Sketching inside a cylinder
Sketching inside a cylinder
(OP)
Hello,
I'm designing a two stroke cylinder. I'm trying to sketch the exhaust port and duct. I'm finding it difficult to sketch the outline of the port onto the cylinder wall and then extrude cut the duct. I have tried a 3D sketch on a plane at both the angle of the duct (20 degress from Horiz) and front plane. However then i try the extrude cut the edges of the port turn up at the surface of the cylinder wall. I want the top of the port flat as in the sketch.
Not sure if i'm going about this the right way.
Using SW 2008 Sp5
Thanks
I'm designing a two stroke cylinder. I'm trying to sketch the exhaust port and duct. I'm finding it difficult to sketch the outline of the port onto the cylinder wall and then extrude cut the duct. I have tried a 3D sketch on a plane at both the angle of the duct (20 degress from Horiz) and front plane. However then i try the extrude cut the edges of the port turn up at the surface of the cylinder wall. I want the top of the port flat as in the sketch.
Not sure if i'm going about this the right way.
Using SW 2008 Sp5
Thanks






RE: Sketching inside a cylinder
RE: Sketching inside a cylinder
- - -Updraft
RE: Sketching inside a cylinder
RE: Sketching inside a cylinder
RE: Sketching inside a cylinder
Dan
www.eltronresearch.com
Dan's Blog
RE: Sketching inside a cylinder
if it where possible, i would sketch on the horiz, extrude cut to surface (cylinder wall surface) then extrude that cut (from the cylinder wall) again at 20 degrees down downwards for the duct.
Not possible it seems.
RE: Sketching inside a cylinder
Yes normal to the sketch, the centre of the sketch is exactly on the cylinder wall axis (28 radius from the bore (and part) centre.
The extrude cut is bi-direction. The cut away from the cyilnder (downwards forming duct) is fine, the reverse dir is the problem.
I've only been using SW for 3 weeks, this is the first time i've been really stumbed
RE: Sketching inside a cylinder
Dan
www.eltronresearch.com
Dan's Blog
RE: Sketching inside a cylinder
The exhaust duct changes section shape as it proceeds. I think I know how to do this using a lofted cut with a profile. However the 2 duct merge into a single duct.
Do i have to add a sketch at the end of the lofted cut to continue the extrude cut with a single duct?
RE: Sketching inside a cylinder
Nope thats the same.
I did try to draw a 3D sketch over the the weekend directly on the cylinder wall using the shadow of the wrap as a template.
I gave up as it was just too difficult and I dont think that would extrude cut anyhow.
RE: Sketching inside a cylinder
Dan
www.eltronresearch.com
Dan's Blog
RE: Sketching inside a cylinder
RE: Sketching inside a cylinder
Dan
www.eltronresearch.com
Dan's Blog
RE: Sketching inside a cylinder
I don't know how to 'share' a sketch.
Looking at the image, it appears as I want it viewing at that angle. I see you've added a 'cut extrude' to the tree, need to examine how you did that. Possiblily best if you post your modified part
Thanks
RE: Sketching inside a cylinder
Dan
www.eltronresearch.com
Dan's Blog
RE: Sketching inside a cylinder
Is it possible to 'convert' a wrap or the intersection of an extruded to surface outline to a 3D sketch and then extrude from there?
RE: Sketching inside a cylinder
How in world am I going to reproduce that?
RE: Sketching inside a cylinder
Use Sketch80 to create a Wrap on the bore
Use the Deboss option set to 100mm
Use the Pull Direction and select the line drawn in 3DSketch23
RE: Sketching inside a cylinder
Excellent! That's perfectly how I wanted it. Thanks
Now all I have to do is continue the cut with a varying section shape and merge the 2 ducts into a single. I'll have a play with what I have now and come back if I get stuck.
One other note. Having used Autocad paper model in the past to obtain the area of these ports, I can't find the same tool in SW. I need to see the area in the sketch, and the area as produced by the wrap. The volume of the duct would also be handy.
Thanks again, I learned alot today.
RE: Sketching inside a cylinder
RE: Sketching inside a cylinder
RE: Sketching inside a cylinder
RE: Sketching inside a cylinder
RE: Sketching inside a cylinder
I need advise on 'best practice' to form the duct. The duct at the cylinder end is split in two as per my prev. attachment, however this forms into a single duct as the duct progresses. As the section changes need to be precise I propose to sketch every few mm on the 'exhaust duct angle' plane. My question is this; should I sketch and form the duct as a single duct with a lofted cut and then add the vertical split at the cylinder end with a new sketch and extrude or start with the dual ducts and try to merge the loft.
Regards