Taper a solid 90deg pipe fitting?

Hi, Graeme;

To create the aforementioned object:
Draw 2d side view. Draw two 180° arcs in the Z plane for the ends. Use
EDGESURF, pick the inner and outer radius and the two arcs. That gives
you half the elbow. Convert that surface to solid with M2S lisp. Mirror
for the other half. If you want hollow section, then create smaller
object as above and subtract.

Regards,

Igor.

 

To form as a 3D solid. Draw a Ployline arc connecting the line representing one opening of the elbow through a line connecting the midpoint of the 2 arcs representing the walls to the midpoint of the other end of the elbow.

Set the UCS so that you are looking into the 2" opening and draw a 2" circle representing the opening.

To create the solid use the EXTRUDE command to extrude the circle along the polyline path using a taper angle. The tricky part was getting the taper angle. I found this by taking the arcsine of 1/2 the spread over the distance along the center of the pipe. .25 / 3.2745 = 0.07634753 asin = 4.37865234. So use the 4.3786... as the taper angle.

If you want a Hollow Solid. Create another solid in the same manner with slightly smaller diameters at the ends along the same path. then use Subtract.

Allen
Hi, Graeme;
To create the aforementioned object:
Draw 2d side view. Draw two 180° arcs in the Z plane for the ends. Use EDGESURF, pick the inner and outer radius and the two arcs. That gives you half the elbow. Convert that surface to solid with M2S lisp. Mirror for the other half. If you want hollow section, then create smaller object as above and subtract.

Regards,

Igor.