stretching a design: adjusting the end stations?

[sluggo]

By Steve Killings suggestion, I'm building a Freedom 15 and stretching it to 16'. I've heard/read that I probably will need to adjust the end stations so the strips are fair running from the stations to the stem moulds. Any advice or tips on how to do this? Would I maybe staple a few full length strips on the moulds and make some pencil marks on the end moulds, then sand the mould edges down. Refit strips and make sure they are running fair?

thanks!

[Fred G]

When I shorten a canoe,I redraw the stem to match. I'd just take the stem mold plan and extend it in the same proportion as the station stretch.

[Rick]

The way I was going to do this in the table of offsets in CanoeCraft was to loft a new end station by stretching the values given in the table... convert them to metric and multiply by the same percentage that the other stations were stretched.

In the Freedom 15 stretch, the plan station could be gridded off, and then the appropriate values measured in metric and multiplied by 16/15... 1.067. The new stretched measurements then plotted on a new grid and a batten used to create the new station plan.

I haven't actually done this and maybe the difference created by simply adding on the additional stretch to the existing end station by moving it out 1.066% would be so small, the above wouldn't be worth doing.... OTOH, I'd want to be sure that the lines were fair, so I'd probably loft the stretched version just to see what the difference would be..

[sluggo]

I guess a guy would just stretch the horizontal coordinate of the lofted points?

Doug

[Glen Smith]

Since you are just modifying the length, I would say you are right.

[Fred G]

I've done it twice to 10/12, and it works fine for shortening.