Scale imperial and mertic

[ben10]

Hi

I have been working in the metric system for ten years now,and now i have a request to change a drawing to Imperial.What I want to know is what is the size differences between 1:100 and 1/4"= 1'-0" scale?Is 1:100 the same as 1/4"=1'-0"?

Can I change the metric plans as is, to feet and inches?, or do I have to scale the plans?

And what is the appropriate Imperial scales for:

-floor plans

-elevations

-details

thanks

Ben

[SuperCAD]

Going from metric to imperial, the scale factor is 0.03937. Going from imperial to metric, the scale factor is 25.4. I believe 1/4" = 1' converts to 1:50.

[ReMark]

No, 1:50 would be roughly equivalent to 1/4"=1'-0". See this: http://academics.triton.edu/faculty/fheitzman/metric.html

 

You could elect to draw using alternate dimensions (showing both) but it might not be acceptable to the company or client you are working for.

 

I typically see floor plans and elevations drawn to 1/4"=1'-0" scale. On rare ocassions I've seen 1/8"=1'-0" used for very large buildings.

 

Details can vary. I've seen 1/2"=1', 3/4"=1', 1 1/2"=1', and even 3"=1'.

[ben10]

Thank you

That makes sense, so all I'll have to do is scale from 1:100 to 1:50 for the floor plans.

Guess I can keep the elevation 1:100 then that would be 1/8"=1'-0"

Thanks again

[ReMark]

1:100 is a rough equivalent of 1/8"=1'-0" so you better take that into account. I guess that would be OK if "close enough" is what you are aiming for. Horseshoes anyone?

[irneb]

Yep, Imperial and metric scales are only roughly equivalent. E.g.:

1/8"=1'-0"
x8 --> 1"=8'=8x12"=96"
--> 1"=96" --> 1:96 ≈ 1:100

Clearly it's close but not exact.

 

There's numerous ways of getting this sorted out. But if your stuff is already drawn in mm, and the imperial representation is not the only thing you want I'd go with the following:

 

Ensure your InsUnits of the original is set to 4 (i.e. Milli Meters). Create a new drawing (usually from ACAD.DWT instead of ACADISO.DWT) and ensure its InsUnits=1 (Inches). Then XRef the original into it - that should automatically scale to suit. Then create your imperial dims, TB and viewports in the new DWG.

 

This way you still have the original metric drawing, but the imperial version links to it.

[ben10]

thank you Irneb

I have done that,but I get an un-edible drawing.

[ReMark]

I have done that,but I get an un-edible drawing.

 

I do not recommend eating drawings. It's bad for the digestive system.

 

Post the drawing file itself and let us have a go at it.

[ben10]

LMAO! un-editable

I would have, but apparently it exceeds the forums attachment file size.

No problem, I'll just add both scales as you have suggested.

Thanks

[ReMark]

Try zipping the drawing file first.

 

Are you going to be doing this type of work often (creating drawings in imperial scale)?

[SuperCAD]

If you don't need to keep a metric version of the drawing, start a new drawing with imperial units and then copy/paste the drawing into the new file and scale everything down to imperial with a scale factor of 0.03937. I do that all the time with MFG drawings that are done in metric units and it works great.

[irneb]

I do not recommend eating drawings. It's bad for the digestive system.

 

Post the drawing file itself and let us have a go at it.

What? You want some take-out?

 

As to the uneditable DWG. It "is" editable, it's just as if it's a block. You could also have simply Inserted & browsed to the DWG, then exploded it. But then the one's not linked to the other, so changes you make in the original won't later reflect in the copy. Basically does the same as SuperCAD's method does - just don't need to know the scale factor.

[ben10]

OK problem solved,thanks again for all the help.

Remark.I don't know,hopefully the US will be converting sooner as your link have stated.(but 1993? I doubt it)

[ccowgill]

I dont see the US converting to anything, we're kind of stubborn that way. but thats just my opinion.

[hazardman]

meanwhile, in the great white north (canada, eh!), we use both systems...typically residential is in imperial and commercial/institutional is metric...

[irneb]

Over here in SA, we use metric nearly 100% of the time. It's just when working on historical buildings where the original drawings were done using Imperial ... but then there's also some strange things where the actual length of a foot altered at some point. So we have Imperial feet, but then also Cape feet. Screws a bit when you're doing calcs

[Tyke]

Can any of the hairy old surveyors remember Chains, Rods, Perches and Poles. We used scales such as two chains to the inch or six iches to the mile.

It makes life so much simpler to work in metric units, it's just a pity some of you guys HAVE to work in imperial or other such units.

[ReMark]

I remember the terms chains and links. But then again, "Dirt", is my younger brother!

 

Sometimes I just crack myself up.

 

I just thought of two more surveying terms I don't hear that often: furlong and hectare.

[irneb]

Actually Hectare is the metric measurement to land areas. It's basically 100m X 100m = 10 000m² = 1ha. I hear that a lot more than I do Acres:lol: ... Though not as much as I hear square meters (m²) though, but that might be industry specific.