Learning CAD with Alibre Atom3D

[JasonBModerator @jasonb]

For the counter bores that you asked about earlier first click the flat top of the head which will make it blue then activate 2D sketch

Draw a circle roughly over one of the through holes and dimension it's diameter, then using the concentric constraint click the through hole followed by the circle just drawn which will place it centrally over the through hole.

You could do the same for the other 3 counter bored or as I did use the circular pattern feature to place them.

De-acivate the sketch and then use cut extrude, you can either set a depth or if the fins have been drawn already select "to geometry" and click the bottom of one of the vertical slots as the place the counter bore will end.

Click OK and jobs done

You can see I have a lot less sketches at the side than your screen shot, the pale grey pair are the horizontal fins which I have suppressed as we don't need both

Edited By JasonB on 10/02/2019 19:14:55

[mickParticipant @mick65121]

Thanks Jason, that will keep me quiet for a bit!!

[David JuppParticipant @davidjupp51506]

Mick – I'd add that in each of Jason's examples, an alternative approach would have been a single slot profile in the sketch, extrude cut that, then feature pattern to get the required number and spacing of slots.

There is no 'right' or 'wrong' method – using feature patterns keeps the sketch simpler, hence easier to edit.

[mickParticipant @mick65121]

Hi. Jason, its been far too quiet of late! I've been trying all the methods you've demonstrated but I can't get the results in your screen shots. My screen shots are in reverse order ( can't even get that right!) With the sketch I've produced I get the warning that the sketch isn't closed when I exit sketching. The sketch will only rotate when the Y axis is selected, screen shot two, if I select either X or Z I get the result shown in screen shot 3 and that's before I click the okay tab. When I click okay on the rotated sketch I get the result shown in screen shot 3

[JasonBModerator @jasonb]

You need a horizontal line from ctr axis out to the edge of the head and a vertical line up the central axis which will close the sketch. If you look at my sketch again you can see these two lines, bottom one is red and vertical is orange hence a bit harder to see over the green axis line

[David JuppParticipant @davidjupp51506]

For more detail about 'closed' profiles – review this video.

[mickParticipant @mick65121]

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.

[JasonBModerator @jasonb]

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

[David JuppParticipant @davidjupp51506]

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.

[john wiltshireParticipant @johnwiltshire99912]

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

[JasonBModerator @jasonb]

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.

[David JuppParticipant @davidjupp51506]

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.

[TomkParticipant @tomk39956]

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

[Neil WyattModerator @neilwyatt]

Posted by TomK on 19/02/2019 23:40:02:

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

[Roger Page 2Participant @rogerpage2]

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?

[JasonBModerator @jasonb]

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

[Roger Page 2Participant @rogerpage2]

Thanks for your prompt reply

[TomkParticipant @tomk39956]

Posted by Neil Wyatt on 20/02/2019 09:21:47:

Posted by TomK on 19/02/2019 23:40:02:

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

Thanks for the reply. Neil

[David JuppParticipant @davidjupp51506]

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.

[john wiltshireParticipant @johnwiltshire99912]

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

[JasonBModerator @jasonb]

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.

[TomkParticipant @tomk39956]

Posted by David Jupp on 20/02/2019 19:36:56:

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.

David

Thanks for to reply

Tom

[SillyOldDufferModerator @sillyoldduffer]

Posted by john wiltshire on 20/02/2019 22:56:28:

…

.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

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

[David JuppParticipant @davidjupp51506]

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 support@alibre.com to get the code.

[John HinkleyParticipant @johnhinkley26699]

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

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