Two objects

[mune72]

This a quite easy question but the search in the forum yields too many false positives and the video tutorials don't talk about it becase is too simple.

I have a file A with an electic motor.
I want A to be a model, so in the file Z I might have two motors created from the model.

I tried to open the file A, copy the motor (the union) and paste in Z then move the motor from the origin and paste again; but I can't get two motors.

How do I do such a simple thing? Thanks

I'm using FreeCAD 0.12 rev 5382 on GNU/Linux Ubuntu 12.04 and it is coming from its repository.

I attach the (very simple) motor file.

[NormandC]

I'm not sure of what you are asking.

You want more than one instance of your part in the same document? There are a few ways to do that. Copy/paste works, I tried it on a different model. Please explain in more details what you did, and what's the result. "I can't get two motors" is simply not enough information.

Other ways are:

• "Part --> Create a simple copy" menu. This will produce a copy that is not linked to your original and that cannot be modified, of course it can be moved.
• Draft Clone. The copy is parametric which means it is linked to the original. If you make changes to the original, the copy will update too. It can also be scaled. This is a new tool in the Draft workbench only available in the 0.13 version. You can update FreeCAD to this version by using the PPA repository. It's explained in the Downloads page. https://sourceforge.net/apps/mediawiki/ ... A_packages
• Draft Array. This creates multiple copies on an orthogonal grid, or in a polar fashion. Not sure, but I think this was added to v0.13 too.

But the "real" way to do this is not implemented yet. The Assembly module, which is in early development, will allow us to add as many instances of a part in a document as we want, and to position them with rules such as: mate two faces together (click on a face of part A and click on a face of part B), align radially (click on cylindrical surface of part A, click on cylindrical surface of part B) and so on. It's gonna be great! Maybe we will see this in v0.14.

But maybe the problem with copy/paste you have is because there are a few things wrong with your model. I opened it, and nothing was visible in the model view. Here's how the Project tree looked like:

• If nothing is visible when "Fusion" is in a visible state, it's because the fuse operation failed to produce a shape.
• There's the "Motore A" group. It's empty. Was there something in it?
• I have no idea how "Shell" was created. FreeCAD tells me it is not a solid, nor a shell (in FreeCAD terminology, a shell is a closed volume with empty space inside)
• Cut001 has lost references to the objects used to create it. From v0.13's new dependency graph tool, I'm guessing you first created "Cut001" out of "Cut" and "Invito vite 1" then copied it to "Cut002". This switched dependencies to the latter.

This is what the dependency graph for your model looks like:


To me it is clear why the "Fusion" object failed. "Shell", "Cut001" and "Cut003" all share the same space, with faces exactly the same. This is a big no-no with boolean operations. It will fail every time. Objects can intersect, but cannot share exactly the same space.

I think it would be best if you redid this model from the start.

[mune72]

Thank for you reply

I'm not sure of what you are asking.

You want more than one instance of your part in the same document?

Yes, you guessed it right

[8< snip ...]

• "Part --> Create a simple copy" menu. This will produce a copy that is not linked to your original and that cannot be modified, of course it can be moved
  [8< snip ...]
• There's the "Motore A" group. It's empty. Was there something in it?

ops, it is garbage of my previous trails.

To me it is clear why the "Fusion" object failed. "Shell", "Cut001" and "Cut003" all share the same space, with faces exactly the same.

For me isn't clear but I trust you

I think it would be best if you redid this model from the start.

Maybe,but it's up to my lazyness.

Using "simple copy" it worked (despite something odd the screw holes). Thanks

[NormandC]

To me it is clear why the "Fusion" object failed. "Shell", "Cut001" and "Cut003" all share the same space, with faces exactly the same.

For me isn't clear but I trust you

Actually I was wrong! It's only "Shell" that causes the Fusion to fail. The "Shell" object's integrity is completely shot. Meaning, it's garbage and you won't be able to do anything with it (no more cuts or fuses).

What I was talking about is good practice when you use booleans. You make sure the part cutting another exceeds a little everywhere to minimize problems. Much as explained here, the advice is written for OpenSCAD but it's valid for any CAD software: http://www.iheartrobotics.com/2010/01/o ... -time.html

Maybe,but it's up to my lazyness.

Well, of course it's your model and your time, but as I said the Shell object is unusable, it may prevent you from completing your work later on.

Using "simple copy" it worked (despite something odd the screw holes).

You have Cut001, which has 2 holes. You have Cut003, which has 3 holes. They overlap each other. If you have fused them, that's the "odd" that you see. Cut001 fills the hole of Cut003... If they are not fused, simply hide Cut001 (right-click on its label in the Project tree or select it and hit spacebar) and you'll see that you have no hole problem.

[mune72]

Thank for your reply.

Maybe,but it's up to my lazyness.

Well, of course it's your model and your time, but as I said the Shell object is unusable, it may prevent you from completing your work later on.

Right after I wrote I thought the same: later it can create big problems, so I have already spent the last two hours restarting from scratch (I'm refacing the zooming of Shimano gear).

[NormandC]

I suggest you save often and at important steps change the file name (add "_rev1", "_rev2"...) so if at some time something weird happens you can go back to a previous version and not lose too much work.

[mune72]

All done!
Many thanks

Attached is the resulting draw

PS I haven't clear why the first is group and second is not. For me, thay both should have been of the same type.

[NormandC]

Are you talking about "motor001 (Mirror #2)"?

It is not the same type because it's only a mirrored copy. And the first object is not a "group": a group is represented as a folder. All the items under "motore" are the objects that were used to create it. It's kind of like a history of its creation. There is no such history with motore001 since it's a parametric copy of the original.

I made a geometry check on your model again. All shapes are fine except for your "pignone" object.



I think the scaling of the shimano part causes this problem. But I don't know how to fix this. In any case this does not seem to prevent boolean operations on it.

[mune72]

In any case this does not seem to prevent boolean operations on it.

Right, I cosider the issue solved.

The PS was just a curiosity, thanks

[tanderson69]

In any case this does not seem to prevent boolean operations on it.

Corrupted models might not cause immediate problems, but they will haunt you. My advice is to fix the corrupted models whatever it takes. This will be a hard lesson.