Tapering a revolved surface 1

[ninerocket1]

I need to model up a curved tunnel gate for an injection mold. I am simply revolving a circle about 180 degrees to create sort of half a donut. The problem I have is how to get it to have a 3 degree taper from one end to the other.
Any help would be great.

 

[Xwheelguy]

Taper command won't work?

Do you know the 'unwrapped' length of the gate? If you do, extrude in a straight line with 3 degrees draft & use the start & end diameters to perform a swept free form feature with an arc as your guide string.

Tim Flater
Senior Designer
Enkei America, Inc.

http://www.enkei.com

 

[ninerocket1]

Thanks Tim....I got unigraphics kind of thrown at me without training. I had to mess with the way I picked the sections but got it modeled up this morning.

Jim Walker

 

[Xwheelguy]

Jim,

How did you go about getting it to work?

Tim Flater
Senior Designer
Enkei America, Inc.

http://www.enkei.com

 

[ninerocket1]

Tim,
I did know approximately how long the pull would be,
So I did as you suggested and drew an arc the radius I wanted , put the center of the 2 diameters at the end points of the arc. Rotated the arcs so I could use the swept
command. Almost left something out, when I first attempted this (using complete circles) the computer would twist the shape (going to a thin section in the center of the body.
I had to split the circle into 2 arcs and pick the 2 arcs for my section, (1st and 2nd)this gave me a very usable body well within the tolerance I had. Just had to be sure that I pick the sections either both outside the string or both on the inside. Hope this explains my procedure so you can understand.

Thanks Again....Jim Walker

 

[Xwheelguy]

Yes, I understand.

You have to have 2 section strings (circles) & 1 guide string (an arc that defines the sweep path). I played around with it a bit today & got it to work out. I ended up having to force the alignment relative to an axis that came through the center of the arc that I used as a guide. You also have to be careful where you select the 2 circles (if you're sweeping a full 180 degress), as that can cause twisting as well. If I remember correctly, the red vector arrows had to point in opposite directions.

Tim Flater
Senior Designer
Enkei America, Inc.

http://www.enkei.com