How to force a coincident constrain

[ClaudeG]

Hi, can somebody help me.
How can I force a coincident constrain with the rear leg (Patte arriere) and back rest (Dossier).

 

[albie0803]

Assuming you want to sit the backrest onto the flat sections of the rear legs, then you can't. The back rest will need to be conical in shape in order to tangent connect to both legs. It will work if the flat sections were vertical and not angled.

 

[ClaudeG]

Hi Albie0803,
this is exactly what I want!

 

[HaroldL]

How can I force a coincident constrain with the rear leg (Patte arriere) and back rest (Dossier).

One way is to create a Boolean Subtract on the leg by positioning the back where you want it. You'll need to edit the leg in a separate window to create the Boolean Subtract.

That will create the exact shape in the assembly for the back to fit into.

Here's an example, you may need to adjust the back angle and position but I think you'll get the idea.

 

[ClaudeG]

Hi Harold,
What I did to create the angles cut, is with a truncated cone, whish I substract from the leg.
But now I need tp put the back rest to the leg; if no soccess, that will be not confortabe.

 

[ClaudeG]

Since I cannot constrant properly, I tryed to move it using the command Move a component a precise distance. What ever axe I select, il only move up or down.
Why is that.

 

[HaroldL]

Do you have any constraints that are restricting the movement?

Have you downloaded the package file that I modified with the Boolean Subtract feature?

 

[ClaudeG]

Hi Harold, I just downloaded it now. Yes you are right, I had a constran left which interfere with the move command. I will checked what you send me and let you knoe how it goes.
Claude

 

[ClaudeG]

Hi Harold,
It works. But, I would like to understand.
I see you make coincident the Dossier YZ-Plan with the assembly YZ-plan ; how do you specify Dossierlan-YZ?
I also see, the is constrain Angle(1), but it is de-activated, why?
Thanks for the help!
I still novice on this software.
Claude

 

[ClaudeG]

Hi Harold,
I found how to center dossier YZ-Plan with the assembly YZ-Plan.
If I put the disabled angle constrain, it does not work after for following coaxial constrain.
So I dont do it. But the dossier always stains vertical and I am not able to force coaxial (4), the system gives me a conicident constrain.

 

[HaroldL]

Claude, IF you are working with the packaged model I uploaded then you can delete the angle constraint, (I should have deleted it before I packaged the file). I used that initially to try and get the dossier oriented correctly or at least as close as possible to what you had in your assembly model.

If you move the cursor over the constraints listed in the Design Explorer you should see the corresponding geometry highlight on the assembly in the work area.

As I stated in my post #4, and demonstrated in the package file that I uploaded, if you edit the leg in a separate window and Boolean Subtract the Dossier from it, at the position and orientation you want in the assembly, then that will give you an exact shape feature to which you can constrain the Dossier in the assembly model.

I should have stated that in order to change the angle of the dossier in the assembly you need to edit the Boolean Subtract in the leg model.

If you can, take a screen shot of the issue you are seeing and post it on the forum so it is easier to understand the questions.

To help clarify the work flow here are some images of the model:

This is the leg I used to create the Boolean Subtract:

This is the Boolean Subtract in Edit Mode. The Angle Constraint is highligted. This is where you can control the angle of the Dossier in the assembly


To exit the Boolean select either of the two buttons on the LH End of the Ribbon

 

[ClaudeG]

Harold, I did not do any modification to your file; I want to be able to do it from my file.
In my file I did process similarly to produce the cut on the top of the leg, but I used a tool called "outilde coupe...".
I saw how you did it and chage mine to do like your.
I will do that change and comeback to you.

 

[ClaudeG]

Hi Harold,
everything woks; I did as you describe.
I am learning this by myself; its bad there is no books to learn.
Previoussly, I was using Sketchup, which I easily master, but I purchase books from Bonnir Roskes at 3DVinci. She is professional civil engineer. I already ask her if shi would be interested in writing book on Alibre, I have never receive an answer!

Thanks for the help. I will become better at using it.

 

[HaroldL]

Have you watched all the training videos for Alibre that are online? There are more on YouTube, here and here.

And, of course, you can always post your questions here on the forum.

 

[ClaudeG]

Hi Harold,
I already look at videos, and will check what you sent me.
Thank
Claude