Inches and meters

[bulletrick]

I am using AutoCAD 2000.

What is the use of the English and Metric system units when we make a new file?

I did something like this to check the difference:

I created two drawing file: one English, one Metric.

I created one line each drawing both 3 units each.

I copied one line from the English and pasted it on the Metric. The lines have the same length!

One unit of Inches are shorter than one unit of meters, right? :unsure:

[aledtaylor]

I’ve imported a scanned image into a metric drawing and it came in at the correct size, I've never tried this using an imperial drawing though (we're all metric here).

[bulletrick]

imperial drawing

Nice term. :D

[dbroada]

have you tried it with dashed lines? We draw in units, not in inches or mm so in both drawings the line was 3 units long. The difference should come in the other things you set up. You should use lines from acad.lin for imperial and from acadiso.lin for metric as their definitions have approx a factor of 25 difference. Likewise your dim style sholud have text about 3 units high in metric or 0.18" high in imperial.

[hazardman]

the units in autocad are simply that units...it does not distinguish between "imperial" or "metric"--you only tell autocad what 1 unit is, inches, mm etc...

the only real setting is the measurement setvar for "english" and "metric" setting which indirectly affect the hatch pattern scale...if set to a value of 1 a hatch scale of 1 for conc block will make it 200 units verses set to 0 will make it 16...

[thalon]

I believe it starts having an impact more in 2006, although it can still be used in the earlier versions.

If you have the units set to mm in a drawing and bring in a block that has been defined and set to inches, autocad can see this and automatically scale the block appropiately the the world of mm.

In 2006 (so my colegues tell me) this setting is used automatically when bringing in xrefs. so if two people create drawings and one didn't know theres was started using mm and the other using inches, but both draw as if it was set up in inches. When these two drawings are xrefed together the scale will appear wrong for one of them.

Just another useful feature I didn't know I wanted :unsure:

[bulletrick]

So what are the units I am setting for? I mean, what does AutoCAD 2000 do if I will set it to English or Metric?

[hazardman]

what does AutoCAD 2000 do if I will set it to English or Metric?

refers to the alternate pattern and linetype files....

if measurement is set to 0 (english) it will use acad.pat for hatches and acad.lin for linetypes...

if measurement is set to 1 (metric) it will use acadiso.pat for hatches and acadiso.lin for linetypes...these two files are scaled up 25.4 which is a conversion factor of which 1" = 25.4mm...

in general drawings are produced in either inches or millimetres...being canadian we're still stuck between the two system...usually residential stuff is imperial and commercial is metric...so if i have drawn a block in metric and insert it in an imperial drawing i simply scale it down by 0.03937 (which is 1/25.4)...if the other way iscale it up by 25.4...

i know this seem backwards but that how i deal with it :wink: ...

[dbroada]

that's what I tried to say several posts ago :D

I think 2006 will suit you (hazardman) in that the blocks come in pre-scaled depending on the set units if you are in mixed units but it's a real pain when you are totally metric but some blocks have been saved in the "wrong" units.

[hazardman]

yes, that feature in 2006 seem handy, but not every one is on that version yet... :wink:

[aledtaylor]

Using both imperial and metric units seems to me to be a recipe for disaster i.e. space craft crashing into Mars.

All companies should decide which it uses, and in many cases I'm sure, it will take a management decision to resolve the issue.

Here in Europe we tend to fall in line with the scientific standard of metric units.

[dbroada]

Using both imperial and metric units seems to me to be a recipe for disaster i.e. space craft crashing into Mars.

All companies should decide which it uses, and in many cases I'm sure, it will take a management decision to resolve the issue.

Here in Europe we tend to fall in line with the scientific standard of metric units.
true but it's not always possible. Much of our equipment comes from US vendors so we get drawings from the states. Also we have a branch over there who (naturally) still draw in imperial. I know we could take their drawings and scale them and resave them but it is far easier to just use the supplied drawings as blocks and scale them locally.