Surface reverts back to original shape after trimming and a move

[Anonymous]

I created a surface and then trimmed it. I wanted to move this trimmed surface

but when I did the surface reverted back to its original form. 

Here's pics...The first one shows the trimmed surface and the

second one shows what happened when I moved it.

Thanks

[Alfred.NESWADBA]

Hi,

>> Here's pics

Instead of images please upload the drawings (state before and state after your modification).
The images do not give us any information about the type of geometry, associativity, distances and coordinates, ...

- alfred -

[Anonymous]

Ok, here are the before and after drawings.

top of vault first.dwg is before I try and move it

top of vault.dwg is after I try and move it

[Alfred.NESWADBA]

Hi,

>> I wanted to move this trimmed surface

>> but when I did the surface reverted back to its original form

There is other geometry in the drawing too, so I'm not sure what to move to see that the "surface reverted to the original form"

Look to the attached video and try the same steps ... does your issue show up when you are reproducing my steps? Or did I do anything different (I just moved the surfaces I found in the "*first"-drawing)?

- alfred -

[john.vellek · Accepted solution]

Hi @Anonymous,

Pretty strange behavior. While I look into this, a quick fix is to convert the revolve surface to Nurbs and then it moves properly.

Please select the Accept as Solution button if my post solves your issue or answers your question.

[Anonymous · Accepted solution]

It appears that you have created an associative trim for that surface and somehow eliminated whatever you used for the trim making the surface use last known locations for the trim.  When moving the object it re-trims relative to that object.  I didn't know it was possible, much less what to do it about it now.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I do however question your methods, 2D plines with thickness, and strange surfaces are difficult to manage, in my opinion.  I find using actual 3DSOLIDS much easier to manipulate.  Instead of changing the thickness of the 2D pline, extrude it to the proper thickness as a solid.  instead of creating a revolved surface, revolve a closed pline to a solid or trim a sphere of the proper diameter and height.

Commands to investigate:

EXTRUDE

REVOLVE

SLICE

SUBTRACT

INTERFERE

BOX

SPHERE

[Anonymous]

For some reason I was able to move the curved surface without it reverting to its past shape the last time I tried it. 

"Pretty strange behavior. While I look into this, a quick fix is to convert the revolve surface to Nurbs and then it moves properly."

When I started exploring surfaces in 2015 the tutorials explained that there were different states

of association and I wonder if that is what is going on. If I am going to move things around should I go to a Nurbs surface?

rculp, you have a point about solids but I just want something to be able to go through ideas quickly. 

I haven't done that much with surfaces before. I am interested in them now because they seem to be faster and easier to construct. 

I fooled around with surfaces in r14 but acad2015 has much more robust editing tools. Mostly I want to use these surfaces as a 

kind of sketch pad just to try out ideas. I am also competent with solidworks but the advantage of autocad is that it is  easy to 

move things around unlike solidworks which is a lot more involved.

Thanks everybody for the help!

[Anonymous]

Using this thread as evidence I would say it is incorrect to assume using surfaces is faster or easier than using solids.  Creating a solid by extruding a pline is just as easy as (or easier than) changing the thickness of a pline, same with creating the surface sphere and trimming it.

But then ...

[douglasgroom2k]

It's 2025 and I checked this thread for a similar problem and solved it a different way.

Problem: i created an orange cutting plane to trim my gray surfaces, when I delete the orange cutting plane the trimmed surfaces become untrimmed.

My solution:  Before deleting the cutting object, right click the trimmed surface and go to properties, at the bottom under ASSOCIATIVE TRIM click the drop down menu and "remove".  Then you can delete the cutting object and your surface will remain trimmed.  

Cheers,

-Doug