How do I set a scale with an imported PDF / JPG?

[pcarbon02]

Hello,

 

I searched though the existing posts on scaling, but I didn't quite find a solution for this one. I want to change the scale, however there is not an existing one (or it is default I guess).

 

I am dealing with a scanned drawing so I imported a PDF via JPG and imported it into AutoCAD (2004 LT). Now I want to get the scaling to reflect the dimensions on this drawing. For instance, I know that the light fixture on the drawing is 4' long. When I use the Dimension -> Aligned function it says it is 0.75 units long. How can I change the scaling to reflect that 0.75 should be 4'?

[ABuckingham]

1) Start the scale command.

 

2) Select the object you want to scale.

 

3) Choose a basepoint - any point will do.

 

4) When it asks for the scale type R for reference.

 

5) Then click the two points that should be 4' but aren't currently.

 

6) Then type in the size you want it to be, in this case 4'

[pcarbon02]

Thank you Buckingham for your help!

 

I created a line the length of the 4' fixture so I have an object to select when the scale command tells me to select an object.

 

I get through almost all of the process, but after I type R for reference it says, "specify reference length " I click one end of the line. It then says "Specify second point" (I click the other end of the line). Then I get a line that is now 5 times as long.

 

Am I missing something?

[ABuckingham]

I created a line the length of the 4' fixture so I have an object to select when the scale command tells me to select an object.

 

Ok, the object you're trying to scale is the inserted image. When you are prompted to select an object, select the image itself. You'll have to click on the boundary.

 

If I were scaling the image, after I chose R for reference, I'd click on the tip of one arrowhead, then the tip of the other, then type 7'. What should happen is the drawing will scale so that the 7' dimensioned is actually 7'.

[Hattye]

I need to scale a pdf without any reference, no measures. The only thing I now it scale is 1/4"=1'-0". How can I scale it to get the real dimensions?

[tombu]

6 hours ago, Hattye said:

I need to scale a pdf without any reference, no measures. The only thing I now it scale is 1/4"=1'-0". How can I scale it to get the real dimensions?

Scale basepoint 0,0 and a scale of 48 (I simply multiplied 4 × 12).

[CyberAngel]

This may be somewhat off topic, but when I have a PDF or DWG that has to match another DWG, I may use the Align command. Find two or three points that correspond to each other. Obviously, if you don't have any such points, you're stuck.

 

Once you start the Align command, pick a point in the unscaled document and then pick the corresponding point in the scaled document. Do the same thing for the second pair of points. You have the option to pick a third pair or to press Enter and proceed.

 

With three points, the document will be scaled. With two points, you have the option to scale or not. The unscaled document is then moved and/or rotated and/or scaled to align your points. You may get something slightly off. In tombu's example, you might get 47.92. Type in 48, check your result, and you're done.

[Cad64]

On 7/3/2019 at 12:12 AM, Hattye said:

I need to scale a pdf without any reference, no measures. The only thing I now it scale is 1/4"=1'-0". How can I scale it to get the real dimensions?

 

How do you know the scale is 1/4"=1'-0"? Is there a scale bar on the pdf? If so, you can use that as reference. But, if it's just text telling you the scale, how do you know the pdf was printed full size? It could have been printed "scaled to fit". Without any reference, you don't really know for sure. I would contact the person who provided the pdf and verify the scale or ask them to put a scale bar on the drawing and send a new pdf.

[SLW210]

Even if it was plotted at the 1/4"=1'-0", the PDFs can be a little off in either or both the xy directions. Best to try and determine the size of some known objects in the PDF and scale by reference. If you make it a block you can scale in both the x and y directions if needed.

[acadesign09]

This simple...Just

1. activate SCALE or SC command 

2. Press Enter

3. Select your PDF object to scale(Note: It is advise to take any available dimension in the PDF)

4. Press enter again

5. Select 2 points( any points from your sample available dimension in step no.3)

6. Then select a 2 POINTS by pressing P command 

 

 

Thats it...enjoy