Re:hull thickness deduction

Re:hull thickness deduction

#33884
otaku
Participant

Hi,

I realize this is a late response, but with respect to the “bulkhead tool”, — if i am correctly understanding the issue here — i use stations to create my bulkheads so that when i export the stations, the geometry is readily used by ViaCAD for thickening in the CAD app.

(Generally, in my DELFTship drawing, i have two fbm.s, one with ONLY stations set for locations of the bulkheads, and the other file with stations set at every single foot (i use feet, not meters, for now) as i do not know just were i will further subdivide the model in my CAD app.)

Here is how i deal with bulkheads:

— create “primary” stations for each known bulkhead location,

— decide whether bhds fwd of amidships have their forward or aft faces ON the station (ie, is the “primary” station coincident to the forward or to the aft face of the bulkhead,

— add a new (thickness side) station either forward or aft of a primary station

As for deck thickness, i suppose do the same for waterlines, but since my decks are at varying elevations (and in some boats, there maybe be curvature, etc.), i just add waterlines for the deck, then thicken those upward or downward depending on what side i assume welding will occur.

In my .dxf file, i break the waterline lines at the bhd boundaries and then i sweep a surface and extrude a thickness.

As for the sideshell surface/solid/thickness, i create a surface between an interval of stations, choosing a spacing that won’t compromise the smoothness of the hull or adversely alter the shape relative to the DELFTship hydros. I don’t want to worsen or adversely improve the hydros. Then, i thicken the surface. Unfortunately for me, thickening dozens of panels of sideshell greatly (relatively) increases the file size. I retain bhd thickness, but use a separate drawing for the thickened sideshell.

It would be nice if DELFTship had these two ideas as features:

— allow insertion of waterlines that can be modified as deck and deck thickness just the insertion of stations can be given closely adjacent stations that act as thickness for use as bulkheads.

— make the hydros report non-modal (meaning the report module’s mode is not preventing the user from manipulating other aspects of the app just because the report happens to be open.

Item two is very important since any minor change of the hull might adversely impact the hydros and stability. Sometimes, i move lines to try to improve the hydros, but the final answer i seek is in the report, not in my eye or hand. So, having to go in and out, in and out, in an out is extraordinarily time consuming, and for the first few months of learning DELFTship, this discouraged me from cleaning up my model. But, because i was exporting crappy lines because i relied on my eye-hand in the absence of automated fairing, i was forced to go back and get better at manually fairing the hull. It was quite time consuming, but i managed to shave off resistance 5,000 pounds hear, 200 there, and eventually i go to 100,000 or so pounds of resistance removed.

But, this brings up a third possible idea for DS Free or DS pro:

– a “fairness indicator” based for use by manual-fairing people

The user could select a set of 2 or 3 waterlines and interactively fair them based on a bar or smoothness curve indicating favorable or bad fairing. This could — like in a spreadsheet — obviate a need to constantly compare numbers.

Marven, this might be “fun” for the tinkerer rather than the “producer”.

Otaku