topic Re: dimensioning in scale in 3D Part & Assembly Design

dimensioning in scale

Model_1975 — Mon, 27 Jul 2020 13:40:08 GMT

Hello community,

I´d like to make a technical drawing of an model which I created. This model is a small plate and it has the dimensions 18x18x1,6 [mm]. Now, because it´s so small I created the views in scale 4:1 (4 times bigger than in real life).

My problem appears when I am dimensioning the 2D-view. The view is 4:1 but the measurement is like 1:1 (it does not multiply with the scale):

1:1 Real model: 18mm

4:1 scaled model: 18mm (but normally it should be 4x18mm = 72mm)

When I make a sketch in the drawing and make a dimensioning of it, it makes the correct scaling operation.

As an Info: I didn´t took the "View Model Notes"-Option. I did the dimensioning all manually for better overview.

Could it be that the geometries of the model can not be scaled properly or do you have any idea how to get rid of my problem?

Thanks in advance!

Re: dimensioning in scale

BenLoosli — Mon, 29 Jun 2020 14:46:59 GMT

Is the part 18x18 or 72x72?

Just because the view scales, your part does not change size. It is still 18x18 and dimensioning on the drawing should reflect the model size, not the view drawing size. I would certainly be upset of I made my part to the drawing (72x72) and find it doesn't fir in the 18x18 space I have for it in my assembly.

Re: dimensioning in scale

Model_1975 — Tue, 30 Jun 2020 08:18:25 GMT

The Part is 18x18 in reality and so it should be.

The reason why I asked: I read that if I use a scale factor the measurings should also be adapted - here a part of the text where I read it:

If the workpieces are very small, they are shown enlarged in the drawing, namely on the scale:
Magnifications: M 2: 1; M 10: 1 etc.
The scale M 10: 1 says that 10 mm corresponds to a natural length of 1 mm in the drawing.
In other words, the drawing is ten times the size of the workpiece.

But: When I saw a scaled drawing I didn´t multiplied the measurements with the scale factor. So far it went just right. I just looked up an official 3M drawing which is scaled 2:1 (also up to 4:1) and the measurements in the scaled drawing are the real measurements. I have to add that there is a hint in the title block where it´s said: "DO NOT SCALE DRAWING" and I think with this hint the calculating of the measurements are unnecessary.

I would prefer to take the real measurements into my drawing (not the scaled ones) and add the hint not to scale the drawing - What do you think?

Re: dimensioning in scale

BenLoosli — Tue, 30 Jun 2020 16:42:47 GMT

The drawing is just a 'view' of your model. You can magnify any drawing view to get a view that shows the details of your part. The model does not change size.

We have the 'Do Not Scale" note on all of our drawings. The only time you will ever get a full scale drawing is if you use a plotter and use the full sheet size. We seldom do that. Our designers typically plot to C-sized drawings, even if the original is a D or E. They also do a lot of printing to a tabloid sheet on laser printers. None of these will give an accurate scale.