Learning CAD with Alibre Atom3D

Hi David. I should have said that I was getting the same situation when the sketch is, to what I think, is closed. In the heal box it says that it doesn't conform to the 0.01mm tolerance, but the sketch had snap to grid ticked and so I would assume each line would be closed.

In that pic you have a horizontal line splitting the sketch into two, trim that out.

On that Analyse box you have three results shown, click each one and it will show the error on the drawing which will give you an idea of what is wrong

Edited By JasonB on 16/02/2019 16:33:09

You can change the 'heal tolerance' value - but tat doesn't help if you have multiple loops on sketch.

Personally I find snap to grid a pain - but it may be helpful for some.

Hi,

i'm a complete beginner in the CAD area although I successfully got through the MEW magazine bits to date. However I have a simple question.

When I have a 2d sketch up on the screen what does " under defined" on the bottom of the screen mean?

I have "analysed" the sketch and it shows as having no errors.

One of the segments, which is a circular arc connected to two tangential lines, is coloured yellow.

How can I find out what is amiss in my sketch?

Regards JW

It is either the diameter of the circle forming the arc that has not been defined or the position of the circles centre point. David should be along later and can post a link to a suitable video.

This video was produced for Alibre Design, not Atom3D - but it illustrates how this works. The colour scheme used isn't quite the current standard. As the video states - best practice is to always fully define sketches, but this isn't forced on you.

I've just tried on my own system, it appears that you can do the following in Atom3D (my system also runs Alibre Design, so may not be entirely representative - would be good if somebody can check in Atom3D).

• Ctrl + Shift + N toggles the key for DoF colours (bottom right of screen in sketch mode)
• Ctrl + Shift + U toggles DoF callouts in the sketch - these make things even more obvious, but do clutter the sketch somewhat.

Question on animation.

Been looking at animation in Alibrie atom3d. I can get rotation and sliding of 2 items. Is this the limit or can

you get 2 separate parts to work together such as a plunger or a cam coming down on a leaf spring that would show the movement of the spring. The spring is not on a pivot, It is anchored to a flat surface.

Tom

Hi Tom

I don't think you can get items like springs to flex. Not only is modelling the spring accurately an issue, how does the program know which component should be flexing?

Neil

Having (I think) successfully completed the scriber, I notice that the triangle used to complete the point is still visible on the finished component. Does this go away on its own or does it need removing?

You get a fine red outline of all the sketches used to form a part, this can be turned off but I find it far more useful to have them showing as it makes it easier to locate a specific sketch if you need to go back and edit etc

Thanks for your prompt reply

Thanks for the reply. Neil

Tom, linkages like crank & piston can be made to work as in real life.

Atom3D doesn't have a 'Cam & Follower' constraint.

Part deformation, as others have responded is not supported.

Thank you Jason B and David Jupp for you quick replies.

However the CTRL+Shift+N and Ditto U do not work on my version

.Further magification of my sketch showed that the tangents to the circle were not connected for some reason. I have corrected this but still cannot get the sketch to be fully defined. Analysis shows no problem.

Is there a way that I can attach my sketch to a post so that others mre able than I can try to manipulate it?

John W

If you can take a screen shot of it then follow the directions here for how to put it in an album and then into your post.

David

Thanks for to reply

Tom

I'm not familiar with Alibre, but if it is like other packages, 'not fully defined' means that your sketch, or some part of it, needs to be dimensioned or constrained.

As an example, in FreeCAD (I'm not recommending it), you can sketch a circle on the X,Y grid of about the right size, say it happens to have a radius of 9.98mm. At this stage of the drawing process the package knows that the initial radius of a rough sketch might be unfinished. You have to give the radius an explicit dimension, say 10mm, before that dimension, the radius, is 'defined'.

Although the circle now has a defined radius, it's still not a fully defined sketch. because the exact x,y coordinates of the centre point haven't been set explicitly either. Until that's done, we have sketched a circle of agreed diameter that could be wrongly positioned, and is able to float around the drawing. This might be an error! Once the centre point of the circle is constrained or dimensioned to a point on the grid, the circle is fully defined - it has known size and position.

Sketches of real objects tend to be a good bit more complicated, what with tangent, vertical, horizontal, symmetric, angular and other constraints to contend with as well as dimensions. Look for something missing from your sketch in way of length, position, or relationship with another line.

There's no way of putting a sketch on the forum (only hosts text and jpg images), but you could link to a copy stored on a free hosting service like Dropbox or WeTransfer. May be possible for Alibre users to collaborate on the same design, support for that varies between products, and it's more likely on professional versions. FreeCAD requires manual coordination, Fusion360 supports teams in software, though I've never tried it. I don't know about the trial software.

Dave

Edited By SillyOldDuffer on 21/02/2019 11:33:13

Tom, you can post Atom3D files to the Alibre User Forum. To set up an account there so you can post you will need an access code - either PM me or mail [email protected] to get the code.

Now that I've quite got into AA3D and have drawn, or started to draw, a number of projects, I'm a bit worried what I'll be able to do with the files once the trial period runs out. I am still deliberating whether I want to invest the thick end of £250 in a year's full licence.

If the program is going to be dramatically disabled, I wonder if I should be extracting dxf 2d plans for workshop use?

John

Atom3D will still work as a viewer when the trial period expires. So you'll still be able to access your files but not edit them.

Of course nothing to stop you from producing DXFs or PDFs, just to be doubly safe. You could also export your 3D designs as STEP, which pretty much all 3D CAD systems can import.