Creating a rib on a boss to a curved surf

[cityjack]

I need to create a rib on a revolved boss but the boss is extruded up to next surface which of course is not planar. How can I get my rib to attach at any point around the boss? Its like if I could cut a section through the boss and use edge from the section would be great. But then as the rib thickens both directions from the section sketch the rib will become buried into the surface as well as fall away from the surface. Do I really need to surf this in? I can do it by projecting curves and curves thru points and boundary blending it in then solidifying. Just alot of work for a lousy rib. Any suggestions please. Just a basic molded part that needs gussets on my hollow bosses. thanks.

Sid

 

[sip]

cityjack


I believe the rib feature specifically takes care of this. You only need to make a single line connecting the inside and the outside surface the rib connects to, and it will take care of the detail you describe.


2007-10-15_183645_rib.prt.zip


Sip

 

[mjcole_ptc]

I figured out several ways of doing it and most of them didn't work. This one did and a may get an even simpler method after a little more thought.

Something like this?

PTC needs better Group Functionality walking around the earth or 25% of it seems easier than their Group functionality. I'll rant on that later. Don't really have time to explain my method in detail but will later on.

Here's the simple explaination. Create some sort of patterned group with references you'll need for your rib. Since I patterned the cylinder but wanted a reference pattern for the ribs I did it as 4 midplane revolves of 90 degrees. to make sure that the rib sketch always hit the cylinder and the base surface which varies in height as you mentioned I created a projected curve colinear with the plane used for the 4X revolve pattern and projected it onto a COPY surface of the variable surface I wanted the rib to extend to.

I had some trouble with the Rib Sketch not patterning properly so I created a Spline from the curve used for the projection and the projected curve endpoints.
http://picasaweb.google.com/michael.j.cole/ProE_forum_pics/photo#5121861565375297522
Michael

 

[cityjack]

Sip,
your use of the rib isn't quite what I was referring to. it is exactly what Mike is showing. Thank you anyway Sip. Mike; I was trying other methods before you replied and I got it to work another way as well. easier I'm not sure. I am not totally sure of how you are patterning or projecting your curve. I will wait for your detailed explanation if you would be as so kind. I need to learn alternate ways to get things done. Wildfire is a beast of a different sort comapred to anything pre-wildfire. Here is what I did. Someone elses model too mind you that I inherited. I removed the draft from their boss. I made an extrusion offset from the top of the boss where I wanted the top of the rib to start up to a chosen surf ( base of the boss). I then created 2 different blended surfs using the intersections of the top of the new extrusion with the boss and the bottom of the new extrusion with the selected base surf of the part. This giving me my tapered profile once surfed. By the way I could not sweep a cut around the entire boss, it would only go 180 deg. Anyway I merged the 2 blended surfs and then solidified. I now have my solid cone going around the boss and right up to the surf of the base all the way around. Perfect. Now I just cut away the material w/ extrude up to selected surf from in between the ribs that I don't need from the same surface that I created the initial solid offset extrusion from. Hide the blended surfs because they were not consumed by the solidify. Now to put the draft back on to the boss. it works. No patterning involved. I am very curious to see your method with the patterns though. Thanks Mike.

Sid

 

[sip]

Sid


Sorry I misunderstood. I didn't read your post close enough.


Sip

 

[dgs]

The rib feature that sip described should work. You may need to create a curve oby interection on the surface at the base of the boss to get some geometry to anchor the rib to. Once that's done, it should work fine.


BTW - This was the same problem pre-Wildfire, it's just that the clicks to get there are different.

 

[mjcole_ptc]

Solid works does allow you to sketch an incomplete line and will extend it up to the next surface which Pro/E does not do for you.

Will PTC improve their functionality?
Probably not they'll just call Solid Works a mid range package and be done with it.

Solid Works Rib

Sip did point out what was necessary to have the feature complete and I just implemented a workaround to achieve the result.


I modeled the part as a practice exercise on SW and added an offset angle to the three line sketch and it let me rotate by 60

 

[cityjack]

Sip,

You were correct along with dgs. Sketch a curve on top of the boss. Project it onto the surface in question. Sketch your 1 line rib sketch. Tie it to the curve and to the side of the boss and waLA. It works. Why in gods name do I pay maintenance to PTC. You guys are the real deal. Model on my friends. Model on. thansk to you all. Not a bad excercise. 3 ways now to skin that cat.

Sid