Degame Danish Flat Bow [Holmegaard / Mollegabet]

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greybeard
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Degame Danish Flat Bow [Holmegaard / Mollegabet]

#1 Post by greybeard » Fri Jan 30, 2015 3:45 pm

To date Degame is proving to be a good timber for bows of different cross sections.

The third bow in this test is a Danish flat bow [Holmegaard / Mollegabet].

Dimensions are; 68” n to n, each working limb length 15 ½”, width at widest point 1 5/8” and a touch over 9/16” thick, and at narrowest 1 ¼” and a touch over 7/16” thick.

Rigid tip length from top of neck to nock is 11”.

As I make more of these bows I am gradually reducing the thickness of the non working section of the limbs.

Considering the short working limbs with a total length of 31” and the thickness of the limbs the bow settled at a disappointing 40# @ 28”.

Perhaps I am used to the results obtained from hickory and hard rock maple.
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In summing up on the progress to date I believe that Degame [lemonwood] would be an excellent choice for the first time bowyer, the reasons being that grain orientation does not appear to be an issue, handles compression well, is an easy timber to work with hand tools and is moderately priced.

Early indications suggest that Degame is very consistent down its length and if a stave is worked to fine tolerances the tiller will virtually be zero.

The only downside at present is availability unless you reside in the Logan / Beenleigh area.

Care must be taken when using 40 to 60 grit paper, only use coarse grit in the preliminary sanding otherwise you will have difficulty removing the scratches in the final sanding stages.

Degame readily accepts wipe on finishes such as Minwax Poly.


For final testing I will produce a bamboo backed Degame longbow.

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!....

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Re: Degame Danish Flat Bow [Holmegaard / Mollegabet]

#2 Post by bigbob » Fri Jan 30, 2015 5:11 pm

gee Daryl You gazzumped me with your post! :biggrin: I have been working on a hickory mollegebet as well. slightly different dimensions, but I will be very happy if i can get the same result as yours. Very nice looking bow. I had hoped not to back mine but when shaping one working limb the grain run out quite markedly so even allowing for hickory's apparent tolerance to grain violation decided to use hessian as backing and hopefully ensure a working bow.I z spliced the two billets and added a little osage on the back of handle as extra insurance.Here's a couple of shots of some progress.I will add some more shots later. Just realised I should have started another thread as it seems I've hijacked yours :oops: :oops:
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Re: Degame Danish Flat Bow [Holmegaard / Mollegabet]

#3 Post by Gringa Bows » Fri Jan 30, 2015 7:10 pm

Great job Daryl as always mate

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Re: Degame Danish Flat Bow [Holmegaard / Mollegabet]

#4 Post by greybeard » Sat Jan 31, 2015 11:49 am

Bob and Rod, thank you, I am enjoying making wooden bows it’s a nice change and challenge from the glass laminates.

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!....

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Re: Degame Danish Flat Bow [Holmegaard / Mollegabet]

#5 Post by Hamish » Tue Feb 03, 2015 10:54 am

Lovely!

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Re: Degame Danish Flat Bow [Holmegaard / Mollegabet]

#6 Post by Nezwin » Tue Feb 03, 2015 5:45 pm

Very nice bow, again, Daryl! I look forward to your next experiment in Degame and the results you might achieve when the shipment comes in later this month with properly processed boards.

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Re: Degame Danish Flat Bow [Holmegaard / Mollegabet]

#7 Post by Stickbow Hunter » Tue Feb 03, 2015 6:04 pm

Great work once again Daryl.

Jeff

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Re: Degame Danish Flat Bow [Holmegaard / Mollegabet]

#8 Post by greybeard » Tue Feb 10, 2015 3:38 pm

Nezwin wrote:......I look forward to your next experiment in Degame and the results you might achieve when the shipment comes in later this month with properly processed boards.
'Bow Woods and Bow Staves' in the book by By L. E. Stemmler, 1942.

"LEMONWOOD (Calycophyllum candidissimum), the degame of the wood importers, is a native of Cuba. It is hard, heavy, tough and springy. It comes in small logs or spars and is straight enough to be sawn into bow staves. It is the most satisfactory and reasonably priced wood of which to make a bow. It grows in the mountains, and most of it is carted by oxen to a port for shipment by steamer. The bark is a reddish brown, rather stringy and somewhat resembles red cedar bark. It has nothing to do with lemons; the name refers to its colour. It varies from a light yellow to a light brown and is often mottled. We have found that the spars yielding the very best bow staves have a distinct apple green streak just under the bark. Lemonwood is a true bow wood, and for an all-around bow, as good as any that comes. The fact that the highest score ever made in tournament for the American Round was made with a lemonwood bow speaks well for its qualities."

Perhaps through logging and milling the timber most suited to the bowyer is being wasted. Tree size; 40-80 ft (12-24 m) tall, 1-2 ft (.3-.6 m) trunk diameter.

Irrespective of the above I will purchase some milled boards as I believe backing with pole bamboo will negate the minor issues I have with Degame.

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!....

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Re: Degame Danish Flat Bow [Holmegaard / Mollegabet]

#9 Post by Dennis La Varenne » Sat Feb 14, 2015 9:54 pm

Daryl,

You have got the Mollegabet/Holmegaard tiller down pat with this bow. It is exactly what I was describing in my paper on the style. I have seen a great number of what purports to be a bow of this style by makers in the US and they all get the tiller wrong. The side tapers vary considerably in the proportions between length of the outer levers and the inner working limb which are far from resembling the original artifact, but consistently get the tiller completely wrong or have end levers which are massive.

Congratulations on a fine job. It is an instruction to all who would wish to attempt the style.
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.

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Re: Degame Danish Flat Bow [Holmegaard / Mollegabet]

#10 Post by greybeard » Mon Feb 16, 2015 7:52 am

Dennis, thank you for your comments.

I believe that a little more mass could be shed from the outer limbs without jeopardising the bows integrity or comprising the design or function of the bow.

From a tillering point of view this design is relatively easy if worked to accurate measurements.

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!....

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Re: Degame Danish Flat Bow [Holmegaard / Mollegabet]

#11 Post by Dennis La Varenne » Mon Feb 16, 2015 5:26 pm

Daryl,

Last time I made one, I thickness taper the levers to be the same as limb thickness at the shoulders and tapering in a straight line to the outer tips with no step on the belly side as you have done. The levers still did not want to bend because of the reverse thickness taper because as they narrowed toward the tip, they also increased in thickness.

I was trying to keep the lever to as low a mass as I could. This is just my idea of course, but the Americans seem to like to put crowbars on the end of their Mollegabets I notice. Most of their wood bows seem to exaggerate all their features for some reason - a bit like their slapstick comedy - just in case you don't notice it.
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.

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Re: Degame Danish Flat Bow [Holmegaard / Mollegabet]

#12 Post by sylakone » Thu Feb 26, 2015 7:33 am

Hi Guys

Beautiful bow.

I am actually about to start making a bow in this style with spotted Gum.
What would you suggest be the measurements for spotted game same max width 1 5/8th or wider?
I am trying for 68" n-n the build alongs I have watched were an american design which wanted to go for 2.5" wide which seems a lot.

Any tips would be great.

Thanks

Sy
Cheers

Sy

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Re: Degame Danish Flat Bow [Holmegaard / Mollegabet]

#13 Post by Dennis La Varenne » Thu Feb 26, 2015 2:51 pm

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.

However, in modern times we have accepted that they did exist and make bows based on that concept. Whatever the reality was in Neolithic times, the design with shoulders and non-bending outer levers definitely has bowmaking merit, but they are tricky to get right. We also tend to have deeper handles on ours than the originals do.

Anyway, here is the schematic with some measurements. Europeans use a comma instead of a point for decimals like we do just in case the measurements look a bit strange.
Holmegrdkopi-1.jpg
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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.

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Re: Degame Danish Flat Bow [Holmegaard / Mollegabet]

#14 Post by greybeard » Thu Feb 26, 2015 4:03 pm

sylakone wrote:...I am actually about to start making a bow in this style with spotted Gum...
Sy,

The length of the bows that have been found range from 61 inches long x 1 25/32” width up to 76 inches long and 2 11/32” in width.

Evidence would suggest that the bows were made from saplings rather than staves being split from large logs.

If this is your first attempt at this style of bow I would suggest going 68 to 70 inches n to n depending on your draw length and poundage and up to 2 inches at the widest.

Check the spotted gum for any signs of sap tunnels as these can cause the bow to fail.

Alan Jones produced this ironbark bow which shares the same tillering technique as the Holmegaard.
Ironbark Bow.jpg
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Another bow from the area;

http://www.buewesth.dk/ringkloster_buen_e.html

Compare the mechanical properties of the two timbers and you should realise the need for design modification.

[Properties of the gum could differ depending on which variety you have]

Common Name(s): Spotted Gum
Scientific Name: Corymbia maculata (syn. Eucalyptus maculata)
Distribution: Australia (coastal regions of New South Wales)
Tree Size: 100-165 ft (30-50 m) tall, 3-5 ft (1-1.5 m) trunk diameter
Average Dried Weight: 59 lbs/ft3 (940 kg/m3)
Specific Gravity (Basic, 12% MC): .71, .94
Janka Hardness: 2,330 lbf (10,360 N)
Modulus of Rupture: 20,550 lbf/in2 (141.8 MPa)
Elastic Modulus: 2,867,000 lbf/in2 (19.77 GPa)
Crushing Strength: 10,410 lbf/in2 (71.8 MPa)
Shrinkage: Radial: 6.3%, Tangential: 9.9%, Volumetric: 16.3%, T/R Ratio: 1.6

Common Name(s): Dutch Elm
Scientific Name: Ulmus × hollandica (Dutch Elm is a European elm hybrid, coming from U. glabra x U. minor and/or a variety of other species)
Distribution: Europe
Tree Size: 80-115 ft (25-35 m) tall, 3-5 ft (1-1.5 m) trunk diameter
Average Dried Weight: 36 lbs/ft3 (575 kg/m3)
Specific Gravity (Basic, 12% MC): .48, .58
Janka Hardness: 850 lbf (3,790 N)
Modulus of Rupture: 9,960 lbf/in2 (68.7 MPa)
Elastic Modulus: 1,091,000 lbf/in2 (7.52 GPa)
Crushing Strength: 4,640 lbf/in2 (32.0 MPa)
Shrinkage:No data available (Most likely very similar to other species in the Ulmus genus)
Flemming Alrune Holmegaard Bow.jpg
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Holmegaard Dimensions.jpg
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A Bowmaker's Tribute To the English Elm.pdf
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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!....

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Re: Degame Danish Flat Bow [Holmegaard / Mollegabet]

#15 Post by sylakone » Thu Feb 26, 2015 6:03 pm

Thanks guys

I think I will try to copy the dimensions you put up greybeard with alterations to make the full 68" or 70" n - n.
My draw weight at the moment is between #30-#40 and my draw length is around 29".

That will help a lot I am surprised how low the dutch elm specs are compared to most other bow woods.

Cheers

Sy
Cheers

Sy

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Re: Degame Danish Flat Bow [Holmegaard / Mollegabet]

#16 Post by greybeard » Thu Feb 26, 2015 8:32 pm

sylakone wrote:....That will help a lot I am surprised how low the dutch elm specs are compared to most other bow woods......
This is why you can't generally use the dimensions of northern hemisphere timbered bows when using Australian hardwoods.

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!....

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Re: Degame Danish Flat Bow [Holmegaard / Mollegabet]

#17 Post by Dennis La Varenne » Fri Feb 27, 2015 12:21 pm

greybeard wrote: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 supplied, the MoR for Spotted Gum is almost 2x that of Elm. So you could expect a same sized bow from Spotted Gum to be almost the same proportions in draw weight too. I found that out when substituting Osage for Elm a long time ago.

I should have said that in my post above.
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.

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Re: Degame Danish Flat Bow [Holmegaard / Mollegabet]

#18 Post by sylakone » Fri Feb 27, 2015 9:06 pm

So I will need to look at making the working limbs almost half the thickness?

Cheers

Sy
Cheers

Sy

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Re: Degame Danish Flat Bow [Holmegaard / Mollegabet]

#19 Post by Dennis La Varenne » Fri Feb 27, 2015 10:15 pm

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 to the original will have twice the draw weight, but -
2. A bow which is made twice as thick where every other dimension is equal to the original will be 8 times the draw weight.

When you are progressively reducing or 'sinking', the draw weight of your bowstave as it is called in bowmaking, you keep testing its draw weight often by drawing it out on your tiller. However, you NEVER draw it more than the draw weight you wish it to finish at.

As well as frequently checking and refining the bend in the limbs, at each stage, you must also check its draw weight at that stage, being careful not to bend it so far that your scale shows more than its intended draw weight even if that is only half the way to full draw. It is called the Jim Hamm technique because it was first published by an American bloke of that name.

Remember, you are making a Holmegaard STYLED bow, not a copy of the original which is a replica, so it only has to be a fair look alike.

Also, as Daryl pointed out above, the original was made from a small diameter sapling with the belly being the inside of the split and the rounded underbark surface as the back. You will be making yours from milled timber most probably, but if you are a Queenslander and can get hold of a small Soapwood or Red Ash (Alphitonia excelsa) sapling of around 4 to 6 inches diameter, you will have a wood roughly similar in density to European Elm (Ulmus spp.) and you can make a bow which is a close replica in shape.
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.

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Re: Degame Danish Flat Bow [Holmegaard / Mollegabet]

#20 Post by sylakone » Sat Feb 28, 2015 9:16 am

Thank you

I spose I meant to half the thickness from the dimensions as a starting point before tillering and as you have pointed out reduce the draw weight as I tiller.

I am still quite new to bow making so any tips anyone can give me is always a great help.

Thanks for your sage advice.

Cheers

Sy
Cheers

Sy

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Re: Degame Danish Flat Bow [Holmegaard / Mollegabet]

#21 Post by Dennis La Varenne » Sat Feb 28, 2015 12:47 pm

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.

My own personal advice about taking advice is to look for advice which is evidence-based rather than just on say-so so far as possible. Always ask for reasons and predictable results from application of that advice such as - if you do A, B and C, then E will result if that makes sense.

But as all of us will attest, a broken bow, disheartening as it is, is one of the biggest teachers of them all because we then have to ask Why.
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.

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Re: Degame Danish Flat Bow [Holmegaard / Mollegabet]

#22 Post by greybeard » Sat Feb 28, 2015 4:38 pm

I managed to loose some arrows at the club today and was quite pleased with the way the Degame bow performed.

Arrow velocity was certainly acceptable, unfortunately the centre serving on the string was too thick and the nocks really locked on which would have been detrimental to the bows performance and arrow flight.

Sy,

Dennis has covered the main points so if you get stuck on a particular issue don’t be afraid to ask for help.

As you work through your project some perceived issues may even resolve themselves.

The following is only applicable if you are using a milled board [violated grain on the back] and the bow is going to have a ‘dead flat’ back.

You are at the point when the bow is in tiller but you need to reduce the draw weight; remember that selfbows can shed anywhere between five to ten pounds during the shooting in period.

In most instances material is removed from the belly when reducing the poundage but in the case of the Holmegaard the belly is profiled with thickened tips.

An easy way to shed poundage is to reduce the timber on the back of the bow using a belt sander or sanding stick with a liberal application of elbow grease.

This method may appear unorthodox but it does work and it will reduce mass in the non working section of the limbs at the same time.

Remember to brace and exercise the bow every time you remove timber, this will help to 'set' the changes you have made.

The bow in the following link [if you have not seen it] was made from a sapling with a diameter of a little over two inches and features a crowned back.

http://www.ozbow.net/phpBB3/viewtopic.php?f=34&t=15152

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!....

Dennis La Varenne
Posts: 1776
Joined: Sun Sep 07, 2003 10:56 pm
Location: Tocumwal, NSW. Australia

Re: Degame Danish Flat Bow [Holmegaard / Mollegabet]

#23 Post by Dennis La Varenne » Sun Mar 01, 2015 3:14 pm

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 working diagram using a 20lb bow as the exampled bow.
thickness-draw weight ratio for 20lb bow.jpg
thickness-draw weight ratio for 20lb bow.jpg (62.6 KiB) Viewed 12654 times
So you can see that for every 14% of increased thickness or reduction, your bow's draw weight will either double or halve.

The principle being that you do not have to take much off or leave more on to get a significant change in draw weight. For instance, if your 20lb bow was 1/2 inch (0.500") thick at mid limb, then 14.28% of that is 0.714" which is close to 1.8mm to double this bow's draw weight from 20lbs to 40lbs or bring it back to 10lbs if removed.

There is one more of bowyery's basic rules which has slipped my mind for the present but I can add that later.
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.

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Re: Degame Danish Flat Bow [Holmegaard / Mollegabet]

#24 Post by sylakone » Fri Mar 06, 2015 11:58 am

Hi Guys

Unfortuantley I have not been well for the last 2 weeks so I have not been able to start my molgabet with a piece of spotted gum I have.
Now I am getting close to being well enough to start the cut just a few quick queries.
The piece of Spotted Gum I have is a back sawn piece so the growth rings are horizontal to the width I will put up a pic.
I'm deciding which side to use for the back.
Now my gut says that I should be looking at using the outside of the growth rings as the back since it is usually the way you wood go if it was a natural stave.
The only problem is that the grain is much more violated on that side.
On the inside the grain looks quite good and continuous all the way down the length.
What do you think I should do?
The Growth Rings
The Growth Rings
growthsm.jpg (260.49 KiB) Viewed 12625 times
outside 1
outside 1
outside1sm.jpg (301.63 KiB) Viewed 12625 times
Outside 2
Outside 2
outside2sm.jpg (307.91 KiB) Viewed 12625 times
The other thing is should I back it?
I have some dog bone rawhide I was thinking of using.

I was also hoping to get 2 bows out of the piece of wood.

Cheers

Sy
Cheers

Sy

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greybeard
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Re: Degame Danish Flat Bow [Holmegaard / Mollegabet]

#25 Post by greybeard » Fri Mar 06, 2015 3:25 pm

sylakone wrote:.....I was also hoping to get 2 bows out of the piece of wood......
Sy,

I would be happy to get one good bow out of the board.

The grain orientation looks quite good, looking down the edge of the board does the grain run parallel to the back / belly or does it run off at an angle between these surfaces?

If the grain runs parallel can you follow a growth ring and is the board is thick enough to give you a crowned back on the stave?

This section of board should yield better results.
Section Of S G Board.jpg
Section Of S G Board.jpg (45.93 KiB) Viewed 12617 times
Sometimes I have found that I have to lay the plan of the bow a little on the diagonal to optimize the grain.

If the offcut is wide enough you may get a rectangular cross section longbow out of it.

Have you worked out the handle and fade dimensions yet?

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.
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Re: Degame Danish Flat Bow [Holmegaard / Mollegabet]

#26 Post by Dennis La Varenne » Fri Mar 06, 2015 5:10 pm

Sy,

Darryl is right about the grain orientation, and it will be a good bit of work to get the back crowned as he suggests.

My limited use of Australian hardwoods leads me to consider that because they are perennials, they do not have the same degree of problems with splitting between the growth rings as seems to be a problem with the northern hemisphere deciduous species.

These deciduous species have a dormant period followed by a rapid period of spring growth of very porous wood which is quite soft. This soft stuff is usually termed 'early wood' and the later summer growth which is much denser is called 'late wood'. The greater the proportion of late wood, the stronger and denser the wood.

Deciduous species tend to split along the early wood and out through the late wood when they go.

Our species are similar to the tropical hardwoods which have annual rings which vary more on seasonal variation, nutrient and water availability, but with no real cessation of growth, so ours tend not let go from the same reasons because there is a much greater proportion of denser wood.

This is all a long-winded way of saying that so long as your bow is not too high a draw weight and is kept reasonably long, you will probably not need to back it
Dennis La Varénne

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Re: Degame Danish Flat Bow [Holmegaard / Mollegabet]

#27 Post by sylakone » Fri Mar 06, 2015 7:32 pm

greybeard wrote:
sylakone wrote:.....I was also hoping to get 2 bows out of the piece of wood......
Sy,

I would be happy to get one good bow out of the board.

The grain orientation looks quite good, looking down the edge of the board does the grain run parallel to the back / belly or does it run off at an angle between these surfaces?

If the grain runs parallel can you follow a growth ring and is the board is thick enough to give you a crowned back on the stave?

This section of board should yield better results.
The attachment Section Of S G Board.jpg is no longer available
Sometimes I have found that I have to lay the plan of the bow a little on the diagonal to optimize the grain.

If the offcut is wide enough you may get a rectangular cross section longbow out of it.

Have you worked out the handle and fade dimensions yet?

Daryl.
Hi Daryl

At one end I have shown you the growth rings. At about 300mm from the end there is run-off where there is a knot after that it is straight all the way to the other end.

The board is about 2200mm long and 80mm wide and 19mm thick.
So I can safely cut off the board before the knot and still have plenty of length for the bow.
I am not sure if I can get a crowned back all the way as if you see in the pics there are points where the growth ring has been violated.
It might be possible.
Attachments
knot.jpg
knot.jpg (240.63 KiB) Viewed 12609 times
Cheers

Sy

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