Fishing The Fly Scotland
Index => Rod Building => Topic started by: Bronzebommer on 04/03/2010 at 10:23
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On the 2 rods I have built I have made sure the rings are mounted to the inside curve of the blank spine. How much difference does this make? I was talking to Mr B about this and he says "allot". If so, how come Hardy’s didn’t bother when making my Demon? ??? Is the spine something that is only given consideration in more expensive models? or does it vary between manufactures? Your thoughts please. :z3
Matt
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Now you're asking a question you will get different opinions on
I have done lots of playing with this
so my opinion is it does make quite a lot of difference in the rod when it comes to control.
If the spine is straight then the rod will cast itself straight
on powerful casting machines and when you start to haul for distance
the subtle accuracy the spine gives you is over ruled and it makes no difference.
However should you try delicate stuff with a rod without a straight spine it will cast offline.
Casting of axis should be something you Introduce ,not the rod IMHO.
Production rods are not spined because it takes to long and a spined rod is often not
straight so they just wrap for straight because in the shop people pick up a rod and look along it,
bent rods don't sell as well. If you were to buy based on casting then a spined rod would feel more natural in the hand
and you would prefer it, but unfortunatley most rods aren't sold this way.
Most custom builders agree on spining and have experimented with it at length.
I can tell you that if you build on a stiff blank (fast action+) then putting the rings
on the outside of the spine makes the rod even better. Doesn't seem to work the same with
a more gentle action.
My theory on this is you use a faster rod for casting greater distance, if the rings are on the outside of the spine
then on the forward cast the more powerful part of the blank tracks truer and it keeps your tracking straighter when you come forward without you trying as hard, therefore you cast further and straighter with less effort.
With the rings inside the spine you load the spine on the backcast which throws the line out straighter behind you and makes it easier to shape the line better coming forward as it is already tracking straight, this lends itself to more medium actions where you will cast shorter distances and be looking for accuracy and shapes in the line.
I'm not explaining this very well , sorry :oops Its very hard to explain, but quite easy to demonstrate
Mike and I have proven this many time. With different builds on blanks
and having people blind test the same blank in 4 different configs
without exception they will always choose the spined blank as the better rod
even though they are the same .
I have rebuilt quite a few factory rods and spined them on rebuild
to have the owner think you have performed some sort of magic trick with their rod
it feels quite good to improve something people used to love. :z3
also you will find on a 4 piece rod you only need to spine the top 2 sections :wink
So spine a medium-fast action on the inside of the spine and a fast to extra fast rod on the outside of the spine.
as I said it is an opinion, but from my experience it is a very well proven opinion.
Cheers
Sandy :z18
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Ah, to spline or not to spline.
It's very true that an unsplined rod is softer than a splined rod. However, a splined rod is much more liable to twisting forces on a cast. This is the bit that worries me the most and perhaps most misunderstood.
When finding the spline, the blank will snap into a natural curve, a curve the is approximatly 90 degrees to the spline. If you place you rings on or opposite the spline, on a cast the rod will want to twist into it's natural curve, which is 90 degrees to where the rings are. So, I cannot fully agree with sandy on the bit regarding better acuracy when splined because the rod is constantly trying to twist into it's natural curve.
Dealing as I do in heavy fly rods this can manifest itself into tips flying off during the cast as The twisting forces can be large. I now build my rods off spline, as recomended by the manufacturer. Having said that, with autoclave technology, the spline is almost non existent on certain manufacturers rods.
As I build a lot of "sets of rods" I will often have 2 or 3 identical blanks and have played around with splines, ringss and spacing and as sandy says, it makes a remarkable difference, even on heavy carp rods. But I think the jury is still out on whether splining or not is better. There is certainly no right or wrong answer and many manufacturers build the rod by seeing how straight it looks rather than to a spline.
For me, I like to think the rod is working on it's natural curve rather than against it so will build it how I think it flexes best, but also recognise others want it splined, so will normally ask the client....then I am in the clear lol
I wish forums were touchy feely as it is so much easier to demonstrate than describe.
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Interesting stuff Rob.
If the spine/spline is at 90' to the preferred plane of bending (most peoples impression of what the spine is)
How do you establish where it is?.
I always use the preferred plane of bending and perhaps wrongly refer to it as the spine, people seem to understand better what that means when you call it a specific name and they can also find it much easier.
To me, when people refer to a spine/spline they are reffering to what i personally call the prefferred plane of bending, this is a mouthful for describing things and perhaps even sounds a little contrived to the layman. With cane they are very much the same thing, so it was natural to assume the same for carbon.
However perhaps you are correct, from now on i shall not use the term spine or spline if that is not what the PPB represents.
From what you say we are talking the same game, but referring to it with different terminology. :z6
:z18
Sandy
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Rob,
You are at it again . :z4
Dealing as I do in heavy fly rods this can manifest itself into tips flying off during the cast as The twisting forces can be large.
Aye they must be .
:roll
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Sandy,
and this is the problem! It depends who you speak too! I think most people refer to the spline or spine as being the plane in which the rod gives the most resistence when you bend it. As you are more than aware, when you take say the tip and bend/roll it you feel 4 destinct phases as you turn it. The stiffest phase is often referred to as the spine/spline. As you will know, the blank will try and "snap" to a preferred plane. This is the plane I tend to build along, which tends to be roughly 90 degrees to the stiffest part.
I got a new catalogue through this morning from a UK company called Free Spirit who produce some fantastic Japanese cloth carp rods, here is an extract from it....
"We take great pains to ensure out rods are whipped along the spine(backbone) of the rod. This is important since the rod aligns naturally to this spine during casting and fish playing - if you feel the rod snatching during the cast or have a top section that twists around on the cast this is probably down to it being built off spine.
On the long range rods this is vital since if built off spine the carbon fibres will try to align themselves to the spine during heavy casting and can "unwrap" leading to rod breakage....."
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Sorry, on the I phone and it would not let me add more.....
So, there you have it, both Harrison and Free Spirit mention the spline and how important it is to align, but neither actually tells you what the spine is, the natural curve or the stiffest resistence!
The fact a Human spine flexes front to back better than the stiffer side to side suggests the natural curve of a blank is the spine. I don't know, but that's how I build my rods.
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The fact a Human spine flexes front to back better than the stiffer side to side suggests the natural curve of a blank is the spine. I don't know, but that's how I build my rods.
Me too :z16
The analagy with the human spine is probably one of the most enlightened coments i've seen you write :z18
Sums up exactly how most people view the situation. And as you say, if it bends in this direction the stiffer parts are most probably at 90' to the PPB.
All good stuff :z12
Sandy
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Me too :z16
The analagy with the human spine is probably one of the most enlightened coments i've seen you write :z18
Sums up exactly how most people view the situation. And as you say, if it bends in this direction the stiffer parts are most probably at 90' to the PPB.
All good stuff :z12
Sandy
Hi Sandy,
Preferred plane of bending is correct in my opinion. The casting and tracking performance during the cast is dramatically improved.
90 degrees to the major and minor spines (there are two stiff spines, or areas, on every blank) is where I always advise the guides be fitted.
Regards,
David.
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David,
thank you for your input, it is good to get confirmation from someone like yourself.
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Will echo that, cheers David :z1
terminology has a lot to answer for :z6
Sandy
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It's confusing isn't it?
I was brought up to believe that to have spine was to be brave, have resolve, backbone etc. Spine...... That always meant stiff. As in stiff upper lip. Yet physically our bodies spine is designed to be stiffer in three planes, and more flexible in one. That makes it even more confusing then when using the human body's spine as an example!
I have always then looked at rod spine, as being the stiff side of the blank.
The blank when flexed won't stay on that stiff plane though, it automatically wants to turn to the preferred plane of bending. The softest side. It follows then in my mind - looking at it logically, that this is were the guides should be located - so the cast and the way the rod bends during the cast takes advantage of the natural bend in the rod shaft.
In a multi-section rod, any rod... if they are all lined up, it follows then that the complete rod when flexed is not fighting for position with the adjoining section. It tracks truer throughout the forward and back cast automatically, which must make for a smoother cast. A proficient caster would certainly notice the difference if offered a "tuned" rod in comparison with a rod that had just been randomly assembled. An average or below average caster, may never notice any difference.
I think though that it must be reassuring - even if the end user is an average caster - that the rod he is building or buying, will have that built in tweak that overall - will enhance the final casting performance.
Regards,
David.
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Very nicely put, far neater than my waffle at the start :z6
the next question is though, which side of the preffered plane of bending
would you use, we have found that it can have an affect on the rod too
and can be used to further tune a blank depending on it's nature.
With a softer action rod It has it's sensitivity increased by putting the rings on the inside of the curve
wheras we have also found that with a stiffer faster blank you can Improve it's tracking by putting the rings on the outside of the curve. Again you only really notice when you do direct comparisons during experimental stages
but. The knowledge that people benefit from these small observations
has always appealed to me, guess that's why I love building rods :z16
sandy
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Very nicely put, far neater than my waffle at the start :z6
the next question is though, which side of the preffered plane of bending
would you use, we have found that it can have an affect on the rod too
and can be used to further tune a blank depending on it's nature.
With a softer action rod It has it's sensitivity increased by putting the rings on the inside of the curve
wheras we have also found that with a stiffer faster blank you can Improve it's tracking by putting the rings on the outside of the curve. Again you only really notice when you do direct comparisons during experimental stages
but. The knowledge that people benefit from these small observations
has always appealed to me, guess that's why I love building rods :z16
sandy
Hi Sandy,
Irrespective of thie action, I always prefer to have it rung on the major side of the preferred plane of bending. That way you get mamum power into the back cast as you lift line from the water. This translates into higher line speed. The rod will then load automatically slightly deeper on the forward cast.
As we have located the planes of bending throughout the rod shats, the cast - assuming it has been made efficiently and with appropriate energy input for the presentation required - allows the rod to track true and unload the stored energy smoothly, projecting the line forward without any bumps, waves or wobbles.
get to.
I think rod making can get to be more than just a love for the craft. It can turn into an all consuming passion if you are not careful...... :grin
Regards,
David.
ps Mike if you are reading this, I constantly have an issue with the reply box annoyingly disappearing below the line I am typing. I'm using Vista home premium. I have had to resort to using Microsoft Word to make my reply. Then copy and paste it in to the reply box.
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I think rod making can get to be more than just a love for the craft. It can turn into an all consuming passion if you are not careful...... :grin
Too late for that :shock passed that a long time ago, remember i'm sitting here in the jungle having the discussion :z6
Haven't built a rod for 11 months now :cry however i have been making handles and coming up with ideas to try after the summer (when i'm bringing my gear back here with me :z3) All way too sad :roll
What i've found with rings and the PPB, is as you say, when you put them on the outside of the curve it improves the line speed and accuracy of the rod, without input from the caster, with the input, it maximises what you can achieve. Most of this comes from the improved backcast. However what i have also found is if you put the rings on the inside, then on the fwd cast, the rod will do the same and this allows you better control for off axis casting manouveres, such as bending and shaping the line, i tend to do this short range which is why i think it suits a softer action blank.
It is all of course just opinion and my interpretation of many experimental results, but it does make for some very interesting conversations.
All good fun :z18
Cheers
Sandy
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All exceptionally interesting. Here is one for you then, many years ago I used to build rods for Somers Tackle when they were still located in Thistle street and Jim was still alive.
The blanks were all Hardy Fibatube and two piece.
I found that by placing the rings on the butt section on one side of the preferred plane and the tip rings on the other you could "tune" the rods for different casting styles.
When it came to the 15 foot salmon rods I would ask the customer what kind of casting they did...and whip the rings on the accordingly, on the slightly stiffer side for overhaed casting and softer side for roll/spey. Taking two rods to the river whipped this way you could tell which rod was which by the difference in action.
David,
a question for you, what difference does Autoclaving make to the spine/spline. I ask because I have two Century blanks at home just now (Barbel) and I am struggling to find a spine on them!!!
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Hi Rob,
Autoclaving - this assumes it is done on a rod blank by any rod company- which I have to be honest and say I very much doubt, would make no difference to the way the carbon fibre pattern is rolled on to the blank.
It has to begin and end somewhere. Vacuum bagging which autoclaving is just a variation of, just replaces any other techniques used for compressing the prepreg carbon fibre in the curing oven, autoclaving, will not change that. Autoclaving is more usually used for making odd shaped parts such as bits for F1 cars, wings and the like, not thin tubes.....
If your rod has faint spirals in the finish that have been ground or sanded smooth. It is definitely not autoclaved. If it is coated with an opaque finish so you can't see the spirals. That prevents you checking that out I'm afraid.
All blanks have some sort of spine. The way they are made, a bit like rolling a cigarette, means there has to be. The pattern is put on the mandrel and rolled under pressure. The pattern must end somewhere, and it leaves a thicker overlap in the wall of the blank.
Or if you want to look at it another way, a slightly thinner area around the rest of the blank.
Using very thin pre-prepreg, which equates to more wraps to get a given wall thickness (a technique I use) can reduce, but never eliminate the effect of the overlap.
Are you trying to locate the spine or preferred plane of bending with the guides fitted?
Regards,
David.
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David and Rob,
cracking couple of posts there very informative. I however have a question.
David you mention that the spline/PPB comes from a thicker and thinner part in the plank effectively where the first wrap starts from. I take it this assumes that the first wrap started in a straight line which runs in the same place reference to the centre of the blank all the way to the tip. If this firts wrap was diagonal rather than straight could you effectively eliminate the spline?
Cheers
Matt
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Hi MDH,
The material has to be unidirectional or unidirectional carbon fibre prepreg is not doing its job properly.
Reinforcing can be put on in a diagonal pattern as a weave or bi directional, either within the matrix or on the surface.
The main material that gives the rod shaft stiffness on ALL blanks, despite what you may see on the surface as a weave or pattern, must be laid up unidirectionally from butt to tip or the rod shaft material will not operate in compression or tension properly when flexed.
The carbon (or glass) pattern has to start and end at some point. It can't be moulded on. Carbon comes in sheets that the patterns are cut from then placed on the mandrel.
http://www.youtube.com/watch?v=8qjrvoXJJkQ
Have a look at my YouTube video at the carbon material being cut and you will see how it is prepared. Some of that footage shows the butt section of Mike Barrios Outcast 9ft 5 weight rod blank being made.
Here is a picture of me holding up some carbon pr-preg patterns that will shortly be turned into a 5 section 13.5ft Norwich EV4 Salmon fly rod.
http://www.davidnorwich.com/images/PatternscutOpt.jpg
David.
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Hi David,
Thanks for your reply.
The blank has a woven finish to it, and on close inspection, I cant see a join at all. I believe the blank is a two stage construction, with a central core of "normal" carbon and then an outer wrap of woven carbon/kevlar bonded to it to increase hoop strength when casting big leads. The pattern is not just cosmetic, you can see the weave on the last 6 inches of the butt as it is unfinished.
I wonder if the two "layers" are rolled so that the spines contradict each other in position and thus producing a blank that does not seem to have a preferred bend?
The blank is then autoclaved to compress the two materials together and to force out any bubbles from the weave, thus producing a stronger rod...well, thats what the advertising blurb says. :)
I wonder if the spine is harder to find purely becuse of the poer and thickness of the wall? I seem to recall the old fibreglass carp rods I used to build had less well defined spines than the carbon ones that replaced them...wall thickness?
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Hi Rob,
I've made my comment already on what I know an autoclave is used to manufacture.
If you are in any doubt, you can read for yourself http://en.wikipedia.org/wiki/Autoclave_(industrial) just what an autoclave is and what it is used to make. It isn't used to make fishing rod blanks.
You have to accept "Hype" is a major part of selling any product. Do you honestly believe that the worlds rod manufacturers who tape wrap their blanks then cure them, have air bubbles trapped in them due to an inferior manufacturing process? Sage, Loomis, Shimano, Harrison, Hardy, Winston, Thomas & Thomas. David Norwich etc. We all have it wrong? ???
It may be possible, but I honestly doubt any spine bias is corrected by an overlay of woven carbon fibre in any blank type made by any manufacturer. If it could be done, it could not be done on a fly blanks without a serious weight penalty, as overall the blank would just be far too heavy carrying around a woven overcoat. The reulting performance would be poor because of that alone.
Your glass blank spines where likely more difficult to find because the material is totally woven. Glass is also of a very low modulus of elasticity. Glass fibre rod construction doesn't use unidirectional fibres in the same way as carbon fibre blank construction.
Catch you later. Got to get back to work... :z16
Regards,
David.
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Hi David,
Have sent you a PM with a link to the rod blank manufacturers section on autoclaving in the rod building industry. Means you can peruse when you have time.
As for bubbles in blanks, was that not the problem Hardy had with the original Angel Salmon rods?
Have a read of the webpage I sent..it probably explains this better than I did.
Thanks again, and indeed, back to work :)
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Hi Rob,
Thanks for the link, I was aware of the information. http://www.century.gb.com/technology.php I'll stick with my response I made regarding autoclaving not being used for making rods in post #16. :grin
As for the reasoning behind Hardy Angel rods breaking being bubbles in the wall of the blank? Where did you hear that one?
I worked with Hardy as a consultant for some time on rod design. They may have had breakage issues with certain models. Every company has had issues of one type or another with a design in an attempt at getting the final production model totally user proof. It is inevitable that a volume manufacturer such as Hardy will have a proportion of breakages. I would be certain though, that any breakages on Hardy Angel rods have nothing to do with mysterious air bubbles in the wall of the carbon blank. It just does not happen in the process of making a blank, that bubbles can form or get trapped within the blank wall during the manufacturing process.
Regards,
David.
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okay I'm convinced of the benefits of finding the spline and will take Davids word for it that the spline goes on the same side as the rings. However I have a question about finding the spline. I put the thick end of the section on a hard surface, the thin end on my open palm and then with the other hand roll it until I can find the spline. However I typically feel a resistance to turning and then a jump as it turns. Do I mark it where I find the resistance or the jump if you see what I'm saying?
Thanks
Matt
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Heehee..the joys of spines/splines :)
Its harder to write than view how to do it....so have a look at this..explaines it well :)..although he also talks about the "belly" of the rod as well :z4
http://www.youtube.com/watch?v=LTvyYl2wmOw
You will find there are two areas where the rod bends easier..and two were it jumps. Of the two "easy" ones, one will be very slightly softer than the other..only just mind. You want the rings on the "inside" of this bend...or as he calls it..the belly :)
Hope that helps.
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It should be noted that not everyone agrees with the importance of spine.
It surprises me that so many people say finding it is of utmost importance but can't agree on where to put the guides in relation to it. Some say on it, some say 180' to it and others say at 90' to it. Can they all be correct?
Many people, including many major rod manufacturers say it doesn't make any difference, This is what Dr Steve Harrison of Harrison blanks says about it
"Spines.
Ok, back to spines, excuse the pun.......... First, what is the spine?
Rod blanks are made by rolling a pattern around a mandrel. Like a swiss roll, there is a start and an end to the "roll" and they can produce a hard and soft side to the blank. That is, if you roll the blank whist slightly bent, there can be a feeling of almost a bump in stiffness in one part of the blank. If you hold the tip in one hand and twist with the other, whilst keeping the rod bent, you are most likely to feel this. Holding the rod tip against a wall or floor whilst rolling the rod will do the same. Often the spine coincides with a slight bend in the blank, as ths spine tends to pull a slight curve during the cure. Many builders would say find the stiffest side of the blank, mark it and put the rings in relation to it. But they dont agree where! Some say at 180 degrees to the spine, some say at 90. One going for the stiffest plane, one for the preffered plane of bending. There are arguments for both. I have listened to all the arguments, spent more time thinking about them than most, and I feel I have as good knowledge of the subject as anyone, but I cannot offer you a simple answer. But I do say the following, and this I know is right. Instead of twisting the flexed rod bent over a hand or some other artificial fulcrum, you hold the rod at the handle end, with a weight hanging from the other. That is you load the rod at the tip and hold it at the butt like you do when fishing. Now roll the rod through 360 degrees, and voila, the sensation of the spine has disappeared. Yes, if you do this in a special jig you will detect a tiny variation in the apparent test curve due to a spine, but it is so small you will not detect it in real life. The spine as many rod builders detect it is an artefact of an artificial test. But like a lot of rodbuilding questions, there are no strightforward answers, so talk to someone else about the spine. However, if you want my advice, for what it is worth! Put the blank together and rotate and adjust the sections until the rod is as straight as possible, any natural curve in the rod bending upwards, then place the rings on the underside."
Rod manufacturers such as Sage and Winston follow the above advice. I find it hard to believe that these manufacturers don't know about spine and given the work that goes into making the rods can it be that they just cant be bothered to spend 30 seconds checking for the spine. No, I am sure they think that it doesn't matter.
Lastly Tom Kirkman, top American custom rod builder, writer of many books on the subject and owner / editor of rod builder magazine has also stated that spine makes no real difference and that you should build on the straightest axis.
Tin hat donned :z2
Over to you
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Hi Dave :z16
A tin hat is a good start, but you may like to try a flack jacket :z4 :z4 :z4
It is good that we have so many different ideas on this sort of topic, it keeps the hobby interesting.
Best wishes
Mike
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Rod manufacturers such as Sage and Winston follow the above advice. I find it hard to believe that these manufacturers don't know about spine and given the work that goes into making the rods can it be that they just cant be bothered to spend 30 seconds checking for the spine. No, I am sure they think that it doesn't matter.
Lastly Tom Kirkman, top American custom rod builder, writer of many books on the subject and owner / editor of rod builder magazine has also stated that spine makes no real difference and that you should build on the straightest axis.
I mentioned the above in one of my posts. When a customer picks up a rod, what is one of the first things they do? They look along the rod to see if its straight. As Joe Public, if I am spending £400+ on a rod, I want a straight one :)
If you spend a little time on the US custom forums you will see that many builders build the rod on the straightest plaine for the same reason.
However, this brings the question of the rod sections twisting against each other if the spline/spines are not aligned. Sometimes you hear of anglers who have rods that for some reason, the tips seem to work loose. Many builders put this down to the blank having been built for straightness, not spine.
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okay I'm convinced of the benefits of finding the spline and will take Davids word for it that the spline goes on the same side as the rings. However I have a question about finding the spline. I put the thick end of the section on a hard surface, the thin end on my open palm and then with the other hand roll it until I can find the spline. However I typically feel a resistance to turning and then a jump as it turns. Do I mark it where I find the resistance or the jump if you see what I'm saying?
Thanks
Matt
Sorry for the late reply to your post Matt, I didn't mark this thread for a follow up.
The preferred planes of bending are not an artificial artifact of a test procedure as Steve Harrison states. The guides themselves take the place of the hand or artificial test in actual use.
I never actually refer to where the guides should be placed as the "spine." I always refer to it as the preferred plane of bending. In your example that is the plane it automatically turns to, the jump side, when you bend the blank. The guides should be placed on the outside of that bend. That is the side away from the hand that you are using to bend it.
Using your body as an example, you can bend forward easier than you can bend from side to side, or bend backwards. If your body is the blank, the preferred plane of bending is when you bend forwards. The rings should then go down your back. As I have said previously, If you line up all the preferred planes of bending in each section - particularly beneficial and important on a multi-section fly rod, the rod will track true on the forward and back casts. If you make a clean overhead cast with the rod built this way, It can't do other than track true, you have made the blank totally passive in the way it bends. None of the sections have a bending conflict with the section adjacent to it.
Regards,
David.