first question hull curve

In the case of this particular boat the panels are "developed" and typical of "sheet goods" types of builds, like that used in metals (like above) or plywood. The description is pretty difficult to put into a few paragraphs, so no there isn't a "quick explanation" for this type of panel creation.

The shapes employed have to serve several functions, one of which is the material has to be able to conform to it. You can stretch aluminum and steel panels, though this is seldom done on a hull shape like this, so the panels are actually made from cylindrical or conical sections. The above side panels appear to be cylindrical and this would be common for this type of hull.
The hand calculations for developed hull panels can be daunting, software has relieved much of this, but the other portions of shape selection have to be addressed, such as volume distribution for the anticipated or specified SOR.

Again it would be helpful if the original poster tells us what he's trying to do. If it's a question of drawing the panels in software, this is one thing. If it's a question of trying to make the panels on a shop floor, as you're bending plate, this is an entirely different animal. This portion of the thread isn't clear.

If trying to make a full size panel, there are a number of techniques (some mentioned above). If it's a software question, there are countless thread here and elsewhere, that will help as well. Without clarification, this thread is going to die.

 

hmm

thanks for all the replies im not using software im simply drawing the shape of the front of the hull on a sheet of aluminum on the shop floor i don't know how else to explain it any different

 

This is what I thought. To get a curve, use a batten, which is a light weight piece of wood or plastic or metal, usually square in dimension. You can bend this to a curve, weight it down with some beer cans (unopened) and draw a curve. Then you can make a template of this, which can be flipped over for the other side.

You can also use a "goggle stick" who's techniques is a whole lot easier to show then attempt to describe. Some guys, working in metal like to use round bar stock and just bend it to shape. I've used welding rod, round bar, whatever is handy. Once you have one side, you can flip it or use a plumb bob and lots of tick marks.

If I understand you properly, you have a bottom panel that you want to bend up towards the bow and taper inward on the sides a bit. It would be nice if the side panel landed on it with no gaps so you could just lay a bead. Right?

Using a batten (1/8" square aluminum stock works good for this, though steel and wood are much more reliable) spring a curve that looks about like what you want lock it down (the beer cans thing), then mark the bottom panel, cut to the line. Decide how much you want to bend the bottom and go ahead and bend it. Push the sides in until they touch around the curve, then trace this line. Let the side panel spring open, and cut to the line. Push it back in and check your fits, trim as needed and the block into position for welding.

This is one way, which admittedly is a little "free form" but for this type of boat, just fine, it will not drown you because you guessed at the curve. There are other ways too, several that I can think of.

 

Umahunter,
In my line of work when I need a large scale curve I simply take a square and hot glue straight scraps of wood to it that are long enough to create the curve within them. Then scribe a centerline and a 90 degree line where you want the curve to begin on the work. mark the sticks where you want the curve to begin and end and then drill holes at the appropriate angle through the sticks. slide a pc of spring wire through the holes and hot glue them in place when you have it right.

 

hmm

thanks guys i kinda had the idea to use something bendable to layout the curves along with the tick marks im sure i can get it done. i was gonna have it cut on a cnc table but since my sheet is wider then the biggest table in town its gonna be the hand route. just good to check with those in the know to make sure im not skipping something

 

Send a straight grain piece of knot free wood (doesn't matter what type) through a table saw, set at 1/2". Rip it down until you have a1/2" square piece, that's longer then your curve. This will make nice sweeping curves and you can use weights to hold it in place, as you draw it on the stock. It the wood is too stiff to make the curve you want, cut it down to 3/8" square and try again.

This is the easiest way. Once you got a line you like, make a template of it on paper, cut it out, then flip it for the opposite side.