Moving the Widepoint of a Surfboard Template

To move the widepoint, you adapt the method used for resizing a full-size surfboard template (basic math based).  Follow this link for the full-size template method:

http://bgboard.blogspot.com/2016/01/re-sizing-full-size-surfboard-template.html

Basically, you re-size the template as two different sections.  The front section is from the widepoint forward and the rear section would be from the widepoint to the tail.  It is not complicated but takes a bit of thought to see it.

You re-size the length of the front and rear sections of the template independently/separately.   The original template widepoint is the dividing line between the front and rear sections. You increase and decrease the lengths of each section accordingly to move the widepoint forward or backward.

To move the widepoint back 3 inches, you would lengthen the nose section by 3 inches and shorten the tail section by 3 inches.  To move the widepoint forward 3 inches, you would shorten the nose section by 3 inches and lengthen the tail section by 3 inches.  Use the same math-based method you would use to lengthen and shorten a full-size template (see link above).

I may expand this disussion with some diagrams at a later date... 

Surfboard Design Blog -- Directory

Surfboard Rail Profile Template Design

http://bgboard.blogspot.com/2014/03/march-82014-afterr-seeing-recent.html

Re-Sizing a Full-Size Surfboard Template

http://bgboard.blogspot.com/2016/01/re-sizing-full-size-surfboard-template.html

Moving the Widepoint of a Surfboard Template

http://bgboard.blogspot.com/2016/09/moving-widepoint-of-surfboard-template.html

Making a Surfboard Template from a Photo or Image

http://bgboard.blogspot.com/2013/10/picture-to-template-to-resize.html

Ellipse-Based Surfboard Rocker

http://ellipticsurfboard.blogspot.com/2015/11/ellipse-based-surfboard-rocker_13.html

Dolphin Wing: Wing-Tail Surfboard Design

http://bgboard.blogspot.com/2013/08/angular-dolphin-tail-or-wingtail.html

Dolphin Wing/Tail Evolution: aka "Stoneburner Tail"

http://bgboard.blogspot.com/2015/03/dolphinwing-tail-evolution-aka.html

Ellipse-Based Surfboard Rail Profile

http://ellipticsurfboard.blogspot.com/2015/11/ellipse-based-rail-profile.html

Ellipse-Based Surfboard Fin
http://ellipticsurfboard.blogspot.com/2016/03/ellipse-based-surfboard-fin.html

Ellipse-Based Surfboard Planshape

http://ellipticsurfboard.blogspot.com/2015/11/ellipse-based-surfboard-planshape.html

Ellipse-Based Tail Templates
http://ellipticsurfboard.blogspot.com/2015/11/ellipse-based-tail-templates.html

Hotwire Foam Cutter Power Source / Supply & Wire

http://bgboard.blogspot.com/2011/01/i-spent-over-8-weeks-trying-to-find-all.html

Polystyrene Foam Types & Specifications: XPS & EPS

http://bgboard.blogspot.com/2013/12/polystyrene-foam-types-and.html

Paddle-In Hydrofoil (PIH) Surfboard

http://bgboard.blogspot.com/2013/06/scissor-tail-foil-hydrofoil-surfboard.html

Modify Aquarium Air Pump for Vacuum: Whisper AP 150

http://shedtech.blogspot.com/2015/03/modify-aquarium-air-pump-for-suction.html

Resin Warmer: Low Budget

http://shedtech.blogspot.com/2014/12/resin-warmer-low-budget.html

How Much Resin to Laminate a Surfboard

http://shedtech.blogspot.com/2016/06/how-much-resin-to-laminate-surfboard.html

XPS Peel Panel Tests

http://shedtech.blogspot.com/2014/12/xps-peel-panel-tests.html

MountainBoard (MB) & MB-Longboard Hybrids: Custom Assemblies / Builds

http://bgboard.blogspot.com/2013/06/mountainboard-longboard-hybrid.html

Circular Velocity/Acceleration in Ocean Waves & Surfing Physics

http://bgsurfphysics.blogspot.com/2015/05/below-are-some-figuresdiagrams-of.html

Surfable Wave Speed
http://bgsurfphysics.blogspot.com/2016/09/surfable-wave-speed.html

Wave & Surfing Speeds
http://bgsurfphysics.blogspot.com/2018/08/wave-surfing-speeds.html

Surfboard Rail Profile Template Design

March 8, 2014


[Update: November 2015 -- I recently developed an ellipse-based rail profile design method. View at the following link:
http://ellipticsurfboard.blogspot.com/2015/11/ellipse-based-rail-profile.html ]

After seeing the recent resurrection of rocker profile measurement discussions at Swaylocks and the insistence about the correct methodology for precision, I decided to post something beyond my original comments in this thread:

http://www.swaylocks.com/forums/railsrailsrailsrails

It seems that rail design and communicating it are the purview of a mystical realm.  Shape is determined when the rail is grabbed by the "hand" of a shaman.

A surfboard rail profile is no less a "foil" than the leading edge of a wing.

Traditional "surfboard foil" is the change in thickness from nose to tail:

What I refer to as rail profile/foil is the shape of the rail's curve as seen from a width-wise cross section of the surfboard -- depicted below using a NACA wing profile image:

Consistent rail design and replication require nothing more than templates, or a good tool (a contour gauge) for measuring an existing rail profile like this one presented by John Mellor at the following link:

http://www.swaylocks.com/sites/default/files/rail_gauge.jpg

All that is needed for rail profile template design and replication is basic geometry -- a circle and a rectangle -- combined with a drawing curve (french curves or ships curves).   See the diagrams at the bottom of the page.

The circle circumference defines the edge of the rail.  Circle diameter and the location of its center relative to the height of the rectangle create pinched, boxy, up, down, 50/50, 60/40, 70/30, hard or soft rails.  Circle diameter and the location of its center also affect tuck.

Length of the rectangle defines the point of blending with the deck.  Height of the rectangle defines the thickness of the board/blank at any given point.

The circle is placed tangential to the outer wall (height) of the rectangle.  The center is moved up and down the height.  A drawing curve is used to draw two curves that are tangential to the circle and blended with top and bottom (lengths) of the rectangle.

Once created, a single rail profile diagram can be proportionally re-sized for any given board thickness.

The same "tangent angles" (to the rail curve) could be used to define rail bands for any profile -- more geometry.

The geometry is simple. It can easily be done by hand.  But I am sure it would be simple for some CAD jockey to create a program that does this effortlessly.

IMO the realm of surfboard rail profile design is wide open and unexplored.

Simple graphics for illustration are below:

Accept.  Reject.  It does not affect me.

Surfboard Design Blog Directory

http://bgboard.blogspot.com/2016/01/surfboard-design-blog-directory.html