problem to chamfer a sweep/extrude profile

[cvelasquez1]

Can somebody help me with this problem? I have been trying to make a chamfer in a pipe fitting, but everytime shows an error in apply the feature. I have changed the distances in anyway and not luck. In fact, I apply a fillet and this feature works perfect. With solid primitives work well, but when i try to make a primitive with a patch like sweep/extrude it seen not working when i try the chamferedge command. What am I doing wrong? I left a link to my youtube with the video showing the problem. Thanks.

https://www.youtube.com/watch?v=wB7avrXRmhI&feature=youtu.be

I'll appreciate your help.

Carlos Velasquez.

[nestly2]

I think you'd have to Chamfer by angle because the inside and outside distances are not consistent due to the curvature, unfortunately I've never been able to get an angled chamfer to work properly on a 3D object. 

Perhaps use a surface representing the chamfer to SLICE the solid.

http://www.youtube.com/watch?v=gtUpuzIXsBc

[cvelasquez1]

Thanks nestly2 for you answer, I performed your advice making a surface and then slice it, but I'm still asking something. Really, I wanna perform a chamfer .25 x .25 distances. I can do it in a primitive solid with desire result. Chamfer .25 one distance, .25 another distance and .3536 aligned distance. When I perform the method that you show me the result is not exact at all. The aligned distance is .3522 in case is doing with making a horizontal line purple (.25), it doesn't follow the vertex line that form the arc in the pipe. If I make the horizontal line totally straight with ortho mode on, the result still imprecise it happen also if I use arc line. I can make this exercise easy with just taking off two decimal at the precision in the units tab, but what about if I wanna keep a precision of four decimal? how can I fix it?  

I attached two images showing that.

Capture 1: Right side a solid with the chamfer desire, left side chamfer applied with method straight line. Purple dimension is the correct dimension that supposed to have (only is shown for reference with the purple lines). White dimension chamfer made with straight line and the slice it. No exact.

Capture 2: Right side show a gap between the straight purple line and the vertex line. Note the intersection between the chamfer made and the purple line that is no exact, the purple line is a little big long (exact dimension) than the result. look the dimensions white. it still imprecise. I used a arc line to make this example.
Note: Purple lines are for showing purpose only

Thanks.

Carlos Velasquez

[nestly2 · Accepted solution]

I do not believe it is possible to maintain a 0.25 x 0.25 chamfer on that geometry because the inside radius is smaller than that outside, therefore both the chamfer angle and the aligned length of the chamfer would vary around the circumference.   Using a revolved surface to slice the bevel accurately represents the way real butt weld elbows are manufactured, however I do realize doing it that way doesn't necessarily produce the best result in a detail view.

Perhaps the way to achieve the result you're seeking is to reduce the radius of the elbow by 0.25 and then add a straight segment at each end of the arc to bring the face to face dimension back to 1.5x dia.  Doing so will result in 0.25 long "cylinder" at each end of the elbow that will Chamfer nicely.  I kinda did the video below in a hurry, but hopefully it's still clear enough to follow.

https://www.youtube.com/watch?v=ludcHf2QTRM

[cvelasquez1]

Thanks nestly2, it works perfect. I appreciated your help.