This is a swept blend to point tangent to "rim" and smooth at top. To get the best surface, the sharp points needed to be excluded. A more controlled version could be made with a revolve. If you are looking to loft it to the outer edges, the result will be much "dirtier" with the varying perimeter and sharp points.
Hey John. I'd try this approach, it gives you curvature continuous (instead of merely tangent) to the flat outer rim, AND it gives you drag handles in the boundary blend to adjust your tangency to the rim and to the datum plane at the top. If it has to be a defined radius, then this wouldn't work. BUT, for that you could revolve the top and connect them with a boundary blend and then adjust the curvature as needed. I've included both models and the image is from the -01 model with the entire dome as a B/B and not the defined radius. Have fun!
Since I tried it, might as well share this approach:
1) basic shape
2) old-school radius dome feature:
3) edges need to be flat, so overbuild
4) add variable-section Sweep:
Sweep is surface with a cross section that of a single spline, with curvature on the dome side and tangency on the end of the flat ledge side:
5) Solidified result:
5) Reflection analysis:
Yes, I post the model here. I also included a similar variable sweep based model where the radius dome was replaced by a simple revolve:
Basic idea is to use the 2-rail sweep instead of boundary blend - to make the blend surface...
Also, the style feature:
is probably the best tool PTC offers for this job - it has the capability to generate G3 continuous surfaces.
Hi, John. I created this part using your iges file. I attached here for your reference see if this gives what you wanted to achieve.
Hey Paul! I took your .igs file and played with it a bit. From what you did, there's a couple things you can try. It's kind of hard to reverse-engineer something without knowing what it's SUPPOSED to look like (i,e, is the CAD model actually what is REALLY desired, or just someone's stab at it?). So, I did it one way in the -04 model (as if you swept a constant arc out of the dome), but then something completely different in the -05 model (pictured in green - my fave) that ended up pretty smooth but a little different towards the bottom. Yours in is grey in the upper right Anyways, this was a kinda fun diversion, thanks!
Tried something else, like this the best, it drives any small distortion into the smallest areas.
It can be done in Sheetmetal using Punch Form. You can control the dome by radius or height.
If you want a solid model not Sheetmetal one, you can use the Sheetmetal part to cut the solid.
Sheetmetal Part
Solid model
The model has 20mm rise which I control it thru the die part.
Die part it is a simple revolved part .
