PDF to DWG Scaling Problem

[Bobzy20]

Hi, I have converted a PDF to DWG and the scale is out, what's the best way to scale it back to its original size?

 

Scale by Reference? This option works ok but no measurement seems to be spot on apart from the item you used for the scale reference.

 

I used the program 'Any PDF to DWG Converter' and the drawing scale in the title block is 1:50.

 

Any ideas?

[emwhite]

Why are you trying to scale it back down? Why not print it back to a PDF and set the scale that way?

[Bobzy20]

Hi, I was looking to scale the drawing back to its original size so I could add to the drawing.

[DANIEL]

you need a hard dimension, something you know is a specific size on the drawing, for instant, theres a tank on the site plan that you know has a diameter of 20 feet, once you get that number go take a distanceof that tank in your new dwg and divide it by the number it needs to be to get the factor and scale it up by that factor, or invert the process should its scale be larger than the number.

[emwhite]

Hi, I was looking to scale the drawing back to its original size so I could add to the drawing.

 

I misread and thought you had scaled it up already and wanted to scale it back down.

 

you need a hard dimension, something you know is a specific size on the drawing, for instant, theres a tank on the site plan that you know has a diameter of 20 feet, once you get that number go take a distanceof that tank in your new dwg and divide it by the number it needs to be to get the factor and scale it up by that factor, or invert the process should its scale be larger than the number.

 

This is what I would recommend as well.

[Bobzy20]

Thanks for all the answers. Ok there is a measurement I know which should be 215mm but at the moment its 0.4056mm.

The drawing scale in the title block is 1:50

 

Can somebody write down what I need to do please?

[DANIEL]

ignore the title block, if the object is actually suppose to be 215mm all you need to do is divide 215 by .4056 to get a factor of 530.0788955, thats how much you need to scale it up by, you may have to do it a couple of time to weed out any minute rounding that takes place during the scaling. you should then be 1:1 in autocad.

[Mike_Taylor]

scale factor = d/ds

d= actual distance

ds=scaled distance

 

215/0.4056=~530.08

 

You can actually enter the equation in when asked for a scale reference. I dont know about newer version of CAD, but 2006 requires whole numbers, so you can simply puit in 2150000/4056

[Mike_Taylor]

Or as mentined use the reference scale

 

Simply start scaling as you normally would, select a base point. Afterwards type "r" for reference,. It will ask for a length which you can measure (in your case it would be .4056). Next it will ask for a new length and simply type in your 215.

 

Both will acheive the same thing in the end, but the latter is prefered.

[emwhite]

Using reference during the Scale would be the most ideal as far as accuracy is concerned and no worries about transposing a number by accident.

[Bobzy20]

Thanks for all your answers. My measurement is now 214.9764, I guess it will never be spot on?

[Mike_Taylor]

It won't, but you can always scale a 2nd time if need be.

[DANIEL]

It won't, but you can always scale a 2nd time if need be.

 

as Mike said, a second time will get you pretty close, the bigger the factor the more likely you'll have to got through the process a second time, I've had to do 3 times even on occasion.

[Bobzy20]

Cheers guys, I will try it a second time and let you know.