corner blend when extruding land

[pete1968]

the corners do not blend right when extruding this profile to create a land

[Bishop]

I'd just upload the file so you could see what I did, but since you're running 2009 you wouldn't be able to open it. I can't remember for sure - it's been a while since I used 2009 - but I think all these tools work more or less the same, although your dialog boxes will probably look a little different.


step 1.jpg
step 2.JPG
step 3.jpg

[pete1968]

thanks i see what you did and I will give that a try

[pete1968]

after looking at what u did . the thru cut-out needs to be parallel with the floor and it looks like from the picture its parallel to the top plane. Can i offset the workplane i used to create the sketch up 3 inches and do it that way. the sketch is drawn parallel to the floor

[JD Mather]

Before creating the feature.
Thicken/Offset as surface body the pie face of the solid at desired offset height.
Then Extrude with Between option between the solid and the offset surface body (which could be an offset of any curvy face (yours is a simple conic)).

[Bishop]

after looking at what u did . the thru cut-out needs to be parallel with the floor and it looks like from the picture its parallel to the top plane. Can i offset the workplane i used to create the sketch up 3 inches and do it that way. the sketch is drawn parallel to the floor

You could, sure, but it's probably not a good idea to do it that way, from a manufacturing perspective. I'm assuming that this part is going to be cast? If so, having the extrusion normal to a plane that is angled is going to SEVERELY complicate your manufacturing process. You'd really be better off having the cut start off straight up and down, and then use draft to adjust for whatever the pull direction will be out of your mold. Even if you're looking to machine this, it'll be a pain in the butt, because there will be some places where you have to undercut, and that will require more tool changes with more tools, as well as more machining operations.

[pete1968]

I see your point. I am modeling this part to use to create cnc program. The blank is a solid piece of alum. I know the land needs to be parrallel to the bottom because something mounts on the land by tapped holes which are shown in the same plane. But the though cavity might be able to cut straight thru.

[Bishop]

Okay, I think I see what you're saying now, and it should be a simple change. In the first step, make your sketches on a plane set up like I had it, but don't do the EXTRUDE yet. Make a plane parallel to whatever you want, and offset at the height you want away from the curved surface. Do an EXTRUDE BETWEEN the two, and the blank of your land should be set up the way you want. Do your cut the way that I showed, still cutting from the same plane that the sketch was on, and you should have what you need.

If this doesn't make any sense, let me know and I'll do screen shots again.

[pete1968]

I'm glad I ran across this forum. I have learned quite a few new things just from my 1st two posts that I will use down the road. I'm just a hack at this sort of. No formal training just but some books and studied on my own. When I switch to inventor from autocad I found Inventor a lot easier to use for what I need . Which is creating soild models to machine off of when customer does not have one. .I use the insert autocad file feature alot. Where I create the 2d geo in mastercam and save out as a DWG. I'm alot faster in mastercam drawing than in inventor LOL. I know I need to constran things more or learn how to create the 2d in inventor. I'm want to look into some training at some point cause I enjoy modeling ,creating prints etc.