Helical Swirl

[John.Pryal]

Hi all, i am re-visiting an old problem. I posted on here years ago something similar but stopped researching when I came up with an alternative way of producing the type of suface I was after. Now i am looking for better control. I wonder if anyone could explain the behaviour I am see in this sweep feature. I am trying to create a helical swirl surface controlled by graph. The graph should give me complete control over the path of my swirl surface. I am close but Creo is doing something very weird. If you look at the attached model you will hopefully see the kind of surface i am trying to produce & the crazy way that Creo is dealing with it. Perhaps my graph should look different, perhaps the relation embedded within the sweep feature is not written correctly. Also, could this swirl surface be created by relation only? ie. not using evalgraph.

Best regards

John

[MartinHanak]

Hi,

I guess that the problem is caused by arc flipping caused by sketcher functionality. Unfortunatelly I do not know how to force sketcher to follow the same direction of the arc.

[MartinHanak]

Hi,

do you want to get something like this ?

[John.Pryal]

Hi Martin, no that is not quiet what i am after. Its more of a thin strip. If you look closely at the model i posted you will see what i mean. Thanks for trying.

Best regards

John

[MartinHanak · Accepted solution]

Hi,

... and what about this one ...

[John.Pryal]

Hi Martin, you were very close with that. The surface started off correctly but did not finish correctly. Notice how the surface is normal to the start plane (a 90 degree corner) but is not at the top. With one simple change i did manage to get the surface exactly how i want it. I changed the graph dimension 100 to 75, it should have been 75 all along & it was. I changed it to 100 at some point during my experimentation & forgot to change it back. What i don't understand is how this is working now. I have opened my original model & made the change you have & the feature fails. What am i missing? Have you made some other change I have not noticed. I just discovered that it does not matter which reference you take for x-trajectory either. I attach the model again.  

Best regards

John

[John.Pryal]

This is most bizarre!! I just created a new part following the exact same steps as before & Creo creates the surface no problem. It would appear there was nothing wrong with my approach in the first place. I just went back to my original part & deleted the sweep feature & recreated it. Creo makes the surface no problem. I don't why this happened. I am thinking that there must have been a problem with the sweep section sketch. There was something about that sketch the system did not like. I have redrawn it exactly the same & now it works. Very weird indeed.

Thanks for your time guys.

Best regards

John

[kdirth]

Not sure what you are trying to get to, but looking at your file and trying to filter out the noise, here is my attempt.

[John.Pryal]

Again, not what i am trying to get, but thank you for having a go. The surface i am trying to create turns through 75 degrees while getting bigger in diameter as it climbs 100mm. The surface needs  to start & finish normal to the 2 horizontal datum planes between which it sits. The surface i have managed to create is exactly what i want apart from all the "noise" as you put it. Hopefully, this gives a clearer indication of my requirement.

Best regards

John