How to scale a scanned drawing and convert imperial to metric

[RobertB]

Dear all, 

 

I'd really like some help scaling a drawing properly from imperial units to metric. I have scanned an old architectural drawing with scale 1/4":1' and want to convert this to a metric scale 1:100. I feel like this should be really simple and yet alas I am stumped. So far, I have imported the drawing into a design layer as the original pdf scan @1:1. How do I get this to 1:100 please?

 

Any information will be gratefully received. 

 

Kind Regards, 

 

Rob 

[michaelk]

3 methods:

 

If the pdf is of a good scan and not a pdf that started as a scan, turned into a pdf, got put in a word document where it was squeezed left and right to make it fit and emailed to somebodies nice aunt who somehow opened it in Lotus 123 and saved it again as a pdf…

 

 

1.  The easiest way is to find some existing dimensions on the plan and use Modify>Scale Objects…>Symmetric By Distance.

 

2.  What will probably get you close is this:

 

Create a design layer and set the scale of that layer to 1/4" = 1'-0" (1:48).

Import the PDF.

Change the design layer scale to 1:100.

 

3.  From your 1:1 design layer you should be able to Modify > Scale :  Symmetric X,Y,Z factor  48 

 

In a 1:1 layer scaling it up by 48 makes it life size.  Then change the layer scale to 1:100

 

[Mitchell (the other one)]

I do this a fair amount and use michael's first method:

- review the PDF to see if you can determine the scale, 

- set your design layer scale to match,

- import the pdf

- use Modify > Scale Objects > Symmetric by Distance, then measure a known dimension on the PDF, then enter the known dimension,

- after the PDF scales, measure several other known dimensions to check the result, it is not unusual to have the horizontal dimensions correct but vertical are slightly off,

- if the dimensions are correct in one orientation, you could work out how much they are off in the other and use Asymmetric scaling to correct but that depends on the importance of the PDF to the project, 

- once the scaled PDF is where you want it, change the scale of the design layer.

[Matt Overton]

Just remember if the FIle is in Metric you can type the imperial dimension in the scaling fields and Vectorworks will calculate the conversion for you*!

 

*In field calculation and conversion is still the greatest underrated feature of the program.