Detailed Pyzel Dims

[toddo]

no, that won't get you the numbers that the computer program produces, which is based on a tangent at the mid point length. Nor would it produce you something that you could usefully use to compare your quiver. How the board sits on the floor would vary according to plan shape and be dependent on things such as how much does your tail pad weigh.

Keeping track of the rockers in your quiver is a good way for understanding them though, the only way to do this at home is with a rocker stick (and knowing how to place the rocker stick).

It doesnt matter how you place the rocker stick. It matters that you understand the change in numbers over certain distances.

Likewise a tailpad may weigh the tail of a board down but you can still measure the curve. Eg if its pefectly balanced and its 2.5" tail and 4.5" nose you can see there is 7 inches total. Weigh down the back and it might be 1" tail and 6" nose, still 7 inches total. The more important thing though is interpretting how that 7 inch change occurs. Eg flat with flip, or constant arc.

 

[Mr J]

It doesnt matter how you place the rocker stick. It matters that you understand the change in numbers over certain distances.

Likewise a tailpad may weigh the tail of a board down but you can still measure the curve. Eg if its pefectly balanced and its 2.5" tail and 4.5" nose you can see there is 7 inches total. Weigh down the back and it might be 1" tail and 6" nose, still 7 inches total. The more important thing though is interpretting how that 7 inch change occurs. Eg flat with flip, or constant arc.

toddo if someone doesn't have a rocker stick or the computer file numbers then maybe I should not completely dismiss the idea of looking at how your boards sit on the floor if you feel it helps you understand them.

However you will not be able to compare the numbers with those from computer shapers such as Pyzel. The computer program places the virtual rocker stick on the stringer, so if your board has concave it will be sitting on the rail edges with the stringer elevated. Also pushing down the tail and expecting the nose to rise by the same amount would only work if the rocker range that contacts the floor was a perfect segment of a circle. If say concave accelerated in the tail region then that increases the rail curve and pushing down on the tail would cause a greater nose rise.

The only thing I really agree with what you said is that understanding how say a nose or tail rocker is distributed is important. e.g low entry + high flip or vice versa. The way I do it is to look at the rocker 1' and 6" etc down from nose and up from tail and compare them with a board of similar length as a reference point - this depends upon the rocker stick being placed in the mid point for consistent comparison. When using the computer program the rocker numbers are always generated from a tangent from the mid point. The only choice is whether to choose "in a straight line" or "over the curve". I think most computer shapers use "in a straight line" whereas most hand shapers use "over the curve" because it is easy to lay down a flexible tape measure to get the 1' from nose etc. I suspect most shapers are looking at numbers a known distance from tail and nose - that's certainly what the computer program spits out.

It is also useful to understand whether a board is low nose rocker, high tail rocker or vice versa as it gives boards different ride characteristics. Again a rocker stick or numbers generated from the board mid point is the conventional (and easy) way of doing it.

So how do you understand how rocker is distributed and get measurements to compare boards?

 

[cmogenic]

Does anybody know how much front rocker mid 90s potato chips had? I wish I still had mine to measure.

Steve Coletta's website has a cool rundown comparing shortboard rockers and foils from 1990 and 2000 as well as beyond. His website is minimalist but is bursting with design information. As a side note, he's one of the nicest and most articulate shapers around. http://www.naturalcurvesboards.com/html/designtopics.html#RockersProfiles1990_2020

 

[kool-aid]

see here

Bro, can you please give us the Highline soon?

 

[toddo]

toddo if someone doesn't have a rocker stick or the computer file numbers then maybe I should not completely dismiss the idea of looking at how your boards sit on the floor if you feel it helps you understand them.

However you will not be able to compare the numbers with those from computer shapers such as Pyzel. The computer program places the virtual rocker stick on the stringer, so if your board has concave it will be sitting on the rail edges with the stringer elevated. Also pushing down the tail and expecting the nose to rise by the same amount would only work if the rocker range that contacts the floor was a perfect segment of a circle. If say concave accelerated in the tail region then that increases the rail curve and pushing down on the tail would cause a greater nose rise.

The only thing I really agree with what you said is that understanding how say a nose or tail rocker is distributed is important. e.g low entry + high flip or vice versa. The way I do it is to look at the rocker 1' and 6" etc down from nose and up from tail and compare them with a board of similar length as a reference point - this depends upon the rocker stick being placed in the mid point for consistent comparison. When using the computer program the rocker numbers are always generated from a tangent from the mid point. The only choice is whether to choose "in a straight line" or "over the curve". I think most computer shapers use "in a straight line" whereas most hand shapers use "over the curve" because it is easy to lay down a flexible tape measure to get the 1' from nose etc. I suspect most shapers are looking at numbers a known distance from tail and nose - that's certainly what the computer program spits out.

It is also useful to understand whether a board is low nose rocker, high tail rocker or vice versa as it gives boards different ride characteristics. Again a rocker stick or numbers generated from the board mid point is the conventional (and easy) way of doing it.

So how do you understand how rocker is distributed and get measurements to compare boards?

To account for concave you only need to measure the depth of it at your mesurment point and subtract it from those points then re adjust the number.

I design my rockers in boardcad. Have my whole library to compare. I then cut plywood templates and hotwire my own blanks from a block of eps. When you cut the templates you need to add extra foam along the curve to allow for rail line rocker which has more foam than the stringer line as you described.

You'll also find the rocker tangent doesnt have to be in the middle of the board in shaping programs, you can put it anywhere you damn like, and also move the angle of it.

 

[ehiunno]

I design my rockers in boardcad. I then cut plywood templates and hotwire my own blanks from a block of eps.

This is such a cool idea. Where do you get the massive block of EPS? What's something like that run?

 

[toddo]

This is such a cool idea. Where do you get the massive block of EPS? What's something like that run?

I'm in Australia, get it straight from the polystyrene manufacturing mob. Runs about $50AUD per blank for VH density.

 

[jkb]

To account for concave you only need to measure the depth of it at your mesurment point and subtract it from those points then re adjust the number.

This is how I've been measuring the rockers of my boards. It makes the most sense to me.

 

[Mr J]

To account for concave you only need to measure the depth of it at your mesurment point and subtract it from those points then re adjust the number.

I design my rockers in boardcad. Have my whole library to compare. I then cut plywood templates and hotwire my own blanks from a block of eps. When you cut the templates you need to add extra foam along the curve to allow for rail line rocker which has more foam than the stringer line as you described.

You'll also find the rocker tangent doesnt have to be in the middle of the board in shaping programs, you can put it anywhere you damn like, and also move the angle of it.

BoardCAD was made by a clever person who used to be on swaylocks, one of the early board design programs. I didn't realise it was still going.

Yes, you are right we could just subtract concave depth which is not difficult to do. One way I can think of for getting in a straight line measurements without a rocker stick would be to have a long table. Mark 3 lines for the mid point and the two ends then wedge up the tail until the rails rested exactly on the mid point line and the nose tip and tail end were directly over the end point lines. Maybe it could be done on the floor if one lay down on the floor and got an eyeball as close to floor level as possible - I haven't tried it.

Are you sure you can put the rocker tangent anywhere in the current shaping programs? I don't see it in shape3dX - only buttons to select measurements along "A straight line" or "The Stringer". I am a noob with s3dx though and not used AkuShaper. As far as I know shape3d and Aku are the only ones in common use for CNC cuts - is that correct? Regardless I can't believe that the published rocker measurements such as from CI or Pyzel would be taken from anywhere else. However, if any of the major shapers wants to chime in I am always interested to learn.

 

[Mr J]

This is how I've been measuring the rockers of my boards. It makes the most sense to me.

jkb, I remember you got quite detailed rocker measurements from one of your favourite boards some years ago, did you obtain the measurements without a stick and if so how did you do it?

I remember when I tried to fit a curve to the numbers there was some undulation, they did look basically sensible though. I would expect that sort of inaccuracy even with using a rocker stick - I found it difficult to get meaningful accurate measurements of rocker say 2' down. I ended up just noting the 1' down measurements when trying to assess entry/exit rockers.

 

[toddo]

BoardCAD was made by a clever person who used to be on swaylocks, one of the early board design programs. I didn't realise it was still going.

Yes, you are right we could just subtract concave depth which is not difficult to do. One way I can think of for getting in a straight line measurements without a rocker stick would be to have a long table. Mark 3 lines for the mid point and the two ends then wedge up the tail until the rails rested exactly on the mid point line and the nose tip and tail end were directly over the end point lines. Maybe it could be done on the floor if one lay down on the floor and got an eyeball as close to floor level as possible - I haven't tried it.

Are you sure you can put the rocker tangent anywhere in the current shaping programs? I don't see it in shape3dX - only buttons to select measurements along "A straight line" or "The Stringer". I am a noob with s3dx though and not used AkuShaper. As far as I know shape3d and Aku are the only ones in common use for CNC cuts - is that correct? Regardless I can't believe that the published rocker measurements such as from CI or Pyzel would be taken from anywhere else. However, if any of the major shapers wants to chime in I am always interested to learn.

Im not too familiar with shape 3d but with boardcad and aku you definitely can move the apex location and angle it sits on. Im almost certain you can export a boardcad file to be cut. Cant remember if i have had one cut since switching from aku to boardcad though.

Actually a lot of boards on CI's board selector seem to be more tilted towards the tail compared to what i'd expect the measurements to be compared to others.

 

[jkb]

jkb, I remember you got quite detailed rocker measurements from one of your favourite boards some years ago, did you obtain the measurements without a stick and if so how did you do it?

I remember when I tried to fit a curve to the numbers there was some undulation, they did look basically sensible though. I would expect that sort of inaccuracy even with using a rocker stick - I found it difficult to get meaningful accurate measurements of rocker say 2' down. I ended up just noting the 1' down measurements when trying to assess entry/exit rockers.

No, I use a 6ft level.......but I just use it for its straightness and don't use the actual leveling part.

With the board upside down, I center the level on the boards exact midpoint and tape it down with some painters tape going from one rail, over the top of the level, and to the other rail. Record rocker every 6" or 12". Then I take a straight edge across the board, measure concave depth at each one of those rocker measurements and compensate for the concave depth to give me rail line rocker measurements. Any undulations were most likely me taking a faulty reading or performing faulty math......or both

Sweet looking board Mr. J! I enjoyed watching the glassing vids. Really nicely done!

 

[need 4 speed]

Are you sure you can put the rocker tangent anywhere in the current shaping programs?

Using shape3d to move the rocker apex is very easy, in the bottom pane, the "dot" on the bottom of the rocker can be moved fore and aft.

 

[Mr J]

cheers toddo and n4s, I had no idea that the rocker measurement apex could be moved in aku and s3d. Do either of you move it to look at measurements from a different point?

 

[Mr J]

No, I use a 6ft level.......but I just use it for its straightness and don't use the actual leveling part.

With the board upside down, I center the level on the boards exact midpoint and tape it down with some painters tape going from one rail, over the top of the level, and to the other rail. Record rocker every 6" or 12". Then I take a straight edge across the board, measure concave depth at each one of those rocker measurements and compensate for the concave depth to give me rail line rocker measurements. Any undulations were most likely me taking a faulty reading or performing faulty math......or both

Sweet looking board Mr. J! I enjoyed watching the glassing vids. Really nicely done!

that sounds exactly right jkb. I hope so, that's how I have been collecting measurements of the years. I have been taking measurements based on marks on the board rather than rocker stick i.e over the curve. For comparing just the nose tip and tail end rockers "over the curve" is quite close to "in a straight line", they vary more for measurements further down/up.

For the purpose of feeding numbers into s3d there would be no need to add the concave depth because the s3d numbers are from the stringer not the rails. I didn't know how to import numbers so what I did was fiddle with control points trying to hit your numbers and I could sort of tell which were the outliers. It was an interesting exercise. I was matching your very short tomo board with numbers further down the new target design to extend it as you suggested. Someone I think username Whisperer suggested just scaling it up which is easy, however I like your original idea best because it keeps the exact same "engine room" as what you considered to be a magic board.

Glad you liked my glassing vids JBerry suggested I take some and when shared them to Josh in social media he was rather stocked to see that his hands on tutorials had stuck and I seemed at home working unsupervised in his workshop.

Despite the rocker feeling more bent than I expected and the rails coming out more pinched (machining inaccuracy - I double checked my rail numbers - same as previous 2 incarnations of my design) I am stocked beyond expectations with how it is performing. I am enjoying the different feel from my daily HPSB, got some hard driving turns with deep buried rail (that's what it feels like anyway, reality probably looks different, but as long as I think I'm ripping that's all that matters). It was not a requirement for it to go in small waves, but it goes great in waist to chest high open ocean. I can pump up speed in steep sections and the flat spots lend themselves to repeated cutbacks which the high rocker does nicely. Nailed the fin positions for the Griffin fins too.

A lot of the extra performance comes from taking a really hard edge up several inches forward of the front fins leading edge and the weight and flex. Weighed it before putting a tailpad and fins - about 5lb. I didn't put any carbon on the underneath like previous builds and I think that has a lot to do with it too.

 

[jkb]

For the purpose of feeding numbers into s3d there would be no need to add the concave depth because the s3d numbers are from the stringer not the rails. I didn't know how to import numbers so what I did was fiddle with control points trying to hit your numbers and I could sort of tell which were the outliers. It was an interesting exercise. I was matching your very short tomo board with numbers further down the new target design to extend it as you suggested. Someone I think username Whisperer suggested just scaling it up which is easy, however I like your original idea best because it keeps the exact same "engine room" as what you considered to be a magic board.

I'm not totally sure, but I think my original intention behind getting rail rocker numbers was for handshaping purposes. The thought being I would replicate the rail rocker using a planer across the entire bottom curve first and then add the concave later.

Either that or I was just taking as many relevant measurements I could think of after going down a deep dive on how different shapers obtain rocker numbers.

I still haven't taken the time to dive into S3D that much so I still don't have a very good handle on which numbers are useful and how to use it.........but I've decided I'm going to try handshpaing a board here at some point (hopefully soon).

 

[Mr J]

I'm not totally sure, but I think my original intention behind getting rail rocker numbers was for handshaping purposes. The thought being I would replicate the rail rocker using a planer across the entire bottom curve first and then add the concave later.

Either that or I was just taking as many relevant measurements I could think of after going down a deep dive on how different shapers obtain rocker numbers.

I still haven't taken the time to dive into S3D that much so I still don't have a very good handle on which numbers are useful and how to use it.........but I've decided I'm going to try handshpaing a board here at some point (hopefully soon).

jkb, I think you should follow whatever process you feel comfortable with. Having said that knowing some pro tips does make things a lot easier and more enjoyable. I think every shaper would think that it is an advantage to have hand shaped before trying the computer. I don't think we have many (if any) notable computer shapers who have never picked up a planer, so that point could be considered debatable. Anyone know?

Are you planning on glassing it yourself?

Although the numbers range for putting together say a thruster are now well understood, it's a long road to being able to make oneself a good board, let alone a magic one. Being able to produce magic for others across a range of varying designs is another level of attainment which I am not aiming for.

By all means aim for a good board, but getting one on first build is not realistic. However creating a bad board and riding it is very instructional. For me some of the enjoyment of surfing is not just owning a good board, but trying to understand why it is good.

Unexpectedly I have deemed this years build magic! Since last writing on this thread I have taken it out in the open ocean twice and also ridden my perfect local custom HPSB in a sheltered spot which gives a reference for comparison, so I don't think I am deluding myself. It just felt so good the last 2 days. Resting today, but day before yesterday mixture of wind and groundswell started to build and by the evening the open ocean was a messy overhead on the outside and not looking attractive enough for anyone else. However, there was an almost mirage like left breaking down the side of a particularly big channel, bowling with a short, but defined wall. It really stood out amongst the mess although I knew from experience, that this sort of setup can be near impossible to ride - can't catch the shoulder, bowling face pitching over sand and being able to sit in one place waiting for the wave not possible with the currents. However I got a few and made some to close to shore, some entries into the wave made possible with white water takeoffs and the board just felt great, no feeling of any adjustment being needed.

Yesterday similar conditions, but the channel had disappeared overnight, so I chose another channel, not as good waves as day as before. In conditions like this I sometimes need to abandon my board instead of duckdiving when drifting out on the current to a crunching bar or in the case of yesterday some of the inside waves were unexpectedly crashing onto a shallow sandbar - no one else in the water so bailing board not an issue for others safety. I do a fair bit of this which is why I have been putting carbon on the underneath of my previous pu/pe annual builds - Brett Barley does this with Superbrand step ups. However it does detract from the ride and I glad I left it off this year and learned the importance of flex.

One of the things I got right this year was the fin positions. I could just use the thruster positions McKee publishes, I also have Dave Verrall's positions for his flagship HPSB "Garden Variety" range, but instead I measure the positions of the boards I am riding and make a judgement based on how they are feeling - it is more instructive this way.

Chilli Grom+ is 10 3/4" and 3 5/16" at 1 3/16" from rail - feels perfect.
Local Custom HPSB 10 1/2" and 3 1/4" at 1 1/8" from rail - feels perfect although I was surprised to find out how far back the front fins were.

Mini Bird - 3 7/16" 10 7/8" - feels perfect.
Diverse Garden Variety 10 7/8" 3/18" - on the drivey side but feels good

V1 of my annual build 10 3/4" 3 1/4" at 1 1/4" in - should have been fine but too stiff, although drivey. I had however pointed the fins 2 1/2" from nose and extra 1/2" on say Dave Verrall's 2". Nothing extreme - Rusty reckons can go up to 3" on high rockered boards. This was a moderately rockered board which maybe combined with the extra distance from rail conspired to produce the poor behaviour. Maybe things not right with the shape not helping. So it seems combinations of parameters within the normal range can go wrong.

Last years round tail build perplexing. I chose the exact same positions as the Mini Bird - short round/thumb tail grovel shape. This should have worked I reasoned, because the round tail likes the rear fin a bit further up to compensate from the stiffness of the lost surface area - it still looked rather far up at 3 7/16" on the other hand my round tail was narrower so that would have required the more forward position anyway. I also decided to be conservative with toe in and move it back to 2" and put it a more conservative distance from the rail at 1 3/16". However it was terrible - felt too far forward. This year I chose 10 7/8"and 3 3/16", 2" toe in and the same 1 3/16" from rail and it feels perfect These positions are for Griffin fins, they don't need to work for any other fin and I am not sure they will - the Griffin rear fin has about 1/4" narrower base than the front fins. AM size small are all the same size.

Not sure what to do with next years build apart from make a slight adjustment to the nose rail apex. I could be brave and try a straighter toe in as per Rusty's suggestions for high rockered boards - don't think I would be prepared to try as much as 3" from the nose though.

 

[jkb]

I'd like to glass it myself, but I worry that I'll spend all this time shaping a blank and then just fck it all up by trying to glass it. We'll see how confident I'm feeling after I shape it.

Sounds like you have your preferred fin placement pretty dialed now. Did you ever consider fin systems like 4-way fin system to help dial in those fin placements in your earlier boards? Or perhaps glass-ons that you could cut off and re-position? Do you think that could have salvaged a self shape or two?

 

[Mr J]

I'd like to glass it myself, but I worry that I'll spend all this time shaping a blank and then just fck it all up by trying to glass it. We'll see how confident I'm feeling after I shape it.

Sounds like you have your preferred fin placement pretty dialed now. Did you ever consider fin systems like 4-way fin system to help dial in those fin placements in your earlier boards? Or perhaps glass-ons that you could cut off and re-position? Do you think that could have salvaged a self shape or two?

Some stuff ups on first glass job guaranteed! I enjoy the process of doing the whole lot start to end.

Yes, 4ws are good. I did have some wiggle room with FCS II boxes - I could have put twin tab fin in model 1 and move the rear fin up, but I lived with it. I was able to gain some knowledge from model 2 by moving the twin tab Griffin front fins forward a bit. Its partly optimism of getting it right that I go for FCS II, plus its a good box and I got the jig. Model 1 and 2 were both flawed in other ways though - 2 (last years) particularly. Nailed it on number 3. My second annual build was a twin fin and not part of the current series I am pursuing.

 

[Swallow Tail]

hotCheetos, that's a great idea - use 6' 0" as the industry standard for publishing rocker numbers and get all manufacturers to follow.

thatll never happen. But would be nice to see board makers do it across at least a few of their models to compare to each other. If enough makers start doing this, there will become an expectation of it n everyone will need to start posting numbers.

“medium” or “low” rocker doesn’t mean a damn thing. Numbers do though. & I’d rather see an entry rocker/12” from the tip number rather than just a nose tip number-boards w pretty different rockers can have same tip numbers.