View Single Post
  #4   Report Post  
posted to rec.boats.building
Mark Reuten Mark Reuten is offline
external usenet poster
 
First recorded activity by BoatBanter: Nov 2011
Posts: 3
Default Flatten/develop plank shapes from lofted offsets

On Monday, 7 September 2015 17:34:13 UTC-7, Dale Rogers wrote:
Hi folks, is there a 'paper' way to develop the 'flat' plank shapes from offsets and lofted lines?


There is but it may not always be perfectly successful. It's referred to as an expansion. it works best on panels that do not have much twist to them or in which you can determine a common point or plane in which the twist occurs. It is best done from a full scale lofting. It's pretty strait forward in the case of a curved transom for instance but becomes trickier when you get into planking.
Howard Chapelle covers it in "Boatbuilding" in his portion on lofting and also in which he applies the plank expansion technique to a grand banks dory lines. For plywood panels, John Teal covers "conical expansions" in his book "Designing Small Craft".
Paul Gartside also discusses conical expansions in a Watercraft Magazine article and explains his builders method which utilizes a simple station mould scale half model.