Renaming datum shapes

[agryson]

The datum term you are mentioning refers to the specific field of geometric dimensioning and tolerancing.

When did geometric dimensioning and tolerancing become 3D modelling?

The current "datum planes/lines/points" in FreeCAD that we are talking about here are construction features to help in modelling the part. Not to do GD&T.

Jeez, I feel like I'm trying to define the colour blue to a blind guy.

We're not doing just 3D modelling here, we're doing part design, and I don't know about you, but when I'm designing a part, I like to be able to define elements in that part that are critical to its dimensional accuracy during the design process. Datum elements are vital to doing that.

We went from "never seen it in 20 years experience" to Autodesk, Dassault Systèmes and PTC all using it in their products in some fashion during the design of the part. If you like to totally divorce geometric dimensioning from part design, fine, that's your workflow but just think for a second that maybe other people work differently.

I came in to the discussion because someone asked for a native English speaker with CAD experience to weigh in. I did. But if that's not good enough because you became too emotionally invested in your francophone interpretation of things, fine, let's go full 1984 newspeak and delete useful words from the lexicon.

[agryson]

Add-on to my previous post. Rereading it, I come off as pi$$ed rather than my intended tone of incredulous/frustrated.
I understand what you're saying @NormandC, these are just reference elements at the moment so why complicate things with this nuanced distinction between a datum plane and a reference plane (especially when datum U reference) - it's just I don't agree with divorcing GD&T from Part Design.

My logic is that since the distinction is already in place, why remove it? The argument to remove it in english for me is just not a strong one.

Functionally speaking, we could name them simply reference and add a toggle to make them datums - but that would require extra dev for little benefit until we explicitly differentiate in other areas like TechDraw etc.

Edit: To close, if "datum" really causes so much hassle for everyone except me, the most technically correct term would be "Reference X" where X is plane, line or point.

[Jee-Bee]

I don't know if somebody has possibility to check what ISO names it. since ISO is multi language i think.
But i can imagine that ISO in Englisch called datum a datum but in lets say french the french word for reference...

[nemesis]

it's just I don't agree with divorcing GD&T from Part Design.
......
Edit: To close, if "datum" really causes so much hassle for everyone except me, the most technically correct term would be "Reference X" where X is plane, line or point.

Fully agree, maybe one day we will have a GD&T workbench / DVA workbench (once we have assy workbench)

I would keep datum in english and put the appropriate one in other languages... in french "reference"

I have access to ISO norm, but unfortunatly only the english version, nor french and german ones

[renatorivo]

agryson wrote:
it's just I don't agree with divorcing GD&T from Part Design.
......
Edit: To close, if "datum" really causes so much hassle for everyone except me, the most technically correct term would be "Reference X" where X is plane, line or point.


Fully agree, maybe one day we will have a GD&T workbench / DVA workbench (once we have assy workbench)

I would keep datum in english and put the appropriate one in other languages... in french "reference"

Just to see what others are doing with Datum (GD&T Datum feature)
https://knowledge.autodesk.com/support/ ... mtc-french
http://help.solidworks.com/2016/Italian ... oductName=

All translate référence/riferimento/...

[sgrogan]

I'd really, really prefer to create plain planes than "datum" planes.

When did geometric dimensioning and tolerancing become 3D modelling?

IMHO...
A plane is not a part of the physical geometry. For me "datum" implies some sort of GD&T. Usually defined by "datum surfaces" not datum planes. These surfaces are from the physical part not some reference/theoretical location. Pre-using "datum" invites future confusion.
In other software I've used auxiliary/additional/reference/construction "planes" are created from the reference or construction geometry menus.
Again, in my opinion, call them Plane001 or UserPlane001 and let the user rename them.

[triplus]

It's likely a local (standards) thing. If you follow ANSI/ASME you will likely use the term Datum (you could use the term reference or base but the common term to use is Datum). If you use other standards you likely use the term Point, Line, Plane ... and in tolerance related tasks you use the term reference before it.

I checked the literature in my language and it is true sometimes the term datum is translated directly but overall the term reference is used when it comes to tolerances. Plane therefore becomes Reference Plane. Or a Point becomes Reference Point.