of time because of different stiffness in either limb. The trick is to get them back to the same stiffness so they recoil at the same speed.
In relation to my advice to Daniel, try drawing your bow back on a tiller and checking the angles of the string above and below the present arrow line, then moving the tiller up and down the handle by small amounts to see which position gives the most equal string angles, then try shooting your arrow from that position.
I have attached a diagram of a tiller and a bow drawn on one in case you have not seen one. It is not a difficult tool to make from a piece of board.
If this cures the problem of excessive handshock, then you can re-make your handle with the arrow shelf at that position.
Dennis La Varenne
- Attachments
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- Tiller-stick.jpg (43.47 KiB) Viewed 4351 times
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- Bowstave-on-tiller.jpg (21.84 KiB) Viewed 4351 times
Dennis La Varénne
Have the courage to argue your beliefs with conviction, but the humility to accept that you may be wrong.
QVIS CVSTODIET IPSOS CVSTODES (Who polices the police?) - DECIMVS IVNIVS IVVENALIS (Juvenal) - Satire VI, lines 347–8
What is the difference between free enterprise capitalism and organised crime?
HOMO LVPVS HOMINIS - Man is his own predator.
Have the courage to argue your beliefs with conviction, but the humility to accept that you may be wrong.
QVIS CVSTODIET IPSOS CVSTODES (Who polices the police?) - DECIMVS IVNIVS IVVENALIS (Juvenal) - Satire VI, lines 347–8
What is the difference between free enterprise capitalism and organised crime?
HOMO LVPVS HOMINIS - Man is his own predator.
-
Running Bear Eagle Eye
- Posts: 78
- Joined: Fri Jul 28, 2006 4:56 pm
- Location: Melbourne
Thanks for the answers so far.
I have another question today i went and bought some spotted gum which i will try and turn into some sort of a bow. While looking for it i noticed that the spotted gum is a darker more red colour than the usual lighter colour that i normally get.
Is there any reason why also ive heard that spotted gum isnt any good if it is from some places in Australia do.
Do you think that spotted gum from melbourne wood suppliers would be using the wrong type.
Thanks
Daniel
I have another question today i went and bought some spotted gum which i will try and turn into some sort of a bow. While looking for it i noticed that the spotted gum is a darker more red colour than the usual lighter colour that i normally get.
Is there any reason why also ive heard that spotted gum isnt any good if it is from some places in Australia do.
Do you think that spotted gum from melbourne wood suppliers would be using the wrong type.
Thanks
Daniel
Hi Daniel,
You must remember that the timber supply companies are providing a product for the housing and construction industry. I was down at my source of supply today and to my dismay they had run out of a suitable supply of spotted gum over Christmas. I have built up a repore with the gentleman (he knows what I require) who runs the timber side of the business and over the next few days he will sort through their remaiming stock of spotted gum to try to find some suitable boards. For laminations I have found the darker red is better as some of the greyer wood is too close to the late growth and tends to be unstable. Once again locality would have a bearing.
Daryl.
You must remember that the timber supply companies are providing a product for the housing and construction industry. I was down at my source of supply today and to my dismay they had run out of a suitable supply of spotted gum over Christmas. I have built up a repore with the gentleman (he knows what I require) who runs the timber side of the business and over the next few days he will sort through their remaiming stock of spotted gum to try to find some suitable boards. For laminations I have found the darker red is better as some of the greyer wood is too close to the late growth and tends to be unstable. Once again locality would have a bearing.
Daryl.
"And you must not stick for a groat or twelvepence more than another man would give, if it be a good bow.
For a good bow twice paid for, is better than an ill bow once broken. [Ascham]
“If a cluttered desk is a sign of a cluttered mind, of what, then, is an empty desk a sign?” [Einstein]
I am old enough to make my own decisions....Just not young enough to remember what I decided!....
For a good bow twice paid for, is better than an ill bow once broken. [Ascham]
“If a cluttered desk is a sign of a cluttered mind, of what, then, is an empty desk a sign?” [Einstein]
I am old enough to make my own decisions....Just not young enough to remember what I decided!....
-
Dennis La Varenne
- Posts: 1776
- Joined: Sun Sep 07, 2003 10:56 pm
- Location: Tocumwal, NSW. Australia
Daniel,
Greybeard is right about the location of the source of Spotted Gum. There is nothing wrong with it as a bow wood at all. Glenn Newell was probably most responsible for making us aware of its worth as a bow wood.
I am from Melbourne too. The Spotted Gum we get down here is a much lighter variety - both colour and density. That from coastal Queensland is often nearly chocolate in colour or darker reddish brown and much more dense and stronger. It may even be better again from inland Queensland.
You are probably getting the southern species of Spotted Gum, which, being less dense means you have got to make the dimensions of your bow a smidgeon larger for the same draw weight, that's all.
On average, less dense woods have a lower modulus of elasticity which means they recoil at a slower rate than the more dense woods and hence generate a bit lower arrow speeds. That just means you get a few paces closer to the game.
Dennis La Varenne
PS: Daryl, get a patent on that take-down design as quick as you can or the Yanks will take if from you.
Greybeard is right about the location of the source of Spotted Gum. There is nothing wrong with it as a bow wood at all. Glenn Newell was probably most responsible for making us aware of its worth as a bow wood.
I am from Melbourne too. The Spotted Gum we get down here is a much lighter variety - both colour and density. That from coastal Queensland is often nearly chocolate in colour or darker reddish brown and much more dense and stronger. It may even be better again from inland Queensland.
You are probably getting the southern species of Spotted Gum, which, being less dense means you have got to make the dimensions of your bow a smidgeon larger for the same draw weight, that's all.
On average, less dense woods have a lower modulus of elasticity which means they recoil at a slower rate than the more dense woods and hence generate a bit lower arrow speeds. That just means you get a few paces closer to the game.
Dennis La Varenne
PS: Daryl, get a patent on that take-down design as quick as you can or the Yanks will take if from you.
Dennis La Varénne
Have the courage to argue your beliefs with conviction, but the humility to accept that you may be wrong.
QVIS CVSTODIET IPSOS CVSTODES (Who polices the police?) - DECIMVS IVNIVS IVVENALIS (Juvenal) - Satire VI, lines 347–8
What is the difference between free enterprise capitalism and organised crime?
HOMO LVPVS HOMINIS - Man is his own predator.
Have the courage to argue your beliefs with conviction, but the humility to accept that you may be wrong.
QVIS CVSTODIET IPSOS CVSTODES (Who polices the police?) - DECIMVS IVNIVS IVVENALIS (Juvenal) - Satire VI, lines 347–8
What is the difference between free enterprise capitalism and organised crime?
HOMO LVPVS HOMINIS - Man is his own predator.
-
Running Bear Eagle Eye
- Posts: 78
- Joined: Fri Jul 28, 2006 4:56 pm
- Location: Melbourne
Thanks again guys
I think this is the last few question before i start building my bow unless i can come across anymore during consruction.
Im wondering how everyone makes their laminations do you just plane them down with an electric planer.
Has anyone tried using one of those planer thicknesser machines which you just insert the wood and it comes out perfectley even( I think)
How do you tiller a laminated bow im thinking of making a two spotted gum laminated core with a bamboo belly and back, to tiller it do i make the laminations different thicknesses from handle to tips or do i just change the width of the limbs from handle to tips.
Thanks
Daniel
I think this is the last few question before i start building my bow unless i can come across anymore during consruction.
Im wondering how everyone makes their laminations do you just plane them down with an electric planer.
Has anyone tried using one of those planer thicknesser machines which you just insert the wood and it comes out perfectley even( I think)
How do you tiller a laminated bow im thinking of making a two spotted gum laminated core with a bamboo belly and back, to tiller it do i make the laminations different thicknesses from handle to tips or do i just change the width of the limbs from handle to tips.
Thanks
Daniel
Hi Daniel,
Regarding the electric planer or thicknesser both are less useful than an ashtray on a motorbike or a shirt without a pocket. If you are looking at milled boards 19mm thick and want to reduce them to say 2mm unless you can reduce them through a saw first you will have 17mm going out as shavings. Planers and thicknessing machines are savage and rip out any wayward wood fibres in a grain change. If you can get a decent lamination out of one of these machines you then have to groove the surfaces to obtain strong glue lines as these machines leave the surfaces too smooth. All of my bamboo back and belly bows use parallel laminations and the tiller of the bow is determined by the plan of the bow and the taper obtained by shaping the bamboo before it is glued to the core. To save going into lengthy detail in this post click into my profile and check my previous posts. There are a few that explain the process. If you want more information and photos please send me a pm.
Daryl.
Regarding the electric planer or thicknesser both are less useful than an ashtray on a motorbike or a shirt without a pocket. If you are looking at milled boards 19mm thick and want to reduce them to say 2mm unless you can reduce them through a saw first you will have 17mm going out as shavings. Planers and thicknessing machines are savage and rip out any wayward wood fibres in a grain change. If you can get a decent lamination out of one of these machines you then have to groove the surfaces to obtain strong glue lines as these machines leave the surfaces too smooth. All of my bamboo back and belly bows use parallel laminations and the tiller of the bow is determined by the plan of the bow and the taper obtained by shaping the bamboo before it is glued to the core. To save going into lengthy detail in this post click into my profile and check my previous posts. There are a few that explain the process. If you want more information and photos please send me a pm.
Daryl.
"And you must not stick for a groat or twelvepence more than another man would give, if it be a good bow.
For a good bow twice paid for, is better than an ill bow once broken. [Ascham]
“If a cluttered desk is a sign of a cluttered mind, of what, then, is an empty desk a sign?” [Einstein]
I am old enough to make my own decisions....Just not young enough to remember what I decided!....
For a good bow twice paid for, is better than an ill bow once broken. [Ascham]
“If a cluttered desk is a sign of a cluttered mind, of what, then, is an empty desk a sign?” [Einstein]
I am old enough to make my own decisions....Just not young enough to remember what I decided!....
Hi Daniel,
Making laminations can be a real pain, particularly if you do not have suitable equipment to produce them. If you have access to a half decent bandsaw through friends, relatives etc this may be a start. Alternatively check the yellow pages as there are businesses that have fully equipped wood working shops. You supply the material they supply the equipment. The one in Brisbane is called ‘Wood N’ You’. They have a scale of charges depending on the machine used and time. If you are not competent with a particular machine they will do it for you at an additional charge. This could be a relatively cheap alternative to buying the necessary equipment.
I have included two photos of a student preparing laminations at current bow making workshop.
The third photo is of the lower limb near the handle of a bamboo back and belly bow (not one of mine) using a single core. The radical grain change was probably overpowered by the bamboo and now has a permanent set. With multiple laminations you can end for end or step the laminations to minimise weak spots.
Daryl.
Making laminations can be a real pain, particularly if you do not have suitable equipment to produce them. If you have access to a half decent bandsaw through friends, relatives etc this may be a start. Alternatively check the yellow pages as there are businesses that have fully equipped wood working shops. You supply the material they supply the equipment. The one in Brisbane is called ‘Wood N’ You’. They have a scale of charges depending on the machine used and time. If you are not competent with a particular machine they will do it for you at an additional charge. This could be a relatively cheap alternative to buying the necessary equipment.
I have included two photos of a student preparing laminations at current bow making workshop.
The third photo is of the lower limb near the handle of a bamboo back and belly bow (not one of mine) using a single core. The radical grain change was probably overpowered by the bamboo and now has a permanent set. With multiple laminations you can end for end or step the laminations to minimise weak spots.
Daryl.
- Attachments
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- Grain Change In Single Lamination.jpg (12.31 KiB) Viewed 4181 times
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- Student Grinding Lamination To Thickness.jpg (33.18 KiB) Viewed 4181 times
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- Student Cutting Lamination From Board.jpg (28.65 KiB) Viewed 4181 times
"And you must not stick for a groat or twelvepence more than another man would give, if it be a good bow.
For a good bow twice paid for, is better than an ill bow once broken. [Ascham]
“If a cluttered desk is a sign of a cluttered mind, of what, then, is an empty desk a sign?” [Einstein]
I am old enough to make my own decisions....Just not young enough to remember what I decided!....
For a good bow twice paid for, is better than an ill bow once broken. [Ascham]
“If a cluttered desk is a sign of a cluttered mind, of what, then, is an empty desk a sign?” [Einstein]
I am old enough to make my own decisions....Just not young enough to remember what I decided!....
Grahame,
Now that you have brought it to my attention it does look like him.
Daryl.
Now that you have brought it to my attention it does look like him.
Daryl.
"And you must not stick for a groat or twelvepence more than another man would give, if it be a good bow.
For a good bow twice paid for, is better than an ill bow once broken. [Ascham]
“If a cluttered desk is a sign of a cluttered mind, of what, then, is an empty desk a sign?” [Einstein]
I am old enough to make my own decisions....Just not young enough to remember what I decided!....
For a good bow twice paid for, is better than an ill bow once broken. [Ascham]
“If a cluttered desk is a sign of a cluttered mind, of what, then, is an empty desk a sign?” [Einstein]
I am old enough to make my own decisions....Just not young enough to remember what I decided!....
-
Running Bear Eagle Eye
- Posts: 78
- Joined: Fri Jul 28, 2006 4:56 pm
- Location: Melbourne
Thanks Darryl
I have a little 10 inch bansaw which i used to gut the 2 19mm thick board into three thin pieces of about 4-5mm.
I dont have one of those grinding machines so i decided to give the electric planer a go. I set it to the lowest setting and took a tiny bit off each lamination and then i scratched up the surfaces of the limbs to give the glue something to hold to.
I decided to just use two spotted gum laminations for the core of each limb and bamboo for the backing and im still undecided on whether to put anything on the belly, but i might put a thin piece of bamboo on the belly
Ive glued the handle and both limbs together but at the moment ive only glued the spotted gum cores to the handle.
As for bamboo im thinking of just going to bunnings and buying one of those bamboo poles however i have alot of large bamboo plants close to my house, how long do i have to leave the bamboo to dry once i cut it down?
Thanks for the responses so far.
Daniel
I have a little 10 inch bansaw which i used to gut the 2 19mm thick board into three thin pieces of about 4-5mm.
I dont have one of those grinding machines so i decided to give the electric planer a go. I set it to the lowest setting and took a tiny bit off each lamination and then i scratched up the surfaces of the limbs to give the glue something to hold to.
I decided to just use two spotted gum laminations for the core of each limb and bamboo for the backing and im still undecided on whether to put anything on the belly, but i might put a thin piece of bamboo on the belly
Ive glued the handle and both limbs together but at the moment ive only glued the spotted gum cores to the handle.
As for bamboo im thinking of just going to bunnings and buying one of those bamboo poles however i have alot of large bamboo plants close to my house, how long do i have to leave the bamboo to dry once i cut it down?
Thanks for the responses so far.
Daniel
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longbow steve
- Posts: 3116
- Joined: Tue Jan 30, 2007 3:29 pm
- Location: BLUE MOUNTAINS
Hi Rbee, With regard to bamboo seasoning, large poles can take 12 months or more, the beauty of it is it can be monitored by its colour.
I allow mine to settle/dry for a couple of months then remove the internodes internally to allow for better air flow in the pole. Keep it inside or under good cover.
I have found the best poles to use are those boiled in Hydrogen pyroxide, the poles from Bunnings may have mould inside but good results can be had with these if the look of them is not of concern. Contact Bamboo Australia for bleached poles. Steve
I allow mine to settle/dry for a couple of months then remove the internodes internally to allow for better air flow in the pole. Keep it inside or under good cover.
I have found the best poles to use are those boiled in Hydrogen pyroxide, the poles from Bunnings may have mould inside but good results can be had with these if the look of them is not of concern. Contact Bamboo Australia for bleached poles. Steve
Daniel,
I am a little unsure of the way in which you are constructing the bow. From your previous post it looks like you are using a butt joint of the laminations on the handle.
Some factors that determine the finished product are the length of the bow, width of the limbs at the fadeouts and string nocks as well as the length of the handle? Are you laying the bow up flat or using a form to build in reflex. Also what draw weight are you trying to achieve.
I don’t wish to bombard you with questions but these details are relevant when building a laminated bow.
The following statistics produced a 40# bow @28â€Â. The length of bow n’ to n’ is 60â€Â, the handle section being 11â€Â. Original reflex built in was 3’’ but settled at 1†after shooting in.
Two laminations of spotted gum each 2.5 mm thick were used for the core with Moso bamboo back and belly.
The finished bow is 1 ¼†wide at the fadeouts and 5/8†at the string nocks. Limb thickness is 11 mm at fadeouts and 8 mm before tip overlays.
Hopefully these figures will give you a bit of a guide.
Irrespective of the final outcome of you bow enjoy the challenge and you will learn some valuable lessons.
Best of luck,
Daryl.
I am a little unsure of the way in which you are constructing the bow. From your previous post it looks like you are using a butt joint of the laminations on the handle.
Some factors that determine the finished product are the length of the bow, width of the limbs at the fadeouts and string nocks as well as the length of the handle? Are you laying the bow up flat or using a form to build in reflex. Also what draw weight are you trying to achieve.
I don’t wish to bombard you with questions but these details are relevant when building a laminated bow.
The following statistics produced a 40# bow @28â€Â. The length of bow n’ to n’ is 60â€Â, the handle section being 11â€Â. Original reflex built in was 3’’ but settled at 1†after shooting in.
Two laminations of spotted gum each 2.5 mm thick were used for the core with Moso bamboo back and belly.
The finished bow is 1 ¼†wide at the fadeouts and 5/8†at the string nocks. Limb thickness is 11 mm at fadeouts and 8 mm before tip overlays.
Hopefully these figures will give you a bit of a guide.
Irrespective of the final outcome of you bow enjoy the challenge and you will learn some valuable lessons.
Best of luck,
Daryl.
"And you must not stick for a groat or twelvepence more than another man would give, if it be a good bow.
For a good bow twice paid for, is better than an ill bow once broken. [Ascham]
“If a cluttered desk is a sign of a cluttered mind, of what, then, is an empty desk a sign?” [Einstein]
I am old enough to make my own decisions....Just not young enough to remember what I decided!....
For a good bow twice paid for, is better than an ill bow once broken. [Ascham]
“If a cluttered desk is a sign of a cluttered mind, of what, then, is an empty desk a sign?” [Einstein]
I am old enough to make my own decisions....Just not young enough to remember what I decided!....
-
Running Bear Eagle Eye
- Posts: 78
- Joined: Fri Jul 28, 2006 4:56 pm
- Location: Melbourne
First of all thanks steve, also does the mould effect the durability and strength of the bamboo or is just the looks.
Daryl
im also unsure of how im building the bow so your not alone there.
My bow is 58inches long tip to tip. I havent done the nocks yet.
it has a 12inch handle and is 4cm wide at the fade outs and 2cm at the tips.
The limbs core is two laminations of spotted gum which is 3.5mm thick each. So the limbs so far is 7mm thick at the fadeouts and the same at the tips.
I am unsure of how much to take off the thickness of the limbs so i was planning on putting on the bamboo backing and then bending the bow a little bit and slowly working out how thick the limbs need to be for it ti bend evenly.
As for poundage of the bow i really have no idea what im going to get i would prefer something of around 50-60 pounds but i will be just as happy with a bow of any weight that works.
Would you recommend i put on a belly of bamboo and if so how thick.
I will try and get some photos of the bow so far but ive lost the bit that connects the camera to the computer to take the pictures off it.
Daniel
Daryl
im also unsure of how im building the bow so your not alone there.
My bow is 58inches long tip to tip. I havent done the nocks yet.
it has a 12inch handle and is 4cm wide at the fade outs and 2cm at the tips.
The limbs core is two laminations of spotted gum which is 3.5mm thick each. So the limbs so far is 7mm thick at the fadeouts and the same at the tips.
I am unsure of how much to take off the thickness of the limbs so i was planning on putting on the bamboo backing and then bending the bow a little bit and slowly working out how thick the limbs need to be for it ti bend evenly.
As for poundage of the bow i really have no idea what im going to get i would prefer something of around 50-60 pounds but i will be just as happy with a bow of any weight that works.
Would you recommend i put on a belly of bamboo and if so how thick.
I will try and get some photos of the bow so far but ive lost the bit that connects the camera to the computer to take the pictures off it.
Daniel
Hi Daniel,
From the figures you have given I think the bow will be way over built. You must remember that when using bamboo on a bow the diameter of the pole will have a bearing on the height of the crown of the bamboo in relation of the width of the limbs. A limb width of 30mm at the fadeouts and 15mm at the tips may be more suitable. Remember to profile the bamboo to the plan of the bow. Depending on the characteristics of the spotted gum it may be advisable to reduce the core to about 5mm.
Because the bow is 58 inches overall you will probably end up at 56 inches nock to nock. Allowing for a 12 inch handle you are left with 22 inches on each limb to do the work.
I would recommend using bamboo on the belly of the bow but once again the thickness of the bamboo will be governed by pole diameter and limb width. The crown of the bamboo can be reduced a little but do not remove too much of the power fibres.
I hope this information helps but remember it is my appraisal of the situation and that the suggestions may be of assistance.
Daryl.
From the figures you have given I think the bow will be way over built. You must remember that when using bamboo on a bow the diameter of the pole will have a bearing on the height of the crown of the bamboo in relation of the width of the limbs. A limb width of 30mm at the fadeouts and 15mm at the tips may be more suitable. Remember to profile the bamboo to the plan of the bow. Depending on the characteristics of the spotted gum it may be advisable to reduce the core to about 5mm.
Because the bow is 58 inches overall you will probably end up at 56 inches nock to nock. Allowing for a 12 inch handle you are left with 22 inches on each limb to do the work.
I would recommend using bamboo on the belly of the bow but once again the thickness of the bamboo will be governed by pole diameter and limb width. The crown of the bamboo can be reduced a little but do not remove too much of the power fibres.
I hope this information helps but remember it is my appraisal of the situation and that the suggestions may be of assistance.
Daryl.
"And you must not stick for a groat or twelvepence more than another man would give, if it be a good bow.
For a good bow twice paid for, is better than an ill bow once broken. [Ascham]
“If a cluttered desk is a sign of a cluttered mind, of what, then, is an empty desk a sign?” [Einstein]
I am old enough to make my own decisions....Just not young enough to remember what I decided!....
For a good bow twice paid for, is better than an ill bow once broken. [Ascham]
“If a cluttered desk is a sign of a cluttered mind, of what, then, is an empty desk a sign?” [Einstein]
I am old enough to make my own decisions....Just not young enough to remember what I decided!....
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longbow steve
- Posts: 3116
- Joined: Tue Jan 30, 2007 3:29 pm
- Location: BLUE MOUNTAINS
Hi, Mostly the mould stains the bamboo, I mainly use mine as ground laminations under clear glass so I discard any that are stained.
I would inspect any mould affected bamboo, see whether the black discoulouration has penetrated the core, mostly it is cosmetic but just like any mouldy or moisture affected timber it should be approached with weakness in mind, do some bend tests of affected and unaffected bamboo taking note of consistency etc.
If you are planning on putting a stained finish on the bow minor blemishes may just add to its character. Steve
I would inspect any mould affected bamboo, see whether the black discoulouration has penetrated the core, mostly it is cosmetic but just like any mouldy or moisture affected timber it should be approached with weakness in mind, do some bend tests of affected and unaffected bamboo taking note of consistency etc.
If you are planning on putting a stained finish on the bow minor blemishes may just add to its character. Steve
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Running Bear Eagle Eye
- Posts: 78
- Joined: Fri Jul 28, 2006 4:56 pm
- Location: Melbourne
I recentley too the bow out of the clamps after putting on the bamboo laminations, I took daryls advice and thinned the limbs to 30mm at the fades and 15 at the tips however in the excitement of putting the belly laminations on i forgot to thin down the core and even though im yet to put it on the tiller stick i would guess the bows around 90pds or more.
For that reason i doubt this bow will work but after putting so many days work into it atleast want to see how far i can get it to draw to before the heart breaking crack sounds.
However im thinking of wrapping critical parts of the limb in some sort of string like what is used on the horsebows, do you think this will strengthen them or is it just a waste of time.
Ive been looking around the house and all i can find is cotton do you think this will work.
Im not to sure of the procedure of wrapping the limbs i think i read somewhere that you need to wet the tring so that it drys and shrinks to clamp down on the wood better, any way so any info on this subject would be greatley appreciated.
Thanks
Daniel
For that reason i doubt this bow will work but after putting so many days work into it atleast want to see how far i can get it to draw to before the heart breaking crack sounds.
However im thinking of wrapping critical parts of the limb in some sort of string like what is used on the horsebows, do you think this will strengthen them or is it just a waste of time.
Ive been looking around the house and all i can find is cotton do you think this will work.
Im not to sure of the procedure of wrapping the limbs i think i read somewhere that you need to wet the tring so that it drys and shrinks to clamp down on the wood better, any way so any info on this subject would be greatley appreciated.
Thanks
Daniel
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longbow steve
- Posts: 3116
- Joined: Tue Jan 30, 2007 3:29 pm
- Location: BLUE MOUNTAINS
Hi, all may not be lost with regard to not thinning the belly lamination, some other guys may correct me but I believe the bamboo on the belly may be thinned quite a bit to give you the tiller required without risk of failure. It is not as critical to maintain the power fibres in compression as it is in tension as far as I know. I have one bow that I have reduced the belly bamboo without failure and have seen Keith Keddie of Aruacaria do the same on some/all? of his bows. Please comment others if I am misinformed. Steve