Basic surface draft problem

[SW]

I'm trying to draft a simple extruded surface similar to that shown below on the right, but the feature fails. If I cap the surface as shown on the left then it works no problem. Both surfaces use the "TOP" datum plane as the hinge reference. I could just create a revolved feature with an angle dimension, but its not ideal. What is happening here? I'm sure I must be doing something very stupid.

View attachment 3183

I've uploaded the model and would be grateful if anyone would have a look.



2007-02-20_073243_draft_test.prt.zip

Thanks,

Sam

 

[SW]

I've tried to create a second part as shown below and have the same problem. I've succesfully drafted the upper cylindrical surface, but the feature fails when I try and apply a draft to the lower cylindrical surface. Once again, I could just sketch an angle on the curve, but this I've got a more complex model where this isn't so simple.

View attachment 3184
The model is here: 2007-02-20_084516_draft_test_2.prt.zip

Any help would be appreciated.

Sam

 

[mcgowanp]

You can't draft an open surface. Like you say in you post above, when you capped it the feature created successfully. The surface would need to be merged together.

 

[SW]

The original surface was created with a single revolved surface and is open at one side as shown below.

View attachment 3191
Does this mean that you can't draft
surfaces that have a free edge? I've tried adding an extra line to the revolve in
order to close this end surface, and indeed, the draft then works fine. But
then I need to trim away this unwanted surface, hardly efficient modelling
technique. Isn't this a bit ridiculous?





I'm just going to model the draft in the
original revolve feature, but what has happened to Pro/Engineers power and
adaptability?



Thanks for the help,



Sam
Edited by: SW

 

[mcgowanp]

Yeah I agree. I mean I would have thought that it might have a problem with this as there is not "terminating surface" and so no surface that Proe can defo say this is where the blend stops and so can trim the drafted surfaces and give reliable results,that's what I imagine is going on, but you should be able to do it on an open surface like you say. Just one of many little problems that comestandard. But all CAD systems have these little problems, you cant keep all the people happy all the time!!


Paddy
Edited by: mcgowanp