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Re: S&G: Plate development
By:Hubert Schreier
Date: 12/13/2016, 8:03 pm
In Response To: Re: S&G: Plate development *PIC* (Nick Schade - Guillemot Kayaks)

If you are trying to make a smooth bottom between the keel and the chine, I have a hard time imagining one where the ends of the keel are not ending at the same point as the ends of the chine.

I was not really clear, it was too early in the morning. The flat panel shapes I showed were for the Sea Tour 15 by Tom Yost with no round-over at the keel/stem transition (could not figure out how to import a rounded keel into FreeShip and have the control grid come out correctly). With a small amount of rounding, I can develop this into a reasonable looking panel with no hollow at the keel.

The stems for this design are not near as plumb as, e.g., on the Great Auk or Epic kayaks. For more vertical stems, I found it much more problematic to develop a reasonable panel. As a way around that, I have experimented with an additional "smooth" bottom panel. Like you said, the keel and chine have to end at the same point. To keep the sides more vertical near the ends, I pinch the ends of the bottom panel together in plan view. The bottom panel develops nicely without significant error no matter what I do, as it is practically flat with a change in deadrise of about six or seven degrees along the keel. The next panel above can be a bit more problematic if the ends of the first chine are very fine. But nothing compared to using a single panel that turns 80 degrees.

Given the panel shapes you provided, my first instinct is to take a pair of scissors and cut of the keel edge at the ends as shown below. I think this would make a shape that can develop nicely and probably has nearly the shape you would want.

I have actually thought about doing this in reverse: Develop the panel using a smooth stem transition and then leave extra material to make a plumb stem!


The original developer of FreeShip has created a commercial version DelftShip http://www.delftship.net which also has a free version. You might see if he has any more information with the newer version.

I have looked at DelftShip, but they don't have linux or mac versions available as far as I know, and I don't have a windows computer. I don't really want to use ready-made software for this project anyway, as trying to figure out how to do this myself is part of the fun for me. I just wanted to see if my panel shapes were at least in the right ballpark. Since my last post, I have been able to make a more similar shape to mine in FreeShip by changing the control grid around, so I am fairly confident that my code does what I intended.

Messages In This Thread

S&G: Plate development
Hubert Schreier -- 12/3/2016, 4:10 pm
Re: S&G: Plate development
upchurchmr -- 12/3/2016, 4:38 pm
Re: S&G: Plate development
Hubert Schreier -- 12/3/2016, 4:55 pm
Re: S&G: Plate development
upchurchmr -- 12/3/2016, 5:45 pm
Re: S&G: Plate development
Nick Schade - Guillemot Kayaks -- 12/3/2016, 10:14 pm
Re: S&G: Plate development
Hubert Schreier -- 12/4/2016, 12:57 am
Re: S&G: Plate development
upchurchmr -- 12/4/2016, 3:37 am
Re: S&G: Plate development
Hubert Schreier -- 12/4/2016, 11:45 pm
Re: S&G: Plate development
Alex Ferguson -- 12/5/2016, 3:38 pm
Re: S&G: Plate development
upchurchmr -- 12/5/2016, 5:42 pm
Re: S&G: Plate development
Hubert Schreier -- 12/5/2016, 9:23 pm
Re: S&G: Plate development
Alex Ferguson -- 12/5/2016, 9:55 pm
Re: S&G: Plate development
Hubert Schreier -- 12/6/2016, 12:34 am
Re: S&G: Plate development
Nick Schade - Guillemot Kayaks -- 12/4/2016, 8:20 am
Re: S&G: Plate development *PIC*
Hubert Schreier -- 12/5/2016, 10:23 pm
Re: S&G: Plate development
Bill Hamm -- 12/6/2016, 12:56 am
Re: S&G: Plate development
Hubert Schreier -- 12/6/2016, 1:03 am
Re: S&G: Plate development
Bill Hamm -- 12/6/2016, 1:09 am
Re: S&G: Plate development
Hubert Schreier -- 12/6/2016, 1:20 am
Re: S&G: Plate development
Mike Bielski -- 12/6/2016, 1:09 pm
Re: S&G: Plate development *PIC*
Hubert Schreier -- 12/6/2016, 3:07 pm
Re: S&G: Plate development
Mike Bielski -- 12/6/2016, 4:35 pm
Re: S&G: Plate development
upchurchmr -- 12/6/2016, 7:14 am
Re: S&G: Plate development
Hubert Schreier -- 12/6/2016, 8:45 am
Re: S&G: Plate development
Nick Schade - Guillemot Kayaks -- 12/6/2016, 8:49 am
Re: S&G: Plate development
Hubert Schreier -- 12/6/2016, 10:04 am
Re: S&G: Plate development
upchurchmr -- 12/6/2016, 11:04 am
Re: S&G: Plate development *PIC*
Nick Schade - Guillemot Kayaks -- 12/6/2016, 7:29 pm
Re: S&G: Plate development
Hubert Schreier -- 12/6/2016, 8:26 pm
Re: S&G: Plate development *PIC*
Hubert Schreier -- 12/7/2016, 12:27 am
Re: S&G: Plate development
Nick Schade - Guillemot Kayaks -- 12/7/2016, 7:45 am
Re: S&G: Plate development
upchurchmr -- 12/7/2016, 9:29 am
Re: S&G: Plate development
Nick Schade - Guillemot Kayaks -- 12/7/2016, 10:21 am
Re: S&G: Plate development
upchurchmr -- 12/7/2016, 12:43 pm
Re: S&G: Plate development *PIC*
Hubert Schreier -- 12/13/2016, 4:00 am
Re: S&G: Plate development *PIC*
Nick Schade - Guillemot Kayaks -- 12/13/2016, 6:54 pm
Re: S&G: Plate development
Hubert Schreier -- 12/13/2016, 8:03 pm
Re: S&G: Plate development *PIC*
Nick Schade - Guillemot Kayaks -- 12/13/2016, 11:10 pm
Re: S&G: Plate development
Hubert Schreier -- 12/30/2016, 6:08 pm
Re: S&G: Plate development *PIC*
Dan Caouette (CSCWC) -- 12/14/2016, 6:55 am
Delftship
Nick Schade - Guillemot Kayaks -- 12/14/2016, 8:50 am
Re: Delftship *PIC*
Dan Caouette (CSCWC) -- 12/14/2016, 11:57 am
Re: Delftship
Nick Schade - Guillemot Kayaks -- 1/25/2017, 9:41 am
Re: Delftship
Dan Caouette (CSCWC) -- 1/25/2017, 6:19 pm
Re: S&G: Plate development
Hubert Schreier -- 12/30/2016, 5:53 pm
Re: S&G: Plate development
Dan Caouette (CSCWC) -- 12/31/2016, 8:57 am
Find "MultiConic Dev of Hull Surfaces"
mick allen -- 12/5/2016, 8:16 pm
Re: Find "MultiConic Dev of Hull Surfaces"
Hubert Schreier -- 12/5/2016, 11:07 pm