loft twist even with vertex matching

jim_wilson436

I have matched the vertex counts of the end faces and matched two vertices, but the loft is still twisted. The twist is most obvious in the bottom view).

https://cad.onshape.com/documents/70d966de3badcd4297a0364f/w/f881c41642a17ab1e8adf1a4/e/6f0b58722b7a9ad808859279

What did I do wrong? I reviewed several loft-twist questions posted previously in this forum, and double-checked the conditions that helped those users, but I must be missing something different from them.

Is there a better way to construct this kind of part?

NeilCooke

It's not enough to add points to a sketch, you have to use the split tool (in sketch) to make it into multiple segments. You can also use Shell to get your thickness and extrude/remove to get the cutout:
https://cad.onshape.com/documents/e2d94d41efc62d3076762e40/w/42f5e364af3a4792091b1313/e/d89eb3bb91ea0150d4aee2ae

steve_shubin

@jim_wilson436

Step through the features list, and review the settings of each feature within that features list to see how this bottle was made

Of the 4 S shaped splines, I only sketched one of those four, then I mirrored it within the same sketch. Then I mirrored that sketch using the feature mirro

This method of lofting is different in that it does not rely on split but rather relies on guides

https://cad.onshape.com/documents/cdd6b14191f88c318b455902/w/4e1f48a392c035e031f4dd32/e/388c550ca98d2bb2f08fb7e3

jim_wilson436

Thank you, Neil and Steve!

Neil's solution hit at the crux of my error -- I didn't realize the matching vertices needed to be segment endpoints, but that does make sense. Also, thank you for introducing the shell feature. I was unaware of that tool, and it will surely be quite useful in the future as well.

Also, kudos to Steve for an alternative approach to making the part.

Cheers!

Jim

NeilCooke

It's not enough to add points to a sketch, you have to use the split tool (in sketch) to make it into multiple segments. You can also use Shell to get your thickness and extrude/remove to get the cutout:
https://cad.onshape.com/documents/e2d94d41efc62d3076762e40/w/42f5e364af3a4792091b1313/e/d89eb3bb91ea0150d4aee2ae

steve_shubin

@jim_wilson436

Step through the features list, and review the settings of each feature within that features list to see how this bottle was made

Of the 4 S shaped splines, I only sketched one of those four, then I mirrored it within the same sketch. Then I mirrored that sketch using the feature mirro

This method of lofting is different in that it does not rely on split but rather relies on guides

https://cad.onshape.com/documents/cdd6b14191f88c318b455902/w/4e1f48a392c035e031f4dd32/e/388c550ca98d2bb2f08fb7e3

jim_wilson436

Thank you, Neil and Steve!

Neil's solution hit at the crux of my error -- I didn't realize the matching vertices needed to be segment endpoints, but that does make sense. Also, thank you for introducing the shell feature. I was unaware of that tool, and it will surely be quite useful in the future as well.

Also, kudos to Steve for an alternative approach to making the part.

Cheers!

Jim

jim_wilson436

Uh, that was dumb of me. How do I get rid of "Accepted answer" on my own post. LOL

NeilCooke

jim_wilson436 said:

Uh, that was dumb of me. How do I get rid of "Accepted answer" on my own post. LOL

That's fine - it was a great answer!