Define usable.
Volume means nothing unless you can correlate small changes to how the board rides. It can only be used as a relative number to compare with a very similar board. So if comparison is the reason for playing with volume, you can use the bulk ellipical method proposed or even do it as a 3D rectangle. Convert the result into a percent difference which will be the same number if estimated as either a box or curved. We all know that performance is the sum of the various design elements, and manipulating volume in any one of them cannot be done without changing something else.
However, if you want to alter certain features and see the volume change, then you need to put the shape into CAD. The CAD system uses a so-called “lofting” process which takes the cross-sections at tail, middle, nose and aligns/constrains them within the outline to generate the developed shape. Each cross-section is 2D so the plane area of each is known to the system. The lofting equation it generates contains the length which is used between each cross-section’s area to calculate the changing volume. A shaping machine needs this lofting equation for the cutter paths, i.e. deck dome, rail shape + bands, rocker, etc. Bottom contours and such are generally separate operations from the basic shape and then subtracted from the basic volume.
3D modeling and finite elements…needed for programming a shaping machine but questionable as a design tool for producing predictable results in how a board performs. That’s why most are hand shapes then scanned. Further, every shaping machine I’ve seen has very rudimentary homebrewed software in terms of real CAD (SolidWorks, AutoCAD). CAM is for tool paths and manufacturing, CAD is for design; they are not directly interchangeable and have to be converted into one or the other.
people should put all this effort on volume into actually grabbing the board, and putting it under the arm.
then if you know what youre doing, youll “feel” if the board will work for you.
volume is for the robot shapers to use for replicating no? thats where it came from so trying to put it into the
vocabulary of a handshaper makes no sense.
as an élément for compare.
I fully agree with lemat here.
I believe volume is a very important measurement, just like fin area, but if you can’t produce your boards accurately it will lead to false conclusions and will do more harm than good.
Also don’t forget that volume errors scale with a power of 3 compared to the errors in length!
This ^^^^^^^^^^^^^^
Besides, volume alone doesn’t tell anything; the way this volume is distributed is far more important. Think of S-decks, no-nose boards, single fins with wide point in front, etc…
Buoyancy varies directly with Volume. I would argue that Volume is the single-best quantifier of buoyancy. Assuming identical core material, i.e. same density, a shape with greater volume will have greater buoyancy. Unfortunately, the volume of an irregularly shaped object, such as a surf craft, defies simple calculation. So, estimates of volume are made, with the accuracy of the estimate varying with the experience that the estimator has, both in handling and using surf craft. Fortunately, we have CAD software that easily calculates volume.
If you surf a 6-0 shortboard or a 9-6 longboard, or both, and have so for years, then “volume” may be a moot point, or seemingly irrelevant. Especially if you’re in that pre-40 age group, and your body weight hasn’t changed for years. Through trial-and-error you’ve discovered the dimensions that yield the buoyancy you require. But if you’re new to the sport, and/or have gained more than a few pounds over the years, your buoyancy requirements are now different. That’s just simple physics. Knowing the volume of your past shapes will help to define the volume of your newer shapes. Is a volume figure absolutely required? No. But just like the computer in my car that calculates, on-the-fly, an estimate of how much further I can travel based on the fuel I have in my tank, my speed and my rate of fuel consumption, it’s a big improvement over “I’m not quite in the red area just before the “E” on the gauge, so I think I can make it to the next town” In other words, it provides more accurate and specific information on which to base a design decision.
Personal Experience: I have been shaping prone boards, aka belly boards, for the past 10yrs or so. The first one I shaped was based on the work of Larry Goddard, and was almost 3" thick. I found this to be way too corky for me, at my weight, and began to evolve the design, reducing the thickness with each iteration. The initial six were all hand-shaped from the smallest blank (at the time) a 5-10RP. Reducing a 5-10 blank to 48"x22.5" x 2.5" produced a lot of waste. And, consistently producing the bottom contours, with seamless transitions was also becoming quite labor-intensive. When I made the switch from PPU to EPS and CNC machining, the design really took off. Through trial-and-error, I was able to reduce the volume to a point where performance suffered, which for me was 21L, I settled on 22L as the ideal volume for my weight. I then built a formula that prescribed volume in a liter per pound body-weight fromat. I did something similar for length. Now, 40-50 prone boards later, I’m able to size a board that is correct for the intended riders body weight and height. Couldn’t have done it as quickly or as successfully without knowing volume.
RANT WARNIG: As an aside, I’ve found that the people who deride the use of CNC shaping tend to be the ones who can’t figure out the software, can’t afford the software, or who don’t have access to a CNC Machine Shop for surfboards. If you been in the industry for any length of time, you know that most professional shapers, with rare exceptions, use CNC shaping for the majority of their production and design. It’s simply a matter of cost-effectiveness and precision. Can these guys handshape? Goes without saying. Do you have to know how to handshape before you can successfully design and finish-shape a CNC’d shape? Absolutely! Does having a shape cut on a CNC machine guarantee a successful design? Of course not!! But then, neither does hand shaping. There are simply times when the CNC machine is the best tool for the job; “Tool” being the operative word. And, like every other tool, including the Skil 100, the Clark Hitachi or a SureForm, the CNC Machine is no better or no worse than the shaper or the machinist using it. END RANT
Well That’s quite a rant 9’er , but you’re entitled to it. I use Volumne as a comparison stat. I don’t figure it. I just ask my cutter what it is. But since I only have three files, all for Shortboard, it does me very little good unless I am up scaling one of those files.
Hi NomasTomas, what you say is so naive and narrow and is exactly the same what all the “big name” guys said in the mid 90s when all turned to the machine.
I can write a response consice enough to help you put a more presice light on the subject but I am tired to this David vs Goliath story and in the end you will still suck those CNC big name raspers and believing what marvelous is all that. (do you remember Kechelle in that sacred craft?)
I don’t believe you can…else you would.
I hand shaped a fish today because I’m a cheap bastard and right now I have a lot of time on my hands. And, hand-shaping is enjoyable, meditative. But, I also enjoy designing shapes in Aku, and seeing that pure abstraction take form on the machine. Of course, I get to tweak it a little here and there by hand, so there’s that, too. But in the end, that big 'ol machine is just another tool. Jim Phillips used a cheese grater to shape his first board…tools are just tools. The “soul” is present in the person using them.
Here’s the thing: this basically IS a volume calculation, but on an intuitive level. You are feeling the rail style and thickness the width and thickness of the board, the overall circumference of the “slice” your arm is on, and those are all greater influences on volume than length (within reason). For most boards, a 1/8 change in thickness at the thick-point will change a board’s volume more than 3" in length. If you were a beginning shaper, and you used Shape3d, paying attention to volume, you would learn this within the first hour of using it, where in life by trial and error (without a mentor) it might take months or even years (if you’re really not bright).
Based on what you input, the calculation will be very accurate “in the abstract.” In reality, yes: the “scrub” and or shaping will alter that volume, but not as much as some of you seem to think, if the file is on point with what you plan to do in terms of the finished board. So, your final product might be out of whack with what the program says, but it won’t be the program’s fault.
You should all download Shape3d and play around with it (quite a bit) before thinking you kinow what’s up, if you haven’t spent time with it. Experienced people might not learn anything new, but all noobs who haven’t will. It’s pretty obvious the majority of naysayers haven’t.
It is a very effective tool to expedite what ol skool shapers had to just accumulate by experience over a much larger exposure to boards over time. The “feedback loop” of having at least rough volume estimations greatly speeds up one’s ability to judge board types for different rider abilities & weight.
I don’t use it that much myself, any more, making a board from myself that isn’t some kind of knock-off, but having used it all the time up to now is a large part of why I don’t feel like I need to. I would bet if I make a board for myself, I can guess its actual (glassed) volume within 3-4 liters (out of around 42 to 52, generally). After I sit on it, in the water, within 2L. I can only do this for shortboards and hybrids under midsize, because I just haven’t done the same kind of repetitions with midsized or LB boards. I have no idea whatsoever what the volume of a 9-0 x 23 x 3 round tail is likely to even roughly be, because I’ve never tried to make a file for one. But I can look at almost any board (in person, eyeball, no under-arm test) and tell you whether it’s over or under 45 if it’s off that by more than 2 or 3L.
To think it’s not a useful tool (volume, or software that gives it to you) is just kind of pointless denial of reality.
NMTomas,
I agree. The computer is a tool. It can augment the human mind and greatly accelerate design and development. For some shapes and designs, hand shaping is not precise enough, practical or cost effective.
Sadly, I just recently discovered most software and CNC equipment used for shaping surfboards have limitations beyond simple curves/contours. But the computer is the only way forward for some of my designs.
Bill
Well Said Tomas… I think reverb tore up your speech. How’s your health these days?
…I am not talking about the Soul etc I am inside this Industry since 35 years ago and know a bit how or why some things were and are done the way that all we know now but you are so indoctrinated that seems useless to spend more time in the subject also I am here to try to share some techniques or learn some new ones regarding other fibers etc that I do not want to “sacrifice myself” in a public forum saying certain things and better to remain silent like other shapers here.
-Also, the machine is not a tool and the guy behind etc; the machine actually do the work whatever guy can be behind. The machine does the passed not your arms or eyes.
Is so indoctrinated that you have there a big factory near Oceanside in California that have a big poster saying “handcrafted”!! all machined.
McDing said in other thread that these guys doing repairs for free are killing the industry; this wrong perception is what is killing this labor.
A used machine is so cheap whatever guy can buy one; in fact plenty I see doing that and then branding. You put Jim Phillips name to have some credibility…I do not see Phillips buying a machine anytime soon.
Again, there are many aspects that changed the landscape in what is the industry now. Politicians do the same and you have MOST of the citizens nodding the heads in agreement possibly you are one of these.
Stoney - I only have experience with Aku, so I can’t comment on the others. Yes, it has some limitations (most notably the inability to shape swallow- or fish-tails) but that limitation allows me to utilize my hand-shaping skills. So, its a “feature” not a “bug”, as someone in computer marketing would spin it. That said, there is still a lot that can be accomplished. Here’s an example below. Note the “DIMS” This prone board was created for a rider 6’2" tall and 230lbs. Using my formula, the target length was 52" and the target volume was 28L. I manipulated width and thickness to achieve the volume. This drawing was created using screen saves taken from Aku’s 3-D “The Bay” function.
MDing - I enjoy your humor…still chuckling. Health is good, thanks for asking, but at 72 I’ve finally lost the ability to pop-up, and if I’m going to be that old guy that ends up riding on his knees, I might as well embrace it. Latest “old surfer” anecdote…volume = 37L in case anybody’s interested.
reverb…thanks for your input…
During the late 90’s I had a friend that had a pretty serious back injury who prone surfed. When he got to the point that he couldn’t any more; He took on the “bad boy” image of our local surf club-- Pismo Beach Longboarders. He drove an old van down to Oceano or the Pier every Sat and set up a coffee table and EZ UP. Always had wax, board or leash for others to borrow. Hot coffee and donuts for after surf. During that time his 15 year old son was probably the hottest Longboarder in SLO County. So he got to surf vicariously thru the kid. I have heard that you and your shop have a following down there. And that you been good to the younger surf crew. We get to the point where the most rewarding thing we can do is encourage the younger crew. Lowel
Free ding repair isn’t killing the industry. But backyarders doing boards for cost and ding repair for free definitely can affect the local market and make it difficult for a guy who depends on those services to keep his head above water.