Nytrunner
Pop lugs, not drugs
Tangent ogive coming off the airframe, but magic taper to a parabola apex (power series 1/2) or ellipse somewhere in the middle
No, a parabolic (paraboloid of rotation) tip.Trying to imagine this. An ogive with an elliptical tip?
No magic about it. Just pick the change-over such that the slope of the ogive side (circular arc) coming up from the base matches the slope of the parabola coming down from the tip. Freshman calculus or trial and error. With the trial and error method it's easier to keep adjusting the parabolic length until the slopes match; if I want a fixed total length I'll have to find the paper with the formula on it.Tangent ogive coming off the airframe, but magic taper to a parabola apex (power series 1/2) or ellipse somewhere in the middle
Well, I made the pictures last night, put them on a thumb drive, and left it at home. (Shoulda used my phone to transport the files.) Sorry.
Well. I will just keep guessing at it until you post something..
How do you determine where along the length the two curves meet? Mathematically you can place that anywhere along the length then use the tangent constraint to set the diameter, or the other way around.When I tried it in S-works, I just set the parabola apex as the tip with unfixed focal point, put a circular arc tangent to (phantom) body tube with unfixed radius, and used tangent constraint to link them.
That's how I imagine it too.
Interesting, what problems is fusion giving you?
Than looks like you've got about the right idea. I put the change-over about half way along the length.
View attachment 386835
Actually my preference is for nose pyramids. Easy and cheap to make. Given they are paper and easily crushed they are likely safer in the rare event of a ballistic reentry.
When I printed the cone I sanded the printlines out. Also the cones are printed for relatively small tubes
No, a parabolic (paraboloid of rotation) tip.
No magic about it. Just pick the change-over such that the slope of the ogive side (circular arc) coming up from the base matches the slope of the parabola coming down from the tip. Freshman calculus or trial and error. With the trial and error method it's easier to keep adjusting the parabolic length until the slopes match; if I want a fixed total length I'll have to find the paper with the formula on it.
To do it in OpenSCAD I would dig up or recreate the math and write it into the code.I've done some stuff like this with iterative programming - it would be an interesting project in OpenSCAD. Just thinking about it, I think it would run something like this...
(Am I the only person who engages in recreational calculus?)
(Am I the only person who engages in recreational calculus?)
I sometimes wonder the same thing!(Am I the only person who engages in recreational calculus?)
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