projected sketch problem 1

[rollinhultz]

I used split line to project a sketch onto a cylinder and it worked fine to a point. I can select a face inside or outsid the sketch but I cannot use the sketch for an extrude boss. I projected the sketch for that purpose and when I am trying to extrude it will not allow me to select the face or sketch. Solidworks help and tutorials were not specific to this area.

 

[Updraft]

It sounds like you are trying to use the projected sketch, which is now a 3D sketch, to create a feature. Your sketch must be on a plane, not a non-planar surface.

You don't indicate exactly what you are trying to do, but perhaps you can create your sketch on a plane outside the cylinder and extrude up to the surface of the cylinder. If you want the feature to be offset from the surface you can then trim it to a surface that is offset from the cylinder. Better yet would be to offset the surface before creating the feature, then extrude the feature to the surface of the cylinder but extrude it FROM Surface/Face/Plane and select the offset surface. You'll then want to hide the body of the offset surface.

- - -Updraft

 

[rollinhultz]

Thanks for the tips I'll see if any are applicable. I usually don't come accross any modeling problems I can't quickly figure out.
To be more specific about the problem I created a muffle tube cylinder closed both ends and I have a rounded square tube perpendicular with a flange for header connection sticking out of it. I decided after the fact to reinforce the tube to header connecton by creating a face flange on the muffler pipe surrounding the header tube and conforming to the shape of the pipe, hence my 3d projected sketch around the header tube and on the pipe face. I will try the extrude from face deal with the sketch I used to create the projected sketch. I'll let you know how it works out.
The problem is the mufflers (being made by a well known company) are breaking at the header tube due to the thinness of the Stainless tubing at the joint where the tubing meets the header tube. They are CNC welded and look good but the small engines have a lot of vibration I felt I might reinforce the muffler tubing with a high temp soldering of a flange that conforms to the pipe and gives the header tube something more significant to be pre-welded to