Edit rocker from a blank/ rocker profile


New to this forum and new to boardshaping. I somehow desded to shape my own board. I guess I like doing thing on my own.
It’s a board I will use when on low wind days with a kite. After a lot of reading and thinking sbout my needs i decided to go with a fish shape 6’2. Where i ride the waves are very small, so this would be a fast planing board to cruise around and have fun when wind is not so strong.

I found a fish shspe on greenlightsurfsupply.com (see picture)

I thougt it has quite a normal rocker for being a fish so how can i edit rocker? For example remove 20% ov the value for each “rocker poin” hor how to do it. I dont feel comfortable doing a complte wn rock with my lack of knowledge?

If you som time to spare…please help a superrookie:)


P.s. Tried to do a serach but did not fin relevant threads

I am having a little trouble tracking with your project, intent and spelling-wise.
-Are you intending on buying a blank or making your own blank?
-Are you designing on paper or on the computer?
I would consider getting a complete DIY/BYOB kit with a suitable blank and glassing materials.

Make your board a good 6-12" shorter than the blank, start the board nose near the blank nose and trim length off the tail. Thus you get a lower tail rocker easily without having to tweak the blank rocker a lot.

Yes I realize the content of my last post could be confusing:) drinking an imperial porter or two and writing in foraign language is not the best combination. I finnished the porter and give it a new try.

I want to shape my own board from a block of eps but I like to reduce the rocker from a rocker profile like the one I posted.

No worries Bloke. We’ll blame it on the porter this time :wink:
More questions:
-Designing on paper or on the computer? (repeat)
-hand-held tools or CNC machine?
-Stringer or stringerless?


I got inspired by Andrew w. youtube channel: https://youtu.be/nAnR6EmUR6o
-Thinking of a 4mm plywood stringer.
-cut out the rocker with hotwire cutter ( allready built)

  • shape with hand-held tools
    -tried to use boardcad but I did not really get it to do what i wanted. Did not find it very user friendly. Any other software you can recommend?
  • i thought this first board would be done by copy the outline and rocker from existing board.

The biggest question mark is how to get the rocket right.

Can you get this far?

  1. Extract rocker image from Greenlight data sheet, rotate, flip. Size image so there are no extra pixels for ‘length’ and that bottom rocker apex is middle of picture. Save as image file
  2. Open BoardCAD->New->Funboard
  3. Scale board button ->length=6’3", width 23", thickness 3"
  4. Wait for screen to update, board should get shorter and fatter
  5. Switch from quad view to Profile view
  6. File ->Insert background image->find image from step 1
  7. View->Grid
    At this point your screen should look like the enclosed picture. You can pull the BoardCAD rocker around and see how it compares to the Greenlight image.
    If you go this way, you will need a plan to get it printed…or that also might be the point where it is easier to do this as a full-scale layout with paper, pencil, ruler, and a thin piece of plywood/something to bend to fair the curve. Take the numbers off the screen and get them down on paper, connect the dots, stand back, see if you like it.

Thanks jrandy I will try this!

From ‘everysurfer’ from about 4 years ago, http://www.swaylocks.com/forums/shaping-concave-and-rocker, 5th or 6th post down in the thread. I’m making rocker templates (tail, mid, nose) now based on these thoughts. Within the thread, there is a discussion on fish rocker.

Gunkie, thanks for the link to the old thread.
Too cold 21F/-5C to try walking around the yard with tape measures so I gave it a go in CAD.
I did not design to a specific nose or tail rocker, just let the arcs do their thing.
I think Bloke was looking for a little less rocker, maybe this would work?
I am still a hack regardless of how colorful the pictures turn out…

Hi -
For a basic rocker tweak on a project involving hotwiring your own blank from a block you will be designing a profile that will be transferred to 2 pieces of hard material which will serve as hotwire guides. As everysurfer apparently pointed out along time ago, sometimes it’s easier to just bend something to fit and trace it.

If you have access to a fishing rod, bicycle safety flag, or any kind of bendable material, just plot out the rear and middle of the profile (full size - on masonite) and follow those curves with your bendable material to your desired nose rocker… trace it out, cut and get busy with a sanding block. You could have the hotwire guides cut (both of them) in the time it will take to get a feel for the computer program. Unless you are having the blank cut by a CNC outfit, you will be transferring all of your data by hand anyway. Just try winging it.

And, FWIW, I am not anti-computer or anything. In fact, Jrandy just finished helping me out with a computer design of a blank file that was cut by USBlanks. He definitely knows his stuff and is a very helpful guy in these matters! Thanks again Jim!

Thanks Gunkie for that cool idea and a big thanks to jrandy for the visual presentation. That rocker actually looks like something I had in mind.
Johnmellor yes that is exactly how I was planing to do the cutting. Cheers guys!


The jrandy/johnmellor methods certainly give you tools to create any curve you want, and going through the process of doing this yourself will certainly encourage good eyes. However, I have some premade rocker profile templates if you’re looking to skip having to become intimate with certain SW programs. No doubt all steps in the process of board building inform the others, no matter the order or timing.

A sneak preview of a 6’3" (4.5"N / 1.75"T) below.

PM me your email address or email me at blendingcurves@gmail.com and let me know if you have specific dimensions in mind.



I like this thread, we are up 4 ways to lay out a rocker template:

  1. Lofting with a batten (bent stick)
  2. CAD, shaping software or 2D
  3. full scale radii templates
  4. Blending Curves template (Andrew makes nice templates, using one of his fin templates right now)

I need to excuse myself as any sort of ‘expert’ on rocker, I am just an enthusiast/hack who gets a kick out of trying new ways of doing things and passing what information I have along. I am still trying to get better designing and building, and I am still an absolute klutz in the water…

Yes it’s fantastic! Really good advices and help from you guys. I hope to start the building process next week. We will shortly see how it turns out. At least it will float, so the kids can play around with it:)


Thanks for all ideas and help. This is after hotwireing and outline cutting.

Looking good Bloke!
Are you going to make rail bands with the hot wire or move on to an electric planer or ???

Looks good. Nice work on the hotwiring.

In the future just send us your rocker adjustments or custom rocker dimensions. We cut customs all the time for customers on our CNC hotwire. No problem.

Now shape that puppy up!

Thanks! I used a surfoam tool for the rough work on the rails. Continued with sandpaper on a block of wood. Not the fastest method, but all I have is time. I might concider a electric planer for next board.
Thinking about ordering kvickkick epoxy. Seems to be good stuff. Or?

Yeah Brian it would be cool too but it’s a long way to scandinavia. Shipping, customs and other dreary things.

Keep on keepin on…

Resin Research Kwik Kick is good stuff. Will you be able to have the resin and the board in a work area that is warm, like 75-80 F or 23-25 C ?