Convert from Metric to Imperial

Hi All,

Can anyone tell me if its possible to convert a drawing done in metric measurement to imperial measurement, and visa-versa?

Regards,

John

Wouldn't you just change the units and scale by 3.2808?

A common practice, imperial to metric, metric to imperial.

"How to convert a drawing from inches to centimeters (or vice versa)?

First of all - an AutoCAD drawing in the modelspace is unitless. A drawing unit can be anything you wish. A square of 10x10 units can be 10mm, 10m, 10", 10 feets, whatever. The real physical units are required only when you want to represent the drawing model for the real world - for dimensioning, plotting (plot scale), paperspace and annotation functions.

But if you really want to scale your drawing from inches to milimeters, centimeters, meters - or vice versa - e.g. from centimeters to inches, you can use the SCALE command.

When going e.g. from inches to centimers, you have to scale up your drawing 2.54x. Run the SCALE command, select All objects, specify 0,0 (global) as the reference point and enter 2.54 as the scale factor.

You can prepare a menu macro button to perform this conversion operation automatically (menu macros use ";" instead of Enter) - some examples:

[inches->CM]^C^C_SCALE;_All;;*0,0;2.54;

[inches->MM]^C^C_SCALE;_All;;*0,0;25.4;

[CM->Inches]^C^C_SCALE;_All;;*0,0;0.3937;"

Thanks for your help fellows, but I think I explained myself poorly. What I want to do is convert the drawing from metric measurements to imperial measurements and visa-versa. The drawing is actual size. I want to be able to see the measurements in metric or imperial. Can I change the drawing from one to the other without effecting the drawing itself?

John

Couldn't you just set up two different dimstyles? One metric, one imperial?

Format>Dimension Style...

I thought that Dimstyles effect the way dims are displayed, such as arrows, placement etc, but it does not determine the measurement system itself.

I have done this sort of thing before using the ALTERNATE UNITS setting in the dimstyle so that dimensions show the metric and the imperial on the same dimension.

Attached is an example for you to look at.

Club Proposal 11 aug 2009.dwg

This is a great way to do things. Many thanks for this one. Although it is a good way to display measurements it does not tell me if a drawings can be converted. But thanks anyway.

I can't open Nuke's drawing but I set up either 2 dim styles or a single dimstyle with alternate units enabled. Depending what your base units are you need a multiplication scale of either 25.4:1 or its reciprocal. Have a dig in the dimstyle dialogue box and you will encounter the measurement scale entries.

This is a great way to do things. Many thanks for this one. Although it is a good way to display measurements it does not tell me if a drawings can be converted. But thanks anyway.

Not sure what you mean by converted.

A line is as long as it is, wether you dimension it in metric or imperial it is still the same length.

Dual-dimensioned drawings have been in use longer than you have been breathing and that's back before CAD was even in widespread use. They do not have to be "converted".

On the other hand, should you receive a metric drawing but want to use imperial units, or send someone a drawing and they use metric then the drawings will have to be scaled accordingly. But they are not "converted". Pagans are converted.

Another way to think of it is that if the drawing is done at 1:1 by definition the drawing does not have to be converted. A line that is as long as your finger in the real world is as long as your finger in the drawing. The only thing that you need to change is how the drawing is dimensioned - via dimstyles. You set up a dimstyle for metric in milimeters, one for metric in centimeters, another for meters, for imperial feet, inches, fingers, cubits. Heck, set one up for furcansee's (that way as fur (far) as you can see) best used for large Civil drawings.

Once you have the dimstyles set up you simply select all the dimensions and assign them to a new dimstyle. POOF! Your drawing is now "converted".

Glen

Another way to think of it is that if the drawing is done at 1:1 by definition the drawing does not have to be converted. A line that is as long as your finger in the real world is as long as your finger in the drawing. The only thing that you need to change is how the drawing is dimensioned - via dimstyles. You set up a dimstyle for metric in milimeters, one for metric in centimeters, another for meters, for imperial feet, inches, fingers, cubits. Heck, set one up for furcansee's (that way as fur (far) as you can see) best used for large Civil drawings.

 

Once you have the dimstyles set up you simply select all the dimensions and assign them to a new dimstyle. POOF! Your drawing is now "converted".

 

Glen

To use your example you set up your units to be "FINGERS" so you draw your finger at 1:1, it is one finger unit long. Having now drawn it 1 unit long and apply your imperial dim style it will now measure 1" long. Change dimstyle to metric and it now measures 1mm.

However if you set your multiplication factor in the dimstyle you can let the dimensions do the sums without scaling the drawing.

I still think it is much simpler just to use alternate units as previously suggested. When you do enable Display alternate units there is a place to input Multiplier for alt. units. Mine is preset for 25.4 (any guesses what that is referring to?).

... you do need a multiplication value in there somewhere.

 

To use your example you set up your units to be "FINGERS" so you draw your finger at 1:1, it is one finger unit long. Having now drawn it 1 unit long and apply your imperial dim style it will now measure 1" long. Change dimstyle to metric and it now measures 1mm.

 

However if you set your multiplication factor in the dimstyle you can let the dimensions do the sums without scaling the drawing.

Dbroada, you are correct, I was not clear enough in my explanation. I imagine the drawing space as a virtual world. By setting it to a 1:1 scale to the real world, stuff in the drawing space is exactly the same size as it is out here. But of course to do that, you have to tell AutoCAD what size units you are using to input it. So having made that decision, you must then use the multipliers and prefix/sufixes in the dimstyles to convert from what you have told AutoCAD you are drawing in to the units that you want displayed on a dimension line. So one finger is 4.0 inches or 101.6 mm or whatever. I've seen dimensions in drawings that are displayed in CMU's. It was easy for the guy in the field to count blocks in the foundation to locate things - so that's what was used.

Glen

I think that what you are looking for may be LINEAR DIMENSION SCALE this will multiply the value of dimension text without changing the size of the text, gaps and extensions, or arrows/ticks.

Gentlemen, thank you for your help and the information you have given. I now have a much better ideal of how to go about changing a drawing from one type of unit to another, and a good work around using dual-dimensioned drawings. Thank you for your help.

Gentlemen, thank you for your help and the information you have given. I now have a much better ideal of how to go about changing a drawing from one type of unit to another, and a good work around using dual-dimensioned drawings. Thank you for your help.

 

I still don't know what that means. Anyone?

I still don't know what that means. Anyone?

traditionally drawings were "unitless" where the draughtsman decided what a unit represents, could be mm, inches, lightyears or even fingers. Now you can choose what 1 unit represents using the UNITS command.

Just changing units doesn't convert the drawing which is what a lot of people expect.

I'm not sure but have assumed the OP meant between metric and imperial.

 

traditionally drawings were "unitless" where the draughtsman decided what a unit represents, could be mm, inches, lightyears or even fingers. Now you can choose what 1 unit represents using the UNITS command.

 

Just changing units doesn't convert the drawing which is what a lot of people expect.

Okay. I guess that makes sense. Thanks.