Month: January 2014
Half Hulls and Computer Models
Ideas come in all sorts of ways, inspired by variations on existing themes, or from problems that need a new solution. They are first recorded in the imagination, and a certain amount of refinement can be done by mental manipulation. Sometimes I lay awake in a quiet environment and rearrange parts of the design, with my eyes closed.
Soon however, it leads to putting the ideas into a visual form, to react to and reconsider. Perspective drawings are a good start, but eventually they give way to some 3D interaction. From the beginning it was my intention to learn bit more about traditional methods of boat building so this lead to making some Half Hulls, like so many boat designers of the past.
Half Hulls are made from a variety of woods, with a combination of cutting, carving, rasping and sanding. Basswood is a favorite of carvers, but I used pine, douglas fir, and cherry because they also shape well and I had large enough blocks. Making only one side allowed a realistic view of the shape, but also made sure that when it was measured and scaled up to full size, the final boat would be symmetrical. Putting them up against a mirror is an interesting way to expand the view to see at least part of both sides.
But Half Hulls are slow to make and modify. The computer has become a tool to do faster 3D drawing and modeling. This is what Jeff Margush began doing with his sophisticated program which lead. In a relatively short time, we were able to make many small changes for review and revision.
Along the way, I also found a 3D computer program called Delftship, that I would recommend to anyone wanting to dabble in boat design. It is available as a Delftship Pro, but is offered in beginner version as a free download with a tutorial. That was good enough for me to start with and it lead to some interesting experimentation.
“Currently”… making progress with helpers Danny Seibert, Brayden Lehman and Hudson Reichanadter.
If reason and calculation are the work of the mind, imagination is the play ground.
Reinventing the Wheel
A story must be told from beginning to end— it simply wouldn’t make sense any other way. And so I figured, with the story of this boat, that it must begin with the beginning. Still, this story is unique in that its ending has not yet been written. We have only the beginning (a life-long dream of building a boat) and the “real-time” progression (a 19-foot speed boat in the makings). Will the dream be fulfilled? Will the boat actually meet the water? Will it sink or swim? Unlike other stories told in retrospect, the risk with this story is that even the author doesn’t know how it will end.
This week, in “real-time,” I hit a road-block with the boat. As often happens on adventures, I met a new friend who was kind enough to come over and give some experienced feedback. Brad Collins grew up building boats with his dad and has gone 100 MPH in a tunnel hull racer.
The first model boat test had gone quite well. I put the 1/5 scale model in the neighbors’ hot tub and loaded some cans and weights to have it settle down to the waterline.
So when he told me that it was too heavy in the back and would sit off-balanced in the water, I thought I just maybe should check it out. Frustrated, I pulled out my sketches. I measured and worked and re-worked formulas. I found out about the definition of a moment arm: “Torque, moment or moment of force, is the tendency of a force to rotate an object about an axis, fulcrum, or pivot.” The fact is a 450 pound motor at the stern can move the Longitudinal Center of Gravity around 2 feet back on my boat, which creates a lot of tip up in front.
Next, it turns out that the 1/5 scale was really a 1/4.5 scale and so the weights I had used were too light and not positioned accurately enough. I filled the bathtub with water and loaded the boat model with soup cans to test it… again.
Brad was right and the real boat was suffering from too much wishful thinking. I should probably wait to write this “chapter” until we are caught up to speed, until after this issue has been (hopefully) neatly resolved. But perhaps it is also important to capture the present tense of this story, as I sit at my desk sketching and figuring, and even I do not know what will happen next.
And so, as I continue to go backwards to document all that has taken place from the beginning until now, I have also decided to show you some glimpses of “real-time,” which we will call our “Currently” series. “Currently”… I am frustrated and determined and reminded that no great under-taking is accomplished without perseverance and commitment.
This is God’s great Redemption. Only He can take all of the threads of our lives, pleasant and difficult, and weave them into a beautiful tapestry. It is too soon to quit.
Defining the Boat
Beginning the Adventure
So how did this dream of a lifetime actually move from the back burner into forward motion? A year ago, after coming to the end of a volleyball coaching chapter, I had one of those rare and brief periods with a bit of unaccounted freedom to sketch and think. About that time, I was talking with my neighbor Doug Martin who told me that my furniture probably looked “fine” to most people. But then he asked, “When was I ever going to build something that roars and races fast?” That question did make my custom cherry, curly maple and ebony stairway, and a tongue and grooved, mortised and tenoned, book-matched curly maple dresser look pretty tame.
As I was mulling this thought over in my mind, I also was telling some friends that I was considering building a boat, but that the thought of it might just be a midlife crisis. One of them was quick to correct me, saying, “Don’t worry, you’re not that young.”
That was enough kick in the pants, and so one day I told a friend Jeff Margush that I was planning to build a boat and had done some pencil drawings. He invited me to come over to his house and put the lines into a 3D CAD drawing. This began a design collaboration of creating lines, making models and reviewing the shape that lasted around four months.
Our wives called these times “play dates,” but they wondered why it was mostly quiet during the process. If you have to ask, you might not understand. The work we did together definitely created a better boat design than what I would have accomplished on my own.
Anyone who starts an adventure with the hope of valuable treasure, knowing the risk of pain or loss, is never really old.