Extrude along path.....need help

[Steven Kenzer]

I'm having trouble with a very simple extrude along path command. 

 

Here's the task. I need to run a 1/2" diameter rod around a 36" diameter circle. Sounds simple, I know but..everything I've tried fails. I first create the 36" D circle, the path. Am I correct I need to convert that to a polyline? Then I draw a 1/2" diameter circle, the profile. Do I need to convert that profile circle to something other than what it is? I've tried all kinds of combinations to no avail....all fail to create the object I need. If someone could help me out here, I would be most appreciative. What's crazy is I've done this on many occasions before...can you say "Senior Moment"? :-) Thanks everyone.

[PVA - Admin]

I kept both objects as circles and the extrude seemed to work as expected in 2017 SP3. I did one with the center of the profile on the path, one with it against the outside of the path and one with it inside the path:

 

Extruded circle rod.vwx

[Kevin McAllister]

You shouldn't need to convert anything. A circle and a circle should work. I would recommend using a sweep for what you're trying to do though. Place a 2d loci and your rod diameter circle 36" apart (loci to the left side) and Sweep.

 

Kevin

[bcd]

+1 for sweep. Select both locus & circle and Model>Sweep

Edited May 5, 2017 by bcd

[Steven Kenzer]

Sweep + loci worked well...thank you!

 

Jim, I'm still not able to do this as I typically did and as you showed doing it??? No clue why that isn’t working. I am on 2017 SP3. No need to convert these 3d circles for that process, correct? You drew a large circle, then drew the smaller one, placed profile circle where you said and it worked. I go through that same process and it fails. I was never aware the location of the profile made a difference. Baffled but all good with Sweep command for now. I'm going to keep playing with this to see what I'm doing wrong in terms of Jim's technique.

 

Thank you all.

[Pat Stanford]

With an extrude along path, it does not matter where the profile object is, it will always be extrude (initially) along the center of the profile object. After you make the extrude you can Edit Profile and move what ever point on the profile object you want to ride along the path to the zero zero point.

 

Try this with the extrude along path in a new blank document.  Draw two circles. Select them both. Choose Extrude Along Path. Make sure the one you want to be the Path is highlighted. Click OK.

 

Does that get you a torus shape?

[Steven Kenzer]

Thanks, Pat.

 

Yes, I've never been concerned about the location of the profile before. Having said that, I just opened a new blank file, plan view, placed one circle in, then placed a smaller circle in. Selected both and used the larger circle as the path, smaller one as profile and.....failed once again!  See screenshots.

 

I'm starting to wonder if this is some malfunction of VW for some weird reason. Is it possible something is corrupt here??

[Andy Broomell]

When you do the Extrude Along Path command, make sure that the 36" circle is highlighted in red, not the 1/2" circle. Otherwise it's using the wrong circle as the path which in this case causes it to fail.

 

EDIT: We posted at the same time. If that's not the issue, then I'm stumped!

Edited May 5, 2017 by Andy Broomell

[barkest]

Its because you have Fix Profile selected. Turn it off and it should be fine

[Steven Kenzer]

The beauty of this forum. Yup, that was it! The other day, I was curious about that setting, so switched it on. Unfortunately, forgot to turn it off. Thanks so much everyone.

[barkest]

Out of interest you would use Fix Profile when you line up the profile with the path (see attached)

 

And for even more interest  (as if that wasn't enough) the direction of the path affects how the profile is extruded along the path. Typically I draw clockwise or check the shape and reverse the direction if it is not clockwise. It then gives predictable results if you need to move the profile from the centre of the path by editing the profile.

 

So in summary its not that crazy to convert the circle (path) to a nurbs because that way you can control the direction of the path and get those predictable results 

Edited May 5, 2017 by barkest

[Steven Kenzer]

Great to know......thanks again.

[Kevin McAllister]

The reason I think using a Sweep is better in this instance is because it allows you to adjust the radius/diameter of the path "circle" easily later on. You can just edit the Sweep and move the profile circle closer or further away from the loci. Extrude Along Path will convert the path to a NURBS curve which will be harder to adjust.

 

Kevin

 

[Steven Kenzer]

That's a good point...thanks.  It does seem simpler to change path with Sweep than EAP. I'm back on track now.