cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
Showing results for 
Search instead for 
Did you mean: 

Community Tip - New to the community? Learn how to post a question and get help from PTC and industry experts! X

Drafting a cylinder end

ptc-593619
1-Visitor

Drafting a cylinder end

Pro Modelers,
When drafting the end of a cylinder, I usually choose the edge as my draft hinge. Pro then picks the end of the edge as the draft point and invariably this is not the point I want, I suppose this is because Pro looks at a cylinder as two semicircles extruded. Short of putting in a tangential plane every time, is there any way to force the draft point to the middle of the edge?

Your help is always appreciated,

Richard A. Black
tel: 269 781-0539
-
http://www.automotive.eaton.com


1 REPLY 1

Hi Richard,
The draft method you describe will not give you a flat draft surface so
unless this is your intention to have a curved surface you want to use
neutral plane instead. I have made three pictures part way through the
draft feature that show what I mean. Hopefully they will come through
the size limit.

draft_use_edge_15.jpg
Shows the method I think you are describing. The top semi circle of the
cylinder stays unchanged and a curved draft surface drafts away from the
original face using the central datum as the pivot direction (you could
also use something like a default coordinate system for this).
Sometimes it is important for an edge to remain true in which case then
use this method. The draft in the picture does not show up so clearly
but you can see that it follows the top semi circle and gets darker as
it gets to the far side indicating that the surface has gone behind itself.

draft_neut_plane_ctr_15.jpg
Drafts the same end cylinder surface but uses the central plane (though
the ends of the semicircles) as the neutral plane and draft direction.
This gives a flat drafted surface. Probably the most used method as it
allows non connected surfaces to be drafted using the same neutral plane

draft_neut_plane_top_edge_15.jpg
Drafts the same end cylinder surface but uses a top datum plane made
tangent to the cylinder as the neutral plane and draft direction. This
gives a flat drafted surface.

Depending on your construction both of the last two methods may require
a constructed plane if there is not one already available to use.

Hope this helps.

Regards, Brent Drysdale

Mechanical Designer

Tait Electronics Ltd (www.taitworld.com)

New Zealand

Ph. +64 3 358 1093



- wrote:
>
> Pro Modelers,
> When drafting the end of a cylinder, I usually choose the edge as my
> draft hinge. Pro then picks the end of the edge as the draft point and
> invariably this is not the point I want, I suppose this is because Pro
> looks at a cylinder as two semicircles extruded. Short of putting in a
> tangential plane every time, is there any way to force the draft point
> to the middle of the edge?
>
> Your help is always appreciated,
>
> Richard A. Black
> tel: 269 781-0539
> -
> http://www.automotive.eaton.com
>
>
>
> ---
>
> You are currently subscribed to model.
> To unsubscribe send a blank e-mail to
> -.
>
> For assistance, email us at - or find other
> contacts at www.ptcuser.org/org/contacts.html.
>
> PTC/USER and the PTC/USER logo are registered trademarks of PTC/USER,
> Inc.
> Pro/ENGINEER is a registered trademark of PTC.
>
> Message authors are solely responsible for the content of their posts.

Announcements
Business Continuity with Creo: Learn more about it here.

Top Tags