Intriguing "problem" with FREEship

Hi,

I've started to design a hull in FREEship and encountered a rather interesting problem. I altered some of the points at the stern of the hull, to make the sides of the hull at the top more vertical. tWhen I went to run the Design Hydrostatic calculations on it, it returned that the hull was not submerged!! This slightly defies the laws of physics IMHO. Why is this? User error or bug? Interestingly, some of the figures that move dynamically as you move points around disappear when this happens, too. It seems it doesn't like have the rear of the hull as level. The file is available on request.

Screenshots attached.





Best regards,
Robin.

 

Check where your waterline is relative to those points, and make sure there's no opening between stern and centreline (ie, all points on centreline have y=0). If a leak point drops below the waterline, it's impossible to compute hydrostatics data.

 

I encountered same Prob, Marsh
mind you I ALWAYS have problems
latest is trying delete control points in Rhino, highlight, press delete, nothing happens
You know I could have built a boat whilst I fiddle with CAD

 

Hi,

(I'm sure I already replied to this thread a minute ago???)

Thanks for mentioning about checking the points relative to the waterline! If you look at the stern of the hull (closest to you in the perspective view) you can see that the open end of the hull is below the water line. How do I close this off??

Best regards,
Robin.

 

See
http://boatdesign.net/forums/showthread.php?t=12769

 

Make a transom. To do so: Ctrl + click on the aft edge of the hull. Edge > Extrude. Extrude it either vertically or transversely, then set the coordinates of the new points to where you want them. Often if I want a flat transom, I will collapse all its interior edges and points, so that it's not curved.

 

So could I.... but for me at least, fiddling with CAD is free, while building a bigger boat would cost thousands. And the university keeps taking my thousands. Grr. Ah well, can always dream....
Working on a 12.5m cat of my own right now. 10 t disp, target is 20+ kts with 180 hp. Might actually build something like it in another 10 years, when I have a real job....

 

well I could give you a REAL job
I,m thoriughly sick of this, Id pay you to do it, not a lot but?

 

Hang in there lazeyjack! It will start making sense soon.

 

ok mate thanks for farm stuff, sorry have not written will call, get bogged down