Decided to try a longer Asiatic bow -- Not sure how to describe its length but the laminations are six foot long, I would have made it longer but that is the full length of the bamboo flooring so I went with that. Also I thought I would try heaps of recurve and reflex, will be interesting to see if I can get it stable enough to draw.
Graeme
Long Horse Bow
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Long Horse Bow
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longbow steve
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Hi Steve
Probably Bowtuff on the back and rovings on the belly so I have enough material to tiller -- given I have no idea how it will bend this will give me more chance to get it to shoot and allow me to refine the core dimensions. This is assuming that I can keep a string on it.
What would life be without a challenge
Graeme
P.S Who do you buy your flooring off and how long is it.
Probably Bowtuff on the back and rovings on the belly so I have enough material to tiller -- given I have no idea how it will bend this will give me more chance to get it to shoot and allow me to refine the core dimensions. This is assuming that I can keep a string on it.
What would life be without a challenge
Graeme
P.S Who do you buy your flooring off and how long is it.
Graeme,
Well done so far. This one looks like it could be real stunner! The radical siyahs or recurves (?) will make stringing this bow very interesting. You may need to consider using a pair of tepliks to pre-load each limb, just to get the string on. This picture and link below are from a slide show which shows the process of stringing a fully curved horn bow - pity we can't read Hungarian. I will be following your thread with real interest - good luck. http://www.my-bow.hu/?q=node/184
Well done so far. This one looks like it could be real stunner! The radical siyahs or recurves (?) will make stringing this bow very interesting. You may need to consider using a pair of tepliks to pre-load each limb, just to get the string on. This picture and link below are from a slide show which shows the process of stringing a fully curved horn bow - pity we can't read Hungarian. I will be following your thread with real interest - good luck. http://www.my-bow.hu/?q=node/184
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"The greater danger for most of us lies not in setting our aim too high and falling short; but in setting our aim too low, and achieving our mark." (Michelangelo Buonarroti)
Hi Archangel
I agree -- stringing it will be difficult and I will probably make a jig of some sort to make it easier but I think keeping a string on it may prove to be more difficult than getting it on in the first place. There is a conflict between making these types of bows lowish draw weights and having stiff enough limbs to avoid them rolling over and shedding the string. I think this problem is the reason you do not see many bows with radical recurve and reflex despite the fact that it well known that this achieves high arrow speed.
Graeme
I agree -- stringing it will be difficult and I will probably make a jig of some sort to make it easier but I think keeping a string on it may prove to be more difficult than getting it on in the first place. There is a conflict between making these types of bows lowish draw weights and having stiff enough limbs to avoid them rolling over and shedding the string. I think this problem is the reason you do not see many bows with radical recurve and reflex despite the fact that it well known that this achieves high arrow speed.
Graeme
Graeme wrote:
Makes sense Graeme. This is the problem I have with the hornbow I have just finished glueing up. The siyah tips are so forward of the reflex handle that it feels like it may twist off the string. I am contemplating cutting off the siyahs and resplicing them to achieve a drastically reduced angle to the limb. Just as an aside, notice the guy in the photo who is tying the bow to the limb teplik is standing with his face "out of the firing line" ... this is not the sort of picture or demo you would want beginners to watch. I shudder to think what would happen if his burly mate let go that limb by mistake!!There is a conflict between making these types of bows lowish draw weights and having stiff enough limbs to avoid them rolling over and shedding the string.
"The greater danger for most of us lies not in setting our aim too high and falling short; but in setting our aim too low, and achieving our mark." (Michelangelo Buonarroti)
Hi Archangel
I have found that if the limbs do not have enough torsional strength to resist the string wanting to twist off at brace height then reducing the angle the siyahs will not fix it unless it means that at brace height the string is just lifting off so it has no pressure on the siyahs.
Sometimes if the problem is not bad you can fix it by shortening the siyahs as this reduces the moment caused by the out of line but this is only a minor adjustment.
I have found that the only real fix is to increase the brace height and / or change the siyahs in such a way as to lift the string off at brace height --- this always fixes the problem but it destroys the design advantage of the siyahs by taking away the effect of the bow working like a short bow to start with then like a longer bow at full draw.
Graeme
I have found that if the limbs do not have enough torsional strength to resist the string wanting to twist off at brace height then reducing the angle the siyahs will not fix it unless it means that at brace height the string is just lifting off so it has no pressure on the siyahs.
Sometimes if the problem is not bad you can fix it by shortening the siyahs as this reduces the moment caused by the out of line but this is only a minor adjustment.
I have found that the only real fix is to increase the brace height and / or change the siyahs in such a way as to lift the string off at brace height --- this always fixes the problem but it destroys the design advantage of the siyahs by taking away the effect of the bow working like a short bow to start with then like a longer bow at full draw.
Graeme
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longbow steve
- Posts: 3116
- Joined: Tue Jan 30, 2007 3:29 pm
- Location: BLUE MOUNTAINS
Hi Steve
I have been a bit slack the last couple of weeks.
Had a few other things to get done -- including making the trophies for the Bare Bow Challenge and fitting a new TV in my camper amongst other things.
Also I had to wait for some glass to come from the US --- I thing that is about all the excuses I can think of for now.
So I glued the Bowtuff to the back and tidied it up. I then tried to get it up on my tiller board but it was way too heavy and not torsionally stiff enough to string ( as I had expected ) so I grabbed it in the vice with a couple of shaped blocks and tried bending just one arm which I managed to do with a little difficulty and some help to hold it from twisting -- found that it took about 75 pound to get it back to brace height.
Decided the only plan was to cut off the tips to avoiding the twisting and narrow the limbs which I did from the handle down to a half inch at the tips. This worked quite well and it is now about 60 pound at brace height with a long string so I am going to do the nocks and try it with a short string but I think it will still be too heavy. I do like the design so if it is too heavy I guess I will remove the belly glass and thin down the core to get the weight.
Graeme
I have been a bit slack the last couple of weeks.
Had a few other things to get done -- including making the trophies for the Bare Bow Challenge and fitting a new TV in my camper amongst other things.
Also I had to wait for some glass to come from the US --- I thing that is about all the excuses I can think of for now.
So I glued the Bowtuff to the back and tidied it up. I then tried to get it up on my tiller board but it was way too heavy and not torsionally stiff enough to string ( as I had expected ) so I grabbed it in the vice with a couple of shaped blocks and tried bending just one arm which I managed to do with a little difficulty and some help to hold it from twisting -- found that it took about 75 pound to get it back to brace height.
Decided the only plan was to cut off the tips to avoiding the twisting and narrow the limbs which I did from the handle down to a half inch at the tips. This worked quite well and it is now about 60 pound at brace height with a long string so I am going to do the nocks and try it with a short string but I think it will still be too heavy. I do like the design so if it is too heavy I guess I will remove the belly glass and thin down the core to get the weight.
Graeme
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G'day GraemeGraeme K wrote:...Pity you are so far away -- I figure it would make my horse bow project a heap easier if I was able to see some of these bows in real life rather than just photos. ...
You never know, one day we might catch up on the shooting range.
The bow is looking very good so far.
Happy shooting
They'll never hit us from this dist....
Hi All
Last installment.
Measured the full draw weight with the rovings on the belly ( 75#) and did the calc on how much I needed to reduce the thickness to get the weight down to the 40 to 50# range. Removed the belly glass and thinned down the core accurately ( rotten job ) before I glued on a replacement of 40 thou Bowtuff.
Below are the photos of the results --( Ignore the odd uneven shape, I have made no attempt to balance the arms since I replaced the glass.)
I t would seem that I have proved that the bow tuff makes the bow about twice as heavy as the rovings which is a lot more than I would have expected -- my guess was about 20% still you live and learn.
The result is that the bow is still 80# at 28" --- too much bow for me, guess I am just a girl.
The interesting thing is that the bow is 50# at 20" which equates to 4.5 pound per inch of draw starting from a 7" brace height and 80# at 28" draw which is 3.75 pound per inch of draw. So although from the photos it looks like the thing would be stacking like crazy towards the end of the draw in fact the early draw weight is so high that it makes the end of the draw look OK by comparison although I am sure it must be stacking.
I think this must be the perfect example of high early draw weight caused by a massive amount of reflex.
I reckon that this is the end of this one since the I dont have the energy to take it apart again and I figure I have learnt all I can from it.
Graeme
Last installment.
Measured the full draw weight with the rovings on the belly ( 75#) and did the calc on how much I needed to reduce the thickness to get the weight down to the 40 to 50# range. Removed the belly glass and thinned down the core accurately ( rotten job ) before I glued on a replacement of 40 thou Bowtuff.
Below are the photos of the results --( Ignore the odd uneven shape, I have made no attempt to balance the arms since I replaced the glass.)
I t would seem that I have proved that the bow tuff makes the bow about twice as heavy as the rovings which is a lot more than I would have expected -- my guess was about 20% still you live and learn.
The result is that the bow is still 80# at 28" --- too much bow for me, guess I am just a girl.
The interesting thing is that the bow is 50# at 20" which equates to 4.5 pound per inch of draw starting from a 7" brace height and 80# at 28" draw which is 3.75 pound per inch of draw. So although from the photos it looks like the thing would be stacking like crazy towards the end of the draw in fact the early draw weight is so high that it makes the end of the draw look OK by comparison although I am sure it must be stacking.
I think this must be the perfect example of high early draw weight caused by a massive amount of reflex.
I reckon that this is the end of this one since the I dont have the energy to take it apart again and I figure I have learnt all I can from it.
Graeme
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Wow, 80# at 28" I'm impressed that you had the courage to draw it back that far Graeme! It would certainly make an amazing foot bow useful if you wanted to break a flight record.
Thanks for sharing the experience, you have surely taken this build as far as you can.I reckon that this is the end of this one since the I dont have the energy to take it apart again and I figure I have learnt all I can from it.
"The greater danger for most of us lies not in setting our aim too high and falling short; but in setting our aim too low, and achieving our mark." (Michelangelo Buonarroti)
Hi Archangel
It was a bit scary drawing it but experience has taught me to be cautious and keep my head well away from the tillering board as I draw it down --- had a couple of nasty glancing blows from broken bows on the board.
The really scary thing is trying to string It -- there is so much recurve that it takes a lot more than 50# to get it to brace and the only way I can do it is grab the handle in shaped blocks in the vice and pull one arm forward and prop it there with a stick then pull the other arm around. You keep wondering if it is going to slip out of the vice and try to kill you, and you just know it will be bad because it takes all your strength to pull just one arm around.
Graeme
It was a bit scary drawing it but experience has taught me to be cautious and keep my head well away from the tillering board as I draw it down --- had a couple of nasty glancing blows from broken bows on the board.
The really scary thing is trying to string It -- there is so much recurve that it takes a lot more than 50# to get it to brace and the only way I can do it is grab the handle in shaped blocks in the vice and pull one arm forward and prop it there with a stick then pull the other arm around. You keep wondering if it is going to slip out of the vice and try to kill you, and you just know it will be bad because it takes all your strength to pull just one arm around.
Graeme
Hi Graeme,
Thank you for the thread.
You have certainly pushed to the limits the materials used in this project and the beast held together. The information you have gathered will certainly be beneficial in your next projects be they static tip, recurve or longbow.
When you get the bow back to full draw can you let us know if there is much hand shock
only joking,
Daryl
Thank you for the thread.
You have certainly pushed to the limits the materials used in this project and the beast held together. The information you have gathered will certainly be beneficial in your next projects be they static tip, recurve or longbow.
When you get the bow back to full draw can you let us know if there is much hand shock
only joking,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 Daryl
Although I can not fully draw it I have given it my best try and managed about 25" which is about 70# and surprisingly it has no noticeable hand shock but if you saw how tiny and skinny the limbs are I doubt that you would be all that amazed. The whole bow only weighs 460g ( 17oz) and I reckon two thirds of that is handle and non working limb.
Graeme
Although I can not fully draw it I have given it my best try and managed about 25" which is about 70# and surprisingly it has no noticeable hand shock but if you saw how tiny and skinny the limbs are I doubt that you would be all that amazed. The whole bow only weighs 460g ( 17oz) and I reckon two thirds of that is handle and non working limb.
Graeme
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longbow steve
- Posts: 3116
- Joined: Tue Jan 30, 2007 3:29 pm
- Location: BLUE MOUNTAINS