Ha!!! a "smartified" Bonzo. That's great! Makes good sense in a twisted way. Data can be valuable, data can be tragically misleading. I would really like to measure the "gooosh" feel that a board has as it loads up through a serious bottom turn. Perhaps a Field test bottom turn board set up with strain gauges and Plasti gage to interpret loads. We could find out how much the board is bending and twisting, then reproduce it in the lab. Then as we find a super good bottom turning Field board, we could measure it in the lab under load and perhaps measure WHY it is so good. As a board is loading up through a bottom turn (acting like a spring) the water rushing beneath it is also acting like a spring as well; a spring that varies in energy retention with speed. You know, when you are really moving fast and you eat it and skip on the water before penetrating. Higher speed=less spring. Water is hard to model. I had access to an incredible computational dynamics program that would model such a thing fairly accurately, giving a visual data output, but that was years ago when I was involved with some serious Defense projects; no more access. Any one out there have something like that? Anyways, the last important thing is physical modelling. Scale factors must always consider that the medium (water) does not change as we down-scale, ie. density of the water stays constant. Reynolds numbers must be utilized to change the physical shape of the model to compensate for the change in flow. It could be very possible that the model will not look anything like the actual surfboard anymore. I was quite surprised when I saw this in other modelling studies. Lastly, it has been my experience that testing is expensive, and always much more expensive than I anticipated. To get an accurate depiction of what is happening will validate the data and this will take consistency and tenacity. I'm feeling burned out just typing this, I think I'll keep being a lackey chimp / factory robot and just test my stuff out in the water... ...who needs Shakespeare anyway.
Uhmmmm...let me see if I'm following you correctly: Mebbe analyse/model some successful boards, then go from there, as a start, anyhow. Indeed, it's the only way to get any ideas if the numbers you're coming up with are really useful. I like the idea of measuring strains via a strip of something that'd permanently and easily elongate. Could see, for instance, how close a given lamination was coming to failure, though it'd mebbe assume that the deck ( or the other side, anyhow) wasn't compressing to any real extent. Though something could be worked out, mebbe another strip that'd compress. I think the desktop PCs are coming along to such an extent that the kind of electronic horsepower was used for defense projects and Cup hull modelling will be available pretty quick over the counter, though I have seen some used recently...you just have to be kinda patient. A reasonably quick Linux box, running what's probably Unix/C software that's out there someplace ready to download....... Though...if I'm remembering right, those were all for displacement hulls, dunno if there's anything for planing hulls. Which leads to an 'oh damn' moment, a whole set of software I'd just a soon not think about developing. Apropos of nothing at all, you may have run across the Barnes Wallis experiments, trying to get bombs to bounce off water. Probably not applicable, but you never know. Same sort of thing, there's stuff out there for hydrofoil design, and the differences between that and software for airfoil design might be useful. Damn...this means I'm gonna have to crack the books some...... oh well, it was getting a little dull, up here in the trees, scratchin' and waitin' for the bananas to get ripe.....
What ever you do dont trip over a Penguin..... The only way we could see to measuring speed accurately was to have a predictable wave generated that would reliably have a consistant height, thickness, speed and density...Upon creating a reliable wave a rider with reflective surfaces could be laser clocked.....using different boards built for the particular wave one could be raced against the next untill critical speeds are logged from each flow form. Then go to the graph and there will be a representation of each of the boards performances top speed, accelleration, stall speeds everything........ Another way is this.....Jet ski toein boards have lead in them so as to be able to achive speeds of 80km to 120km for runniing into a big wave. So useing a Jet ski and a tow rope you could cheaply and effectively find a straight line top speed.....Although waves are not flat you still would get a feel for the boards stability and speed limits. In Pauls opinion conventional speed boards will reach a max of 60-70km before the shape delams, FP we predict will exceed 70km... http://www.geocities.com/wunderboyi/ninetysixpercent.html
One last bit of energy... That's right, two visually identical boards but one is "okay" and the other "magic". Set the boards up with adhesive strain gauges and clay-rod Plastigage. Take the boards out and have a consistent surfer bottom turn in a consistent manner at a consistent spot. Acquire data numerous times for each board. Go in right after each bottom turn; discipline. Establish load profiles for each board (an average of many sessions). Important: In the lab, place static loads on a board so that it is bent the same way as during the "snapshot" of the bottom turn. Note that we are translating the loads of a dynamic situation and representing them by static (constant) loads in the workshop. Stare at the boards. My rudimentary tests from 20 years ago showed bending in excess of 2"!!! This is over 2G. ("G" is a dynamic load, so a 170lb rider is imparting a 340lb load (static)). Moment of truth: one board looks a little different that the other while sitting there in "bent" profile in your shop. In order to make the "kinda good" board bend like the "magic" put in some carefully metered kerfs until the static profiles match. Test. Voila, control of the bottom turn "feel" has been mastered. During all this a smart monkey makes the comment that the rocker is straight through a certain line in the bottom of the board. Shaping to this, MORE control of the "feel" is realized. With bottom turns tested move on to cutbacks. Off-the-lips. Pumping for speed. Each aspect is cleverly recorded and mastered. Now implant a microprocessor and gyro/accelerometer sensor set that is tied to a T-alloy (the metal that changes shape w/voltage(heat) wire harness. The harness is just a bunch of fine metal rods anchored along certain crucial load lines; these rods contract when a voltage is run through them. Glass the board with a less rigid, low modulus composite shell. Entire ride profiles could be downloaded to the board right on the beach (Laptop). Profiles could be made for specific breaks and during specific conditions. Telemetry updates for changing tide, water texture, wave period etc could be made during the session through the subscriber service. With millions of dollars at stake, the top corporations program their factory riders' boards with more zeal than Toyota does at Pike's Peak. Complete control. Everything optimized in real time. Retro parallel processor surfboards come back into fashion as a "soul resurgence" makes the latest hyperkinetic alloy jobs passe. Telemetry espionage; controversy. Keeping the bored masses awake until the next subliminal commercial media loop tells them what they want. I don't know; I might start doing crochet or something...
yah, I'm kinda running low on zip myself, so the ol' brain may not be firing n all cylinders......... Given a deformation of X from a single point load on the deck and two supports underneath, what would the required force be to bend that de facto beam to X given what seems to be support under the whole thing, given that the water is exerting some force along the entire immersed section of the turning board. Might be an interesting, and easier, move to wire in pressure sensors rather than strain gauges. And there's cute little gizmos like the Basic Stamp line of microcontrollers/single board computers - quite small, build a black box for the board to do data recording. You can configure 'em to measure and record all kinds of stuff at what intervals you want - synch the clock with, say, the clock built into the video camera you have set up on the beach. Make that harness a little stronger, maybe use some of the muscle wires they use in model robotics and the like, or simply rig the board with some gizmos like they use to tune guitars: voila, tunable and variable flex. The guy wire/stiffener matrix doesn't have to be just paralell to the centerline...... parabolic or hyperbolic patterns..... hmmm......... adaptive..... jeez, you're as nuts as I am. this could get dangerous. http://www.parallax.com/
Its a real hoot reading all this stuff about tank testing. Why don't you search the internet for starters ..... Go to the report suggested below and follow the references around. Some of this data goes back to the 1950's, and its all free. If you look hard enough, you will find that a planing board is mathematically equivalent to the lower half of a wing. You will also find somewhere that rounded chines (rails) reduce lift. You will also find that concave increases lift. So go find out for yourself. Just please note that this information is not served up on a plate for you. Get going. http://naca.larc.nasa.gov/reports/1958/naca-report-1355/naca-report-1355.pdf
Clocking some video with data collection; GENIUS!!! (we just quadrupled the test budget). Seriously, one test I did years ago was to find the most crucial load line. By the seat of my pants I found it NOT to be parallel nor parabolic. It was torsional: An "X" pattern starting at the front foot and extending just behind the front fins (Tri). Twist is the enemy but longitudinal flex is our allie. If you know what Luder's Bands are then you know how to overcome this torsion. Guess what the WORST load pattern is? It's the one that promotes torsion and stifles straight bending. That's right, Bi-directional cloth, it lets things twist (BAD) and reduces straight bending (also BAD). Answer?(other than 45 degree orientation): Tri-axial weave, I have a line on some that is low enough in weight (the stuff used on the B-2, F-18 and F-23 and others is too heavy at 18+oz.) but it is still being set up somewhere in the Carolinas. I used carbon graphite uni tape from ACP and was noticibly successful. There are also shape-associated behaviors to consider (anti-clastic behavior). Not enough time right now to elaborate. I'll try to fill the gaps in the next day or so...
interesting dono where your gonna find the budget for some of that testing ...but at the end of the day nothing is impossible... impressed as well with the multi faceted thought processes of some of you guys ... as good as data is ,dont forget the wealth of knowledge that exists in the brains of shapers world wide which came through traditional trial and error see what works approach... but mixed in with that is the probability that some got it wrong ....as a board designer your basic fundamental understanding of what is actually happening is crucial ,if what you think is happening for a particular reason is wrong and the basic concepts you base your designs on are flawed ,it can leave you frustrated and keep surfboards spinning in your brain all night and leave you with out sleep ...and thats where testing and collecting data can help . isolate your variables .............. when learning about different aspects of design you need to keep everything identical except for 1 thing ...simple example is changing fins on the same board nothing changes but the fins ... or every thing stays the same but slightly differing outlines .other wise what you think might be making the difference is actually something else...ok thats pretty obvious stuff .eventually you find combinations will or definatly will not work together.it all takes time ,i think thats why most of the worlds best shapers are old guys... always test your theorys by trying to disprove them .you can do a thousand experiments to prove something is right .it only takes 1 experiment to prove it wrong . so after trial and error testing ,other types of testing can help you build a basic picture of whats happening .... once you have conquored basic design principles and laws of physics, it becomes as easy as learning to spell coz youve learnt the alpabet,or doing maths coz youve learnt to count.... but if you dont learn your alphabet or learn to count properly, then grasping higher concepts will be impossible and confusing and will lead to poor results.... also one more point .... stay on earth, you can go along way in your mind . but the reality is we all need to make a living and pay the bills ,and try and make some sort of progress that is within our reach with the resources we have .... regards BERT sorry if that sounded a little know it all ,but after spending the time to write it i have to post it.....
This has been a fascinating thread and I feel like a minnow contributing. But it seems to me that Tank testing assumes that everybody wants the same thing. (1) Its ok for aircraft where the object is to get from a to b as quickly as possible. How many shapers shape only 1 type of board, for a single rider. (2) As previously stated by others the wave parameters are too varied, height, Direction shape Seabed wind tide rips. rider These all change not for a beach but for different positions on each individual wave. So empirical evidence gathering is the only feasible way. (3) All you can ever hope to achieve is: In a perfect wave, how effective is each feature, and how does it affect other features, for a particular board size. Useful, but the knowledge is there its just that the numbers are not. (4) a component based approach may help, snap on rails, rockers, bottom designs, and it seems to me to be quite doable, using mini cell foam or something, particularly with CNC tools (5) There has been so much R&D into boards over the last 30 years, I believe that there are only going to be incremental changes, like the aircraft or automotive industry. There may be better surf craft developed but I don't think they will be what we know as general use stand up surfboards. eg waveskis with hydrofoils, or 16ft boards towed into open unbroken ocean waves to get the longest rides. It all comes back to the rider,the human body is so incredibly accommodating. No matter what you build somebody somewhere will make it work for them. Like me noseriding yesterday on my nose and tail kicked 50/50 railer with belly right through. Just look at the range of devices for noseriding at the moment some swear by them and others hate them. Bert seems to identified the key features in his boards and they suit competitors, fair dues, but I'll bet he got there by stripping out what was not needed and blending what was left. So, know the people and the waves you shape for and be critical when adding features, the information is probably there on swaylocks. As Einstein said ablot relativity: "To these fundamental laws there yields no logical path, simply intuition combined with being sympathatetically in touch with experience"
nice comment .... shape what your customers need to help them in their quest for enjoyment...but dont shape them what they want ,coz most surfers dont know whats good for them....if a customer wants a board you know wont work for him or hes been misinformed dont do it, better to never build a bad board ...dont forget you the shaper are always to blame ....thats where all this knowledge comes in handy ,the more you learn and understand the better success ratio you get .... regards BERT hey halycon ill send you an email ....you sound like a real switched on dude...
Ha!!! a "smartified" Bonzo. That's great! Makes good sense in a twisted way. Data can be valuable, data can be tragically misleading. I would really like to measure the "gooosh" feel that a board has as it loads up through a serious bottom turn. Perhaps a Field test bottom turn board set up with strain gauges and Plasti gage to interpret loads. We could find out how much the board is bending and twisting, then reproduce it in the lab. Then as we find a super good bottom turning Field board, we could measure it in the lab under load and perhaps measure WHY it is so good. As a board is loading up through a bottom turn (acting like a spring) the water rushing beneath it is also acting like a spring as well; a spring that varies in energy retention with speed. You know, when you are really moving fast and you eat it and skip on the water before penetrating. Higher speed=less spring. Water is hard to model. I had access to an incredible computational dynamics program that would model such a thing fairly accurately, giving a visual data output, but that was years ago when I was involved with some serious Defense projects; no more access. Any one out there have something like that? Anyways, the last important thing is physical modelling. Scale factors must always consider that the medium (water) does not change as we down-scale, ie. density of the water stays constant. Reynolds numbers must be utilized to change the physical shape of the model to compensate for the change in flow. It could be very possible that the model will not look anything like the actual surfboard anymore. I was quite surprised when I saw this in other modelling studies. Lastly, it has been my experience that testing is expensive, and always much more expensive than I anticipated. To get an accurate depiction of what is happening will validate the data and this will take consistency and tenacity. I'm feeling burned out just typing this, I think I'll keep being a lackey chimp / factory robot and just test my stuff out in the water... ...who needs Shakespeare anyway.
Uhmmmm...let me see if I'm following you correctly: Mebbe analyse/model some successful boards, then go from there, as a start, anyhow. Indeed, it's the only way to get any ideas if the numbers you're coming up with are really useful. I like the idea of measuring strains via a strip of something that'd permanently and easily elongate. Could see, for instance, how close a given lamination was coming to failure, though it'd mebbe assume that the deck ( or the other side, anyhow) wasn't compressing to any real extent. Though something could be worked out, mebbe another strip that'd compress. I think the desktop PCs are coming along to such an extent that the kind of electronic horsepower was used for defense projects and Cup hull modelling will be available pretty quick over the counter, though I have seen some used recently...you just have to be kinda patient. A reasonably quick Linux box, running what's probably Unix/C software that's out there someplace ready to download....... Though...if I'm remembering right, those were all for displacement hulls, dunno if there's anything for planing hulls. Which leads to an 'oh damn' moment, a whole set of software I'd just a soon not think about developing. Apropos of nothing at all, you may have run across the Barnes Wallis experiments, trying to get bombs to bounce off water. Probably not applicable, but you never know. Same sort of thing, there's stuff out there for hydrofoil design, and the differences between that and software for airfoil design might be useful. Damn...this means I'm gonna have to crack the books some...... oh well, it was getting a little dull, up here in the trees, scratchin' and waitin' for the bananas to get ripe.....
What ever you do dont trip over a Penguin..... The only way we could see to measuring speed accurately was to have a predictable wave generated that would reliably have a consistant height, thickness, speed and density...Upon creating a reliable wave a rider with reflective surfaces could be laser clocked.....using different boards built for the particular wave one could be raced against the next untill critical speeds are logged from each flow form. Then go to the graph and there will be a representation of each of the boards performances top speed, accelleration, stall speeds everything........ Another way is this.....Jet ski toein boards have lead in them so as to be able to achive speeds of 80km to 120km for runniing into a big wave. So useing a Jet ski and a tow rope you could cheaply and effectively find a straight line top speed.....Although waves are not flat you still would get a feel for the boards stability and speed limits. In Pauls opinion conventional speed boards will reach a max of 60-70km before the shape delams, FP we predict will exceed 70km... http://www.geocities.com/wunderboyi/ninetysixpercent.html
One last bit of energy... That's right, two visually identical boards but one is "okay" and the other "magic". Set the boards up with adhesive strain gauges and clay-rod Plastigage. Take the boards out and have a consistent surfer bottom turn in a consistent manner at a consistent spot. Acquire data numerous times for each board. Go in right after each bottom turn; discipline. Establish load profiles for each board (an average of many sessions). Important: In the lab, place static loads on a board so that it is bent the same way as during the "snapshot" of the bottom turn. Note that we are translating the loads of a dynamic situation and representing them by static (constant) loads in the workshop. Stare at the boards. My rudimentary tests from 20 years ago showed bending in excess of 2"!!! This is over 2G. ("G" is a dynamic load, so a 170lb rider is imparting a 340lb load (static)). Moment of truth: one board looks a little different that the other while sitting there in "bent" profile in your shop. In order to make the "kinda good" board bend like the "magic" put in some carefully metered kerfs until the static profiles match. Test. Voila, control of the bottom turn "feel" has been mastered. During all this a smart monkey makes the comment that the rocker is straight through a certain line in the bottom of the board. Shaping to this, MORE control of the "feel" is realized. With bottom turns tested move on to cutbacks. Off-the-lips. Pumping for speed. Each aspect is cleverly recorded and mastered. Now implant a microprocessor and gyro/accelerometer sensor set that is tied to a T-alloy (the metal that changes shape w/voltage(heat) wire harness. The harness is just a bunch of fine metal rods anchored along certain crucial load lines; these rods contract when a voltage is run through them. Glass the board with a less rigid, low modulus composite shell. Entire ride profiles could be downloaded to the board right on the beach (Laptop). Profiles could be made for specific breaks and during specific conditions. Telemetry updates for changing tide, water texture, wave period etc could be made during the session through the subscriber service. With millions of dollars at stake, the top corporations program their factory riders' boards with more zeal than Toyota does at Pike's Peak. Complete control. Everything optimized in real time. Retro parallel processor surfboards come back into fashion as a "soul resurgence" makes the latest hyperkinetic alloy jobs passe. Telemetry espionage; controversy. Keeping the bored masses awake until the next subliminal commercial media loop tells them what they want. I don't know; I might start doing crochet or something...
yah, I'm kinda running low on zip myself, so the ol' brain may not be firing n all cylinders......... Given a deformation of X from a single point load on the deck and two supports underneath, what would the required force be to bend that de facto beam to X given what seems to be support under the whole thing, given that the water is exerting some force along the entire immersed section of the turning board. Might be an interesting, and easier, move to wire in pressure sensors rather than strain gauges. And there's cute little gizmos like the Basic Stamp line of microcontrollers/single board computers - quite small, build a black box for the board to do data recording. You can configure 'em to measure and record all kinds of stuff at what intervals you want - synch the clock with, say, the clock built into the video camera you have set up on the beach. Make that harness a little stronger, maybe use some of the muscle wires they use in model robotics and the like, or simply rig the board with some gizmos like they use to tune guitars: voila, tunable and variable flex. The guy wire/stiffener matrix doesn't have to be just paralell to the centerline...... parabolic or hyperbolic patterns..... hmmm......... adaptive..... jeez, you're as nuts as I am. this could get dangerous. http://www.parallax.com/
Its a real hoot reading all this stuff about tank testing. Why don't you search the internet for starters ..... Go to the report suggested below and follow the references around. Some of this data goes back to the 1950's, and its all free. If you look hard enough, you will find that a planing board is mathematically equivalent to the lower half of a wing. You will also find somewhere that rounded chines (rails) reduce lift. You will also find that concave increases lift. So go find out for yourself. Just please note that this information is not served up on a plate for you. Get going. http://naca.larc.nasa.gov/reports/1958/naca-report-1355/naca-report-1355.pdf
Clocking some video with data collection; GENIUS!!! (we just quadrupled the test budget). Seriously, one test I did years ago was to find the most crucial load line. By the seat of my pants I found it NOT to be parallel nor parabolic. It was torsional: An "X" pattern starting at the front foot and extending just behind the front fins (Tri). Twist is the enemy but longitudinal flex is our allie. If you know what Luder's Bands are then you know how to overcome this torsion. Guess what the WORST load pattern is? It's the one that promotes torsion and stifles straight bending. That's right, Bi-directional cloth, it lets things twist (BAD) and reduces straight bending (also BAD). Answer?(other than 45 degree orientation): Tri-axial weave, I have a line on some that is low enough in weight (the stuff used on the B-2, F-18 and F-23 and others is too heavy at 18+oz.) but it is still being set up somewhere in the Carolinas. I used carbon graphite uni tape from ACP and was noticibly successful. There are also shape-associated behaviors to consider (anti-clastic behavior). Not enough time right now to elaborate. I'll try to fill the gaps in the next day or so...
interesting dono where your gonna find the budget for some of that testing ...but at the end of the day nothing is impossible... impressed as well with the multi faceted thought processes of some of you guys ... as good as data is ,dont forget the wealth of knowledge that exists in the brains of shapers world wide which came through traditional trial and error see what works approach... but mixed in with that is the probability that some got it wrong ....as a board designer your basic fundamental understanding of what is actually happening is crucial ,if what you think is happening for a particular reason is wrong and the basic concepts you base your designs on are flawed ,it can leave you frustrated and keep surfboards spinning in your brain all night and leave you with out sleep ...and thats where testing and collecting data can help . isolate your variables .............. when learning about different aspects of design you need to keep everything identical except for 1 thing ...simple example is changing fins on the same board nothing changes but the fins ... or every thing stays the same but slightly differing outlines .other wise what you think might be making the difference is actually something else...ok thats pretty obvious stuff .eventually you find combinations will or definatly will not work together.it all takes time ,i think thats why most of the worlds best shapers are old guys... always test your theorys by trying to disprove them .you can do a thousand experiments to prove something is right .it only takes 1 experiment to prove it wrong . so after trial and error testing ,other types of testing can help you build a basic picture of whats happening .... once you have conquored basic design principles and laws of physics, it becomes as easy as learning to spell coz youve learnt the alpabet,or doing maths coz youve learnt to count.... but if you dont learn your alphabet or learn to count properly, then grasping higher concepts will be impossible and confusing and will lead to poor results.... also one more point .... stay on earth, you can go along way in your mind . but the reality is we all need to make a living and pay the bills ,and try and make some sort of progress that is within our reach with the resources we have .... regards BERT sorry if that sounded a little know it all ,but after spending the time to write it i have to post it.....
This has been a fascinating thread and I feel like a minnow contributing. But it seems to me that Tank testing assumes that everybody wants the same thing. (1) Its ok for aircraft where the object is to get from a to b as quickly as possible. How many shapers shape only 1 type of board, for a single rider. (2) As previously stated by others the wave parameters are too varied, height, Direction shape Seabed wind tide rips. rider These all change not for a beach but for different positions on each individual wave. So empirical evidence gathering is the only feasible way. (3) All you can ever hope to achieve is: In a perfect wave, how effective is each feature, and how does it affect other features, for a particular board size. Useful, but the knowledge is there its just that the numbers are not. (4) a component based approach may help, snap on rails, rockers, bottom designs, and it seems to me to be quite doable, using mini cell foam or something, particularly with CNC tools (5) There has been so much R&D into boards over the last 30 years, I believe that there are only going to be incremental changes, like the aircraft or automotive industry. There may be better surf craft developed but I don't think they will be what we know as general use stand up surfboards. eg waveskis with hydrofoils, or 16ft boards towed into open unbroken ocean waves to get the longest rides. It all comes back to the rider,the human body is so incredibly accommodating. No matter what you build somebody somewhere will make it work for them. Like me noseriding yesterday on my nose and tail kicked 50/50 railer with belly right through. Just look at the range of devices for noseriding at the moment some swear by them and others hate them. Bert seems to identified the key features in his boards and they suit competitors, fair dues, but I'll bet he got there by stripping out what was not needed and blending what was left. So, know the people and the waves you shape for and be critical when adding features, the information is probably there on swaylocks. As Einstein said ablot relativity: "To these fundamental laws there yields no logical path, simply intuition combined with being sympathatetically in touch with experience"
nice comment .... shape what your customers need to help them in their quest for enjoyment...but dont shape them what they want ,coz most surfers dont know whats good for them....if a customer wants a board you know wont work for him or hes been misinformed dont do it, better to never build a bad board ...dont forget you the shaper are always to blame ....thats where all this knowledge comes in handy ,the more you learn and understand the better success ratio you get .... regards BERT hey halycon ill send you an email ....you sound like a real switched on dude...
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