IJN Tone (formerly Something Silly)

https://help.autodesk.com/view/fusion360/ENU/?guid=GUID-2CECE70A-7FD8-42CF-91C9-9A53B087BF96

I use the draft analysis tool in the cad package I use. You should see if the link above gets you the same result

 

What Kotori says... that is also what I do... I set the density to 1kg/m^3 and then slice it at the waterline... check the weight, which verifies that the hull is close enough.... then change the slice till I match the target weight.... and there is the waterline. Generally it will predict it a skosh higher due to the balsa sheeting, but it will be close enough

 

Just be careful in areas of strong curvature, as your approach will only be absolutely correct for regions of the surface where the surface normal is perpendicular to the axis of rotation for the 45 degree transformed plane . the answer you get will be close (generally) except at the bow and stern for most ships...

for reference, the same image as before with red = 45 or more, using your approach. No substantial differences in areas that matter, but if you had a stumpy one (like a monitor) it would lie more.

 

there isn't one. That limitation has been in autodesk products for ages, and it exists only because some programmer somewhere said" hey no one drafts more than 15 degrees anyways, set the limit here"

Practically, since the bow and stern are solid, you will be within the tolerance of model boats except on hulls which bulge out a lot like the monitors. in that case, do a 45 degree plane around the plane formed by the surface normals. Can't really describe it without a diagram. How I used to do this long ago check was to take an intersection curve at the angle that I am most interested in, and check there with a tangent line set 45 off the horizontal and tangent to the surface.

 

and preliminary rib layout is complete. Time to lay out internals... then carve away excess mass of plastic/add mount points and water chaneling.

 

progress on B turret.

 

I am trying something different. The propulsion/rudder components are their own module... whether it is removable or permanently installed after assembly is TBD, but since I have to split the hull up for printing anyways, it doesn't really matter if I split it up in a manner that lets met get the propulsion and steering components fully assembled and tested while the rest of the hull design and print work progresses. First print showed some design errors / tolerance issues, second had a warping issue when I tried to print all three parts at the same time... Second print is probably usable but I will try for a third...

 

The print is starting stern to bow now. That will let me get the mechanicals done and then work on some of the design work while the stern is printing. Unfortunately I ran out of all of my bright colors bought for my girls so back to grey

 

It is an experiment and frankly not a bad hull to do the experiment with. We will see how it turns out.

 

Slowly it grows

 

3.5 lbs at this stage

 

Well the gearbox works... May make a few tweaks to it for ease of access

 

and an update. Shielding is in, cannon is designed and built, ready for test firing. This is the 4th of them.... Third fired fine but was a pain to print .... Propulsion module worked out well enough. Need to make some drag disks and mount dummy shafts.