Hi, I don't know if this is the right place to ask this question.
I am trying to design this kind of shapes (surfboard fin) and I'm having big troubles with it.
My idea/method was to create the elliptical base then using loft tool but not working.
The point is the top part is way too thin.
How would you design this kind of models?
Thanks a lot
Attach your model and we can help trouble shoot your model. (file\export as .f3d file)
Attached is an approach with a lofted surface. in this case I'm lofting to a point, as in all the profile share a common point. normally not great surfacing practice, but I think good enough for this.
I would do a screen cast, but I don't have a micro phone and I imagine a lot of the details would be hard to get. Here's a start of explaining some of it using screen shots from the example file I sent you. I made sure to capture the timeline and the browser so you could see where we were at in the model-
Sketch 1 is just a three point spline outline of the profile. yo ualways want your splines to have as few points as possible to capture the shape.
a-this line has a constraint to make it perpendicular to the spline tangent handle. that will ensure it is normal to the spline at that point. only was to achieve that condition with fusion's tools. this line is used to define the plane/sketch for the loft profile that runs from the tip to board.
b-defines the plane/sketch location for a spline defining the shape across the width. just seemed like a good spot for it.
c-these extrudes are done in the SURFACE area. these are helper surfaces. I'll use these to set tangent conditions in the loft command and then get rid of them. surfaces are trickier to work with than solids, but offer more possibilities for blending shapes.
d-this flipped the normal side of surface so it was facing the right direction. not a necessary step. command is found under the modify menu.
e-this surface ended up being un-nessesary. I had in mind doing something else when I extruded it.
f-created the pane I referenced in a.
g-the split command (where I stopped the timeline, forgot to label it in pic) created this line on the surface. this breaks the edge into 2 parts so I can use it later in the loft for profiles.
h and i-these are profiles 1 and 3 in the loft command. note i was careful to select the surface EDGES and not the sketch spline. the edge conditions for these are set to be tangent to the helper surface.
(a side note-you can now set loft profile to be tangent to their sketch planes, so the helper surface isn't always needed. I still used one in this case because I needed to split the profile up since fusion still doesn't allow loft profiles and rails to be defined intersection to intersection like other programs. grrr. I could split the spline in the sketch instead, but that an be a mess and makes adjustments that much harder. still need helper surfaces for rails when tang-ency is needed)
j-this is profile 2 in the loft command. it's from sketch6.
k- these are rails 1 and 2 in the loft command. rail1 is in sketch7. note when sketch7 was drawn i projected 3 points in to it and used those to draw the control spline. I projected the 2 endpoints of the construction line in sketch1, and I did a project/intersect of the spline from sketch6.
ok, digest that and come back with more questions.
Will this help, side view 1, top view 2 and front view rail R.
Using Alex's file, adopted to what I was saying.
Don't need sketch 7.
Because we are not using the sketches, for 1 and 2, the option for Tangency becomes available when you use the edge of the grey bodies....
Might help.....
Now I am at this step and don't know how you did the spline from point to the other spline. I tried to do something similar. Then I think there´s another plane with another sketch, am I right?
Then I realized u made the second plane using the helping line after u finish the sketch from the first plane u did.
Then, all these steps kinda messed up in my head and now I really don't understand anything hahaha.
For the first question, I think your missing projecting the points in from the other sketches so you have someware to place the endpoints of the splines. Home work, look up these sketch commands and learn them. the intersection project tool is a necessity when working with lofts. and a gazillion other things.
