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Autocad 2007 1

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MauroMalacara

Industrial
Oct 15, 2003
19
MX
I have a drawing in inches. Is there a way to convert it from inches to millimeters?

Thanks for your help....
 
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You must scale the drawing up or down to convert. Multiply by 25.4 to go from inches to millimeters (.03937 to go from mm to inch). The other thing you will need to change is your dim style to make sure it now measures and appears correct after the change.

"Everybody is ignorant, only on different subjects." — Will Rogers
 
As far as I know, regardless of what unit you did your design in, if you draw on a 1:1 scale in model space, all you have to do is specify the units and it will convert to inches or whatever. In the old days the command was "units" and then you went from there. I don't think you have to actually convert the drawing because 25.4 units will be equal to 1 inch..... unless i am mistaken here.

Ratso
AutoCAD and Inventor
 
Scale the drawing who was your teacher?

Go to your dimstyles and click on the tab that says
primary units. You can figure it our from there.

Don't waste your time scaling the drawing. If you have
to scale a drawing to get the right dimenions you should
not be drawing in AutoCAD or giving advice
for that matter. Scaling a drawing not only affects the
drawing but how the file gets trasferred.

Remeber Garbage in Garbage out.

Andy
 
Remember though. AutoCAD does not know the difference between 1 inch and 1 millimeter. It only knows 1 unit. Dimensioning and scaling is how things appear as 1 inch or 1 millimeter. If you make something 1 unit wide (1 inch) and then alter the dimensioning to show 25.4 millimeters, the object is still 1 unit wide. On the surface it is millimeters but in "reality" it may be. When things are edited, be careful of this "discrepency". Good luck.

"Everybody is ignorant, only on different subjects." — Will Rogers
 
Yes, it needs to be scaled. If you draw a line 1" long (which is 1 unit) and then you change your units to mm, now you have a line that is 1mm long (still 1 unit). It needs to be scaled up to be the proper 25.4mm.
Borgunit had it right from the beginning.
Everyone else needs to try some experimenting on their own.
 
After doing some testing of my own in ADT 2007, I have discovered it will automatically scale existing objects for you if you have it turned on to do so. As soon as I changed units, a warning box comes up saying that existing objects need to be scaled, and has some options you can check. I know one of the main differences here is that in the past, Autocad didn't actually have a MM unit, but rather just decimal. In ADT you can specify in, ft, mm, etc. I don't remember if past version of ADT had this or not.

Regardless, the information is still correct, the objects need to be scaled, whether or not it is done manually or automatically by Autocad.
 
People,

Mauro did not say anything about scaling a drawing.
He mentioned how to convert from inches to millimeters.

That is it. To convert from one unit to another or
even add a unit all you have to do is go to your
dimstyles or setvar's.

Don't make a ten second job a five hour job.
1" = 25.4mm. 1 unit is not 1" or 1 mm people basic
math

Here's the process:
Dimstyles
Primary Units
Alternate units

Hit ok, your done.

I do this all the time converting drawings for people
overseas it takes 10 seconds or less if your have
your templates setup properly.

Andy
 
It's all fine and dandy to change the dimstyle to a different unit, but when you list that 1" line, it's going to tell you it's a 1" line, even if your dimension says 25.4mm. In order to have the drawing diplay the correct units, you must change the units to decimal. Once you change the units to decimal, you now have a line that is 1.0 long, which would imply that it is 1mm long if you are drawing in mm. You have to scale the line up 25.4 times for it to display as 25.4 units. 1 unit is 1 unit - it could be a mm it could be a mile, it just depends on what you are wanting to show. The help file even tells you this. You have to decide what unit of measurement your unit is going to be.

What you are describing is simply showing alternate units in the dimensions. He wants to convert the exist drawing from inches to mm, not just show alternate mm in his dimensions. The only way to convert the drawing is to change the units of the drawing from architectural to decimal. Otherwise how would you draw something that is 70mm long? If you haven't changed the drawing units, and you draw a line with a length of 70, its going to be 70 inches. How are you going to draw it as 70mm? I guess you could calculate how many inches a 70mm line is, and draw it like that, but that's just dumb, and a lot of work.

If you go into the dimstyle, and set the primary units to decimal, all of the dimension will be wrong unless you change the drawings units and scale the drawing. If you notice on the alternate units tab there is a multiplier in there for the alternate units. It's not magically changing everything, it's multiplying the current unit by 25.4 in order to display it as a mm.
 
Here you go, straight from Autocad's help file. it's centimeters, but it's the same comcept.


To convert a drawing from inches to centimeters

From the Modify menu, choose Scale.
At the Select Objects prompt, enter all.
All objects in the drawing are selected for scaling.

Enter a base point of *0,0.
Scaling will be relative to the world coordinate system origin and the location of the drawing origin will remain at the WCS origin.

Enter a scale factor of 2.54 (there are 2.54 centimeters per inch).
All objects in the drawing are now 2.54 times larger, corresponding to the equivalent distance in centimeters.
 
I have found that the best way to change from standard to metric is just to scale the drawing by 25.4. Its better than messing around with other ways, its simple its easy and its quick. that wound make it the best way.

 
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