[English Longbow] Cast on Longbow

dusty

New member
Having made a couple of laminated long bows. I was thinking how to improve cast.
Selection of timber is important but was thinking if I was to taper the laminates would this help as It does on flat bows.
When glueing up the bow up how much reflex could you glue in to help stop string follow
Does anyone have experience with this and how it works
 
D

Deleted member 7654

Guest
Hmm tricky Q to answer briefly, but a laminated longbow from your descriptions sounds a slight contradiction in terms. Generally a laminated longbow would be one main piece of timber (possibly jointed in the middle if necessity dictated) backed with say Hickory or Bamboo, and it wouldn't have recurve.
Native American flat bows (and many others) often had a bit of recurve, but these were short bows and the recurve was to help the string angle at full draw (avoids the string pulling off!)
Your description sound more like a recuve with a tapered core and glass fibre lams on back and belly.
Anyhow, generally it's the stave which dictates the bow design.

Flatter limb profiles give less stress on the timber and thus generally less string follow, thus my current work in progress in Beech is a flat bow as Beech isn't a 'good' bow wood, the flat profile will maximise the cast from a relatively poor wood.
Regarding recurve...there are working and non-working recuves. If your design will take a recurve it probably wasn't going to follow the sting.
EG, I made a little Ash flat bow and it followed the string a bit. I steamed in some recurve (just for the fun of trying steaming) It retained some recurve but the overall string follow was about the same....It did look prettier tho' :).
The quality and type of timber dictates whether it will take the classic longbow profile without string follow or compression cracks in the belly.
That's about it for a brief explanation.
I've not built a backed longbow as such, but there is plenty of info out there.
(Terms and conditions apply, I reserve the right to be wrong :) )
Give us more info and there will doubtless be more helpful responses.
Del (Sorry if I've got the wrong end of the stick somewhere)
 

Huffy

New member
I did a longbow making course run by Chris Boyton a number of years back I sure that the laminated stave he provided had been glued up so that the ends had been raised by a couple of inches. I believe the idea was to compensate for the initial set when making the bow.

Best wishes, Mark
 

cloutman360

New member
I normally reflex the bowstave by a couple of inches to allow for string follow later on.
Once the rubber bindings are on, with the glue still wet,you can move it and it will hold it's new shape.
 
D

Deleted member 7654

Guest
Like the other guys say, a little 'back set' is sometimes built in, but I wouldn't class this as recurve.
If I ignore the 'longbow' requirement, then here's my best thoughts on cast. (ignoring stuff like lighter arrows)
1) More cast fundamentally requires more power.
2) More power requires either:-
a) More draw weight, either as final poundage at full draw, or poundage earlier on in the draw like the Asiatic styles of bow (e.g Recurve). You could say the ideal 40lb bow would draw 40lb all the way up I s'pose :scratchch.
b) Longer draw length.

The problem with just adding recurve, or even simply increasing the draw length, is the materials may not be up to it and string follow will be the result.
Hope this is some help.
Del
 

ChakaZulu

New member
He said reflex, Del, not recurve. Means the same as backset, basically.

I agree with Del basically on requirements, but with a little variation. Cast is to do with the amount of stored energy passed to the arrow. This obviously requires more stored energy and less resistance to its transference.

Resistance to transfer of energy largely consists of arrow and string weight, plus bracing height and tuning etc. Nice light limb tips will also help as they move faster.

Getting more energy is as Del says - increase early draw weight, increase total draw weight, increase draw length.

One thing you could try is the Perry reflex. I've not tried it myself but I'm told it's very effective if done right. Basically you flex each laminate before gluing them in their reflexed positions. There's more to it than that, but that's the basics. Google it or get TBB if you're interested.
 

ChakaZulu

New member
By the way, there's now a shiny new forum for bow building and relating topics, to be found in the Pavilion :beer:
 

Huffy

New member
Another way of improving cast would be to reduce the mass weight at the tips of the bow. The horn nocks should be cut down to the minimum and the timber at the ends should also be at a minimum. I believe the Mary Rose bows tapered down to a surprisingly small diameter at the tips and this is an area where beginners often leave excess timber on their bows.

Best wishes, Mark
 

ChakaZulu

New member
Absolutely. With one caveat. You don't want the limb tips to bend too much, as that will cause stack and therefore reduce stored energy at a given draw weight.

This shouldn't be too muc of a problem with an ELB because of it cross-section. With a flatbow it's important to reduce mass from the width more than from the thickness.
 

Huffy

New member
Absolutely. With one caveat. You don't want the limb tips to bend too much, as that will cause stack and therefore reduce stored energy at a given draw weight.

This shouldn't be too muc of a problem with an ELB because of it cross-section. With a flatbow it's important to reduce mass from the width more than from the thickness.

Very true but I have seen horn nocks on the ends of long bows that would be more at home on a Chess board and they have to be robbing speed from the bow.:raspberry

Best wishes, Mark
 
D

Deleted member 7654

Guest
Dratt, now I look like an ar$e... there must be an 'embarrassed' smilie somewhere. :)
Still the 'tapered lams' thing sent my brain in the wrong direction.

Del
 

dusty

New member
Longbows

Thanks for the reply
The reason that I ask the question was I pay a visit to KG archery the other day and they now taper the laminates on there longbows to improve the speed of the tips of there bows so improving cast because they say it works well on the recurve limbs.
Has anybody shot one of these bows
I did mean relfex / back set.
I have also seen a video of Chris Boyton Steaming a yew stave to put a small recurve tip on the end. This would be possible I think with a laminated long bow if you steamed the pieces before you glued them up as I would have thought the steaming would affect the glue line
Questions
If you where to recurve the tips of a long bow
Would it be legal to shot
Would it improve the performance enough to warrent the extra work involved
Has anyone done this or shot a longbow with recurve tips
 

dusty

New member
longbow nocks

Another way of improving cast would be to reduce the mass weight at the tips of the bow. The horn nocks should be cut down to the minimum and the timber at the ends should also be at a minimum. I believe the Mary Rose bows tapered down to a surprisingly small diameter at the tips and this is an area where beginners often leave excess timber on their bows.

Best wishes, Mark
I had the same thought about horn nocks
So would it pay to leave the bow self nocked
 
D

Deleted member 7654

Guest
This is just my opinion I'm sure some will dissagree. :scratchch
There is no point recurving the tips of a longbow.
To get the maximum cast from a stave you want to get 100% of the available power from it.
Q. How can you tell you are doing this?
A. Assuming a reasonable 'design', you will start to get a little string follow! Because if there is NO string follow the implication is you could be getting more out of the stave. E.G. If the draw weight/length is exactly how you want them, it implies the bow could be slightly shorter, and thus lighter with the limbs curving more.
If you are at this point where string follow is just starting, then adding any recurve will just increase the follow.
I see a lot of longbows that just aren't doing much work..say 35lb longbow which is 73" long and barely flexes at 28" draw. (In a heavy/war bow a shallow arc like that is ok because the stave is so much thicker and more highly stressed).
(I'm perfectly happy to be shot down on this)
Del
PS Tapered laminations implies the bow is made up of at least 3 laminations, in which case a tapered core does make some sense, but isn't this getting rather away from a longbow which is at least making a pretence of being a 'self' bow (or am I just getting pompous now? :eek:)
 

Huffy

New member
I had the same thought about horn nocks
So would it pay to leave the bow self nocked
I suppose it would if efficiency was the main requirement but horn nocks do protect the bow in the string grooves and are required for GNAS and BLBS rules.

I think the idea is to keep them small and neat.

Best wishes, Mark
 

ChakaZulu

New member
I'm not sure they are still required, are they? I thought Alanesq had got it changed in his search for a vegan bow.

They do protect the wood, but a hardwood inlay could do that.

More to the point, even if you do need horn nocks, it seems to me that big, elaborately carved nocks must reduce the limb tip speed more than a simple horn overlay that just cover the tip.

Raises the question of what a bow is actually for. Hmm. New thread for the DIY section!


EDIT: just seen that you did address the point about small and neat!
 

English Bowman

Well-known member
The rules still state horn nocks, although I believe that Alan got a judge to say that imitation horn would be acceptable. I don't know how they'd tell the difference to be honest.

Daniel
 
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