Any CAD/Engineering drawing gurus around?

[m_c]

I'm doing an HNC design module at the moment, and I need to draw an assembly constructed from 25mm box section.

How should you draw the box section in CAD?
Should you show the curved corners, or are simple square corners acceptable?
And would you normally draw the hidden internal structure?

The actual assembly isn't that complicated, but there is nothing in the course work covering hollow sections.
I've had a look through the recommended/provided Manual of Engineering Drawing, but it doesn't seem to cover how you'd represent hollow sections.

The assessment only calls for front and side elevations, with all dimensions required for manufacture shown, along with a sketch of the general layout, so they're not expecting a super detailed drawing, but I'm not entirely sure how much detail they're expecting given the limited materials sizes to be used.

 

[dholdi]

I would draw it as follows :-
In cross section - Inner and outer solid lines with the radii and cross hatched.
In plan and elevation - Inner dashed line and outer solid.

 

[Agrismith]

I'm doing an HNC design module at the moment, and I need to draw an assembly constructed from 25mm box section.

How should you draw the box section in CAD?
Should you show the curved corners, or are simple square corners acceptable?
And would you normally draw the hidden internal structure?

The actual assembly isn't that complicated, but there is nothing in the course work covering hollow sections.
I've had a look through the recommended/provided Manual of Engineering Drawing, but it doesn't seem to cover how you'd represent hollow sections.

The assessment only calls for front and side elevations, with all dimensions required for manufacture shown, along with a sketch of the general layout, so they're not expecting a super detailed drawing, but I'm not entirely sure how much detail they're expecting given the limited materials sizes to be used.

I've done cad as a module of an HNC albeit civil engineering. The level of detail they expected at HNC level was minimal. It was less about drawing and more about showing you know what to include in a design drawing and you have a basic knowledge of the programme. Needed to use a few different shapes, extrude a shape, use layers, put a void in an object and so on.
Also had to make 1 glaringly obvious error then write about how cad allowed you to see it.

 

[bricol]

Do you have to show hidden detail?

If hidden detail doesn't add anything, I don't show it - but I don't have to pass any exams.

 

[m_c]

Do you have to show hidden detail?

If hidden detail doesn't add anything, I don't show it - but I don't have to pass any exams.

It doesn't say.
Going by my interpretation of what they're looking for, and @Agrismith 's reply, it's more about the generality than specifics.
It forms part of a design report, so it's only one part of the assessment, but the criteria does appear to put a reasonable weight on it
The course work doesn't really go into much detail beyond learning the basics of AutoCAD, which is why I'm unsure of the level of detail that they expect.

The official material to be used, is simply 25mmx25mmx2mm box section, so it doesn't list any radii, but I know box section comes with certain radii.
I have already modelled the project in basic form in F360 to make sure everything fits where it should, but I'm now drawing it in AutoCAD as that's what the module is based on.

 

[Agrismith]

It doesn't say.
Going by my interpretation of what they're looking for, and @Agrismith 's reply, it's more about the generality than specifics.
It forms part of a design report, so it's only one part of the assessment, but the criteria does appear to put a reasonable weight on it
The course work doesn't really go into much detail beyond learning the basics of AutoCAD, which is why I'm unsure of the level of detail that they expect.

The official material to be used, is simply 25mmx25mmx2mm box section, so it doesn't list any radii, but I know box section comes with certain radii.
I have already modelled the project in basic form in F360 to make sure everything fits where it should, but I'm now drawing it in AutoCAD as that's what the module is based on.

Have you searched the library on autocad to see if there is box section you can import ??

 

[Munkul]

Side view of SHS I'd show outer dimensions only with no hidden features.
End profile I'd show wall thickness and radii.
And either a numbered balloon referring to a BoM/Cut list, or a note saying exactly what it is.

A good drawing shows exactly what and how something is made, but a great drawing communicates all the detail in an easy-to-understand format so that the fabricators don't mess it up

 

[bricol]

I might dimension wall thickness to make it clear, but I can't think of any occasion where I have dimensioned the radii - it's made to a standard, there should be no need. All I usually do is label it - 25x25x2 SHS.

Favourite note on hollow section drawings? "cap all open ends"

 

[Agroshield]

A good drawing shows exactly what and how something is made, but a great drawing communicates all the detail in an easy-to-understand format so that the fabricators don't mess it up

Agreed.

If you followed some of the advice above, you would be showing hidden detail lines everywhere in plan and side elevations, which are totally unnecessary and clutter the drawing.

Where you might usefully use hidden detail is a non-symmetrical section (like a C-channel) so that in plan it is clear which side is the web and in elevation you know if you are looking at the inside of the C or the outside.

Another approach with regard to the corner radii is to acknowledge them where they matter - if the presence of the corner radius means a butt joint needs some coping/preparation so you do not have a standard weld gap at the sides and a chasm at the top and bottom, it shows you have thought about the issue and drawn the diagram to suit.

 

[clift_d]

Coming from a construction perspective, I would always encourage people to show correctly radiused corners on steel sections in detail drawings, otherwise you cannot get a realisitic sense of how any connections might work, or the final appearance of the finished piece.

 

[Munkul]

Coming from a construction perspective, I would always encourage people to show correctly radiused corners on steel sections in detail drawings, otherwise you cannot get a realisitic sense of how any connections might work, or the final appearance of the finished piece.

You'd do this in an exploded view seperately from the main assembly/weldment, if its a complex drawing then too many details are confusing.
Its a thin line to walk. Some designers get it right, some get it wrong...

 

[Erie Fred]

2-d cad or 3d parametric solid modelling ?

 

[daedalusminos]

I'd say it also depends on the size of the object Vs the level of detail....if this was a chair, front and side then the detail would be lost....if you wanted to show the detail of a welded joint then show the wall an radius.

I'd only show enough detail to convey the information required to produce the item.

 

[bricol]

Click of a button of course when producing a 2D drawing from a 3D model to turn on or off hidden detail. Or indeed what NX term "smooth edges" - the thinner line, lighter line type to indicate the start/end of radii, folds etc. But more long winded if only 2D, but hopefully all hidden detail on a specific layer and turn it off and on as required.

My last check on a drawing - can I make it? Which from some of the drawings I've been provided with, isn't a question a lot ask . . .

 

[Tinbasherdan]

I’d be surprised if it needed to be that detailed, CAD is one of the few things I don’t teach but I don’t recall anyone ever creating something that fancy. If you’re determined, I’d draw it as a solid on f360 and use the shell command