Scaled Model

[beekeeper]

When designing a boat or questions about changes in a build it is often advised to build a scaled down version. Anybody have any pointers or tips?
I'm working with a 1\2 scale pirogue. I have cut the arch in the sides to adjust the rocker. The beam and flare is where I want it to be. Max. beam is 8" behind center. as is the highest point of the arch in the chine. The rocker is not enough and the stern rocker is less than the bow. I want it to be equal or more. How should I re cut the sides to make the changes?

 

[jdupre']

Bee, we didn't talk about the wood you're using for the i/2 scale model. Depending on the thickness, it probably won't bend the same as the full sized version. I'd say, for the rocker , just take off wood to get the rocker you want. Transferring that same curve to the full size boat might be a little tricky.

 

[beekeeper]

My goal for this little adventure was to develop a pattern.that I could use to build a copy of my last boat with the chine logs attached to the sides. I made a full size pattern by tracing the sides onto some thin plywood. These should work but I wanted to make the model process work for when I designed something new.
The scaled down version does not match the boat's features.
I'm using 5mm Luan and it seems to bend well and has a fair shape. Looking at the arch, I am going to move the maximum cut forward. This looks like it will straighten the rear chine line some and should increase the rocker.

 

[jdupre']

That sounds about right. You might also be able to cheat a little by increasing the flair out towards the end that you want more rocker.

 

[beekeeper]

Bingo! It is correct now.
Did not move the arch highest point. I removed some material from each end until the rocker was correct. Remeasured the boat's and pattern and realized the arch highest point was correct.The line to the stems just needed to be flattened. The chine edge and rocker now match the boat and pattern. I now need to cut the sheer line to match the boat.
Lessons learned, so far: Know what the actual specifics you want or need. I had measured the rocker incorrectly. When working with scaled down models any mistakes will be amplified. Accurate measurements and cutting is critical if precision is important to you.