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67249Scaling designs - Re: [bolger] Scaled-down Single-handed Schooner

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  • lboatman@ymail.com
    Jan 10, 2012
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      Lots of good stuff and very valid points here. Definitely the best solution is to go with stock plans if they meet your needs. Everything else will cost more time and money.

      As Susanne mentions, in my case I had decided that designing the modifications was part of the fun. I also wanted to experiment with materials and techniques. It was extremely educational. I consider the extra time (which wasn't so bad) and the extra money (which was considerable) over building per the stock plans as a combination vacation and tuition. Many builders, especially those building commercially, do not have the time and money to spare.

      Both were reasonable in my case because I was scaling the boat down. Going up (even if my garage had been big enough) would have been unacceptable, mostly because of the amount of wasted plywood. Another thing that helped was the choice of the boat. The SHS' shape is elegant and simple and easy to scale. Other boats, even by Bolger, would have been a lot more work.

      Even with all this extra work, my boat is still a science fair project. I'm extremely confident that it will work out for me, but until its maiden voyage I won't know that for a fact. Whereas if I'd gone with stock plans for a boat that has been around for years, the only question would be my workmanship.

      The process of modifying an established design needs to be approached with great respect. You need to get into the designer's mind to understand their intentions. Only when you understand what they're trying to say can you attempt a translation. I read every Bolger book I could get my hands on, every blog and article about a Bolger boat that I could find. It's not enough to just look at the set of plans you want to modify. For a complete design philosophy you need to study the complete canon.

      Once you've done that, you need to seriously study the existing plans and reverse-engineer every assumption and trade-off that was designed into the original. In a truly elegant design, no component does only one thing. How does changing something affect ALL its uses?

      So I'm definitely not recommending that folks grab any design and start scaling it. The process works and is worth it only for some designs. If you don't know what you are doing, stick to stock plans.

      As for the innovative suggestions for building large boats in small spaces, here's a lady that hasn't met my homeowners' association . Seriously, though, those are interesting options. Unfortunately, in my case, the boat has to live in the garage. Outdoor storage is not an option and I can't afford the marina charges in this area. That actually was one of my trade-offs. The money saved in slip rental would pay for the entire boat (not just the extra costs of modifying the design) in only 8 months.

      In summary, listen to the designer and insofar as is possible, do what they say. Otherwise you're taking your chances.

      Laszlo

      --- In bolger@yahoogroups.com, "Susanne@..." <philbolger@...> wrote:
      >
      > A few notes on Lazlo's project.
      >
      > Making things fit your needs is often a driving force behind design-modifications.
      > If you embark on the effort to build a boat - small or large - it better match your circumstances.
      > Phil would of course counsel caution as to unintended consequences - which can indeed be surprising.
      > Here, in this example, there seems little reason for grand concerns.
      >
      > But Lazlo's case offers both inspiration to get on with realizing your ambitions in good detail, while suggesting several comments to  add to the picture on such modifications by others:
      >
      > 1.)  In many cases, whether doing a smaller or a larger project, time is typically at a premium in the endeavor of building your own boat, from how much you can spent of the project per week or month, to how much overall you will find yourself investing before you get to enjoy the launching.  Lazlo is lucky to have the garage and thus a very short 'commute' to the job, being able to 'steal' a few minutes here and there, in addition to scheduling dedicated hours to great effectiveness.
      >     Modifying the plans has clearly taken its own share of time, here apparently part of the fun Lazlo (and we all) should have planning and building the project.  But this is time invested in not building her.
      >
      > 2.)  Modifications such as the 94%-scale example is less prone to this, but, say, scaling to 107% can indeed cascade to affect both the materials' budget along with the likely man-hours to possibly astonishing/aggravating extends.  Proportional scaling - in all dimensions - will throw off the often intentional maximization of efficient (US-standard!) ply-sheet use, with 4'1" dimensions becoming 'heart-breakers'.  Even if ply-sheet-numbers are less relevant per cost-item than man-hours, doing additional work per assembly-step does add up as well.
      >
      > 3.) The CLC ply-sheet joining gadget is clearly a time-saver over scarfing, but it inherently does throw off any ply-sheet layout-based design by the loss in sheet-length/width per joint, the same way the much more labor-intensive scarfing does.  After having done a bunch of modified 'Payson-Joints' in 1/4", 3/8" and 1/2" during my on-going project, the Payson-Joint will require more care to arrive at a uniform surface-topography, but will use all of each sheet's length and width, with the losses measured in power-planing shavings and dust, not surface-are in inches or centimeters.
      >
      > 4.) Phil has had his fair share of thinking about and designing boats that can by design be built in smaller spaces than their final size suggests is possible.  Beyond his various 'modular' types, together, we did for instance #646 DOUBLE EAGLE, a 40'x20' catamaran, which was built one hull at a time, plus the connecting structure/cabin in a much narrower and lower 48' long shop.  (She is also known as 'Great Sea' out of Alaska).
      >     In some designs not explicitly drawn for modular construction, working around a bulkhead and working with additional (massive ?) butt-joints a 'tail' or 'bow' could be added after the mass of the structure was completed 'inside'.  Cosmetics can be addressed quite 'ruthlessly' to good results, as you learn the ins and outs of doing good finish on smaller and larger areas on the emerging craft.
      >
      > 5.) Finally, building all the smaller bits and pieces, incl. spars, boards and rudders etc. in a modest space to highest plausible degree of finish, this might allow having to plan on the 'full-size' foot-print of the project only for a limited period of time. 
      >      For starters, this would suggest using a nearby industrial space that offers climate-control and security for a cost acceptable for a few weeks/months. 
      >      If that is not doable, and she has to be done at home - do check your local laws on any of these (!) - , based on what we've heard from people who've done any of these options ( and more !), you could then do the 'mad' assembly
      > - outside alongside of the house under light temporary cover with tools and epoxy in/on a rolling chest over-nighting 'inside',
      > - in the back-yard under more solid but temporary cover, after pricing the hourly-rate of a crane to help her 'jump' over the house (install the ballast later...),
      > - bump out the garage-door opening, by opening the unit itself (stored overhead or unhinged) and then inserting a perfectly-fitted 'plug'/'bump-out' in just 1" plywood that adds a few more feet in length to match the un-modified design, but does so without requiring building-permits or quickly raising grief with unsympathetic neighbors.  Add insulation as necessary match your season.     
      >    
      > Folks have done boats in rather improbable places, whether in a motel-room, or a 4-story walk-up Manhattan loft (big window + crane !) 
      >
      > Now back to my project...
      >
      > Susanne Altenburger, PB&F

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