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Re: Strip: great auk end forms
By:Ian Johnson
Date: 1/23/2017, 4:03 am
In Response To: Re: Strip: great auk end forms (Lynn Markle)

Keeping in mind that, I'll surmise, the author added this section of the book with a healthy dose of 'try it at own risk', I'd say he meant you might need to scale the end forms lengthwise only. To do this properly, I'd expect you would need to apply the same principle with the formula, so that the result is that the extreme ends squish inwards more than at the inside end of the form.

Think of it as a series of vertical lines (the Length column), on which you will plot the deck and hull markings to then draw a fair curve through each. In the table, the Length lines are neatly spaced at 1". In your reduced length of 14', you will need to shrink the gap between these - but not by the same amount each. In the same way that you squeeze the forms closer together by more as you get to each end, you need to continue this principle with the end forms. So the distance between lines 0 and 1 will be as near as doesn't matter to an inch, and then the distance to each line reduces progressively.

The issue you face is making sure the line along the end forms is fair AND is fair with the deck and hull.

Like your son, I wanted to build the Guillemot from the table - there was something amazing about turning two planks of wood and a table of numbers into a real boat. I really enjoyed the plotting part, but you're biting off quite a lot by changing them. Very, very easy to introduce an error that won't obvious until you stand flummoxed trying to figure out why the last few strips won't neatly follow the forms, because of a small error in form placement. It's not very easy to fix errors at that point without starting over! But I'd give it a go.

Something that might help is to plot the side profile on the floor, full size (at your 14' length). That is, plot each form's height and depth, and place your end forms. Then bend a strip along them all and make sure the end forms follow the fair curve.

Note don't take what I have written *too* seriously - I've only built one, and I can only refer to my now very heavily thumbed copy of Nick's book. So take others' advice over mine if it is contradictory!

Good luck!

Ian

Messages In This Thread

Strip: great auk end forms
Lynn Markle -- 1/13/2017, 9:08 pm
Re: Strip: great auk end forms
Marc Upchurch -- 1/14/2017, 12:57 am
Re: Strip: great auk end forms
Lynn Markle -- 1/15/2017, 5:46 pm
Re: Strip: great auk end forms
Marc Upchurch -- 1/15/2017, 6:38 pm
Re: Strip: great auk end forms
Etienne Muller -- 1/16/2017, 5:05 am
Re: Strip: great auk end forms
Ian Johnson -- 1/23/2017, 4:03 am
Re: Strip: great auk end forms
Mark N -- 1/14/2017, 11:11 am
Re: Strip: great auk end forms
Lynn Markle -- 1/15/2017, 5:18 pm
Re: Strip: great auk end forms
Bill Hamm -- 1/17/2017, 1:00 am
Re: Strip: great auk end forms
Les Cheeseman -- 1/29/2017, 10:55 am