Welcome to the Onshape forum! Ask questions and join in the discussions about everything Onshape.
First time visiting? Here are some places to start:- Looking for a certain topic? Check out the categories filter or use Search (upper right).
- Need support? Ask a question to our Community Support category.
- Please submit support tickets for bugs but you can request improvements in the Product Feedback category.
- Be respectful, on topic and if you see a problem, Flag it.
If you would like to contact our Community Manager personally, feel free to send a private message or an email.
Loft guideline trouble
mike_hölscher
Member Posts: 109 PRO
Hey,
We have a legacy SW part that needs to be revised. I started to remodel in Onshape but found some lofting trouble.
The end result should look like this.
Where the big curved inside should really be cylindrical, and transition nicely into the straight side flaps.
The curved outer rim is bigger in the middle than on the sides, so also should be lofted.
In SW, when lofting in between two profiles and adding a single guideline, makes THE ENTIRE loft bend exactly over that guide curve.
In Onshape, when lofting in between profiles and adding a singe guideline, only makes THAT SINGLE line of the loft bend over the guide curve, and the rest kind of does something in between following this line and shortest path.
Screenshots below to illustrate:
First the SW Loft Feature where you can see the entire loft follows the single guide curve very nicely.
Second the Onshape Loft Feature where you can see the guide curve vertex of the loft follows the guide curve, but rest of the loft does not.
Adding more guide curves does not help, except if you would (be able) to do it for every vertex on the profile.
Using Path looks nice at first, but still does not create a real cylindrical face on the inside of the loft, and does not work well with Normal to Profile, which is needed to get a smooth transition after mirroring.
Is this something we can solve?
We have a legacy SW part that needs to be revised. I started to remodel in Onshape but found some lofting trouble.
The end result should look like this.
Where the big curved inside should really be cylindrical, and transition nicely into the straight side flaps.
The curved outer rim is bigger in the middle than on the sides, so also should be lofted.
In SW, when lofting in between two profiles and adding a single guideline, makes THE ENTIRE loft bend exactly over that guide curve.
In Onshape, when lofting in between profiles and adding a singe guideline, only makes THAT SINGLE line of the loft bend over the guide curve, and the rest kind of does something in between following this line and shortest path.
Screenshots below to illustrate:
First the SW Loft Feature where you can see the entire loft follows the single guide curve very nicely.
Second the Onshape Loft Feature where you can see the guide curve vertex of the loft follows the guide curve, but rest of the loft does not.
Adding more guide curves does not help, except if you would (be able) to do it for every vertex on the profile.
Using Path looks nice at first, but still does not create a real cylindrical face on the inside of the loft, and does not work well with Normal to Profile, which is needed to get a smooth transition after mirroring.
Is this something we can solve?
Tagged:
0
Best Answer
-
philip_thomas
Member, Moderator, Onshape Employees, Developers Posts: 1,381 
Mike - great question.
Yes this part can be modelled
If you want to see how, please post a public link and 5 guys will fall over themselves to show you how.
Philip Thomas - Onshape5
Answers
Yes this part can be modelled
If you want to see how, please post a public link and 5 guys will fall over themselves to show you how.
After half a day experimenting I think I have found a reasonable way of modeling something quite similar. But it involves sheet metal to create a nicely cylindrical shape that needs to be cut in flattened state to have nice edges to attach the curved outer rim using a loft with guidelines.
https://cad.onshape.com/documents/aa7bd98fd8cf04d2fc659afd/w/060fc5071dc3e390ac319981/e/96e904762a7da114fab3aac0
If someone knows a better/cleaner way. Let me know.
P.S. Are you deciding which answers are 'Accepted Answers' nowadays? I did not accept anything.
projektowanieproduktow.wordpress.com