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Re: CX25 Questions for Jacques

Posted: Wed Feb 06, 2019 3:42 pm
by Bhill
Jacques,

I am currently in the middle of building my practice boat to get ready to do the scaled CS25 and just wanted to say some full on CS28 plans would be awesome!

Re: CX25 Questions for Jacques

Posted: Thu Feb 07, 2019 10:52 am
by jacquesmm
I keep thinking about that but I am in the middle of redesigning some of my old plans including some for foam sandwich.
I was stuck for 2 weeks just updating software which required a new computer, 3 new programs and changing the attributes of all my existing files!
I am almost there with the update of the XF22 which is also a scaled up boat.

Re: CX25 Questions for Jacques

Posted: Mon Feb 25, 2019 10:36 am
by hbav984
from my finding.....

Scaling the CS25 10% and Stretching by a foot is easy on paper.... the draw backs are as follows:

1-Much more material
2-the scantling spacing needs to be adjusted to accommodate the larger size (Should have a Naval architect do this)
3-Stringer thickness should be increased to a min of 1.5"
4-Need another layer of 12 oz 50" glass all around inside and out
5-Use 12" Biaxial tape where it calls for 6" tape
6-transom thickness need to be a min of 3"

Good luck!!!!!

Re: CX25 Questions for Jacques

Posted: Mon Feb 25, 2019 12:22 pm
by jacquesmm
Did you see this:
http://bateau2.com/howto/scaling.php

I wrote that a couple years ago.

hbav984 wrote: Mon Feb 25, 2019 10:36 am from my finding.....

Scaling the CS25 10% and Stretching by a foot is easy on paper.... the draw backs are as follows:

1-Much more material
Yes for the plywood, my nesting is all messed up but not much for glass and resin.

2-the scantling spacing needs to be adjusted to accommodate the larger size (Should have a Naval architect do this)
3-Stringer thickness should be increased to a min of 1.5"
4-Need another layer of 12 oz 50" glass all around inside and out
The CS23 and CS25 have the same hull shape but scaled. I designed a 24 and did separate calculations for each. Ideally, the frames/bulkhead spacing should be adjusted = big job. Stringers can be thicker but not really important, it's the glass that counts. I should recalculate all glass, skins and tabbing and will probably end up with one more layer 12 oz. in and out. That's a guess, nothing else than a guess.

5-Use 12" Biaxial tape where it calls for 6" tape
6-transom thickness need to be a min of 3"
Sorry no. The transom thickness is fine and the transom glass goes by the rules for the bottom.
The small tape is just for accommodations and details, not structural.

Re: CX25 Questions for Jacques

Posted: Mon Feb 25, 2019 2:49 pm
by hbav984
Thanks Jacques,

Guess most of money was spent on scantling layout....(BTW-I did offer to pay you to do it).

All the other info he provided like stringer thickness and transom thickness is not really needed but will anyway but the additional layer of glass is a must. I was doing this anyway regardless because i'd rather have the additional strength.

Well,
Now folks will get see a Scaled, Stretched CS25. It's called the CSS28. Carolina Super Sportfisher!!!!