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tech:designing [2012/07/28 17:12] – external edit 127.0.0.1tech:designing [2020/12/09 19:21] (current) – external edit 127.0.0.1
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 Boat design is a serious business which is not to be undertaken lightly. After all, even professionals get it badly wrong a lot of the time. Boat design is a serious business which is not to be undertaken lightly. After all, even professionals get it badly wrong a lot of the time.
-  * [[*:rules|Uk Cherub Class Rules 2005]] Always a good place to start when designing a boat! If you are in //any// doubt about the meaning or possible interpretation of any aspect of the rules please do not hesistate to contact the [[people:gav_sims|Technical Officer]], [[people:patrick_cunningham|Measurement Officer]] or any member of the [[Contact|Committee]].+  * [[*:rules|Uk Cherub Class Rules 2005]] Always a good place to start when designing a boat! If you are in //any// doubt about the meaning or possible interpretation of any aspect of the rules please do not hesistate to contact the [[people:phil_alderson|Technical Officer]], [[people:MK|Measurement Officer]] or any member of the [[Contact|Committee]].
      
   * [[Designers Interview]] Pick up tips from the best.   * [[Designers Interview]] Pick up tips from the best.
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 === Start with an Idea === === Start with an Idea ===
  
-The most important thing is to be familiar with Cherubs, to have sailed in the class and observed how different boats behave, and how you see the benefits of different shapes. Its also helpful to have a starting point - "What I'd like is a boat a bit like an Italian Bistro, but finer at the bow, narrower and with the beam further aft". Maybe you get a [[http://www.sailingsource.com/cherub/images/ib-anot.gif|sketch like this.]]+The most important thing is to be familiar with Cherubs, to have sailed in the class and observed how different boats behave, and how you see the benefits of different shapes. Its also helpful to have a starting point - "What I'd like is a boat a bit like an Italian Bistro, but finer at the bow, narrower and with the beam further aft". Maybe you get a sketch like this: 
 + 
 +{{ :tech:ib-anot.gif?500 |Sketch }}
  
 === Make Sketches === === Make Sketches ===
  
-From there I suggest you arm yourself with a drawing of your starting point and a sketch pad and start sketching ideas. It's important to consider the boat as a whole, not just as sections, profile etc. In order to do this I find it useful to draw waterline and to a lesser extent buttock sections through the boat. You also should have a good idea about how you want the waterlines and buttock lines to look, because this is how the water is flowing past your boat, which in the end is what is most important. I usually start by drawing sections, and then work out the waterlines from them, and then modify the waterlines to nearer what I think I want and alter the sections to suit. Through a few dozen [[http://www.sailingsource.com/cherub/images/ib-modsk.gif|pages of sketches]] you are getting a fairly good idea about what your boat will look like. You'll find as you go through the sketches that your ideas will change, especially as you start converting sections into waterlines and vice versa and get a real feel for how the different factors inter-relate to make a complete boat. Once you get past the initial sketches graph paper starts making a lot of sense for this business of matching sections to waterlines and back again. It sounds like a lot of work - and it is. You need to be thorough though - you are going to be building this boat for six months or more and maybe sailing it for five years. It's a long time to be saying to yourself that you wish you'd thought more about the transom. You want to be able to visualise the underwater shape of the complete boat before you get past this stage.+From there I suggest you arm yourself with a drawing of your starting point and a sketch pad and start sketching ideas. It's important to consider the boat as a whole, not just as sections, profile etc. In order to do this I find it useful to draw waterline and to a lesser extent buttock sections through the boat. You also should have a good idea about how you want the waterlines and buttock lines to look, because this is how the water is flowing past your boat, which in the end is what is most important. I usually start by drawing sections, and then work out the waterlines from them, and then modify the waterlines to nearer what I think I want and alter the sections to suit. Through a few dozen pages of sketches you are getting a fairly good idea about what your boat will look like.  
 +{{ :tech:ib-modsk.gif?500 |}} 
 + 
 +You'll find as you go through the sketches that your ideas will change, especially as you start converting sections into waterlines and vice versa and get a real feel for how the different factors inter-relate to make a complete boat. Once you get past the initial sketches graph paper starts making a lot of sense for this business of matching sections to waterlines and back again. It sounds like a lot of work - and it is. You need to be thorough though - you are going to be building this boat for six months or more and maybe sailing it for five years. It's a long time to be saying to yourself that you wish you'd thought more about the transom. You want to be able to visualise the underwater shape of the complete boat before you get past this stage.
  
 === Detailed Scale Drawings === === Detailed Scale Drawings ===
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 I hope to have a few designs available electronically to give a starting point.\\ I hope to have a few designs available electronically to give a starting point.\\
-   * [[http://www.sailingsource.com/cherub/images/cherub61.hud|Paterson 6a]] 1994 design with flares and snout added to 97 rules. +   *{{:tech:chdesignarticle.zip| Design Drawings}}   
-   * [[http://www.sailingsource.com/cherub/images/jimb97.hud|Unbuilt Design]] This is a 97 rules boat which I've sketched out, loosely based on a Bistro as outlined above. Its not remotely "ready to build" and almost certainly not quick, so be warned!+There is a 1994 1994 design with flares and snout added to 97 rules and a 97 rules boat which I've sketched out, loosely based on a Bistro as outlined above. Its not remotely "ready to build" and almost certainly not quick, so be warned!
  
-Coming later should be Dave Roe's Pasta Frenzy design - when I can make an electronic version.+Coming later should be Dave Roe's Pasta Frenzy design - when I can make an electronic version. 
  
 Jim Champ, 2000 Jim Champ, 2000
  
 *Though I wish I'd got round to building my 1978 Cherub design- when I look at the drawings it bears a distinct resemblance to the highly successful mid 80s Kiwi design Tasman Express! *Though I wish I'd got round to building my 1978 Cherub design- when I look at the drawings it bears a distinct resemblance to the highly successful mid 80s Kiwi design Tasman Express!
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