Autocad to PDF plans - measurement scale not transferring

[Anonymous]

Does anyone know what would cause the scale of Autocad plans to not transfer during the conversion to PDF?

Here's the scoop: I work for a hydronic radiant contractor. I don't use Autocad myself. I receive plans, created in Autocad and converted to PDF. Using Adobe Acrobat Pro, I take 2D measurements of the floor plans (excluding certain areas, depending on client preference and product/installation type). Normally, this is as simple as grabbing the measurement tool, setting the scale embedded in the plans, and grabbing measurements. The designers here use Vector Works but, for proposal take-offs, Adobe has held up just fine over the years. Lately, however, I have been receiving plans in which I cannot take an accurate measurement. I have received these plans from various contractors/architects/clients. There is no discernable pattern as far as origin. It is not every plan. Most of the PDF plans I receive measure just fine. But the ones that don't are a real hassle.

• Example: the scale is 1/4" = 1' (as written on the plans). Say a simple length is marked on the plans as 20'. The Adobe measuring tool reads this as some odd number like 4.345' or 1.376'. 

I have gone through all the settings with Adobe support. I also had Adobe techs remote in and investigate my program for any glitches and they find that, as far as their program is concerned, it is taking the measurement as it should. They looked at the proportion of the measurements and found no issue (as did I). They posited that the plans did not carry a scale of their own as they ought to.

I realize this is an Autocad forum so I don't expect anyone to speak to the Adobe side of it, unless you feel so inclined. Any and all thoughts are welcome here. Further, if I am correct in that there is some special method to ensure Autocad transfers the scale to Adobe PDF, would anyone be willing to write out those steps or direct me to an article? This would be useful when speaking to my clients about this. Thanks.

[rkmcswain]

Generally speaking, a given PDF should be "to scale", meaning that Acrobat, or Bluebeam, or whatever PDF app you have, should be able to give you accurate measurements.

But, it's not impossible to generate a PDF (or any print for that matter) that is not to scale. Just because it says 1/4" = 1'-0" does not mean the CAD operator didn't mistakenly, carelessly, or even purposely, printed it not to scale. Floating viewports, if not locked, can easily be zoomed 'out of scale' and this could perhaps go unnoticed. Not saying it's common, but possible.

If you had the .DWG file, this would be easy to find.  This may be of some assistance.

[nrz13]

I'm not sure why that would be coming out that way, but maybe if a few people post their PDFs here we can discover a pattern.  I've attached some sample PDFs that were created with different drivers.  Do any of them not scale correctly?

The attachment includes:
● PDF created using AutoCAD's built-in PDF driver (with a variant with changed default opening settings on the PDF)
● PDF created using AutoCAD's built-in DWF to PDF driver
● PDF created using Microsoft's built-in (to Windows 10) Print to PDF driver
● PDF created using Foxit PhantomPDF's driver
● Source AutoCAD DWG file (for others to create tests from if they want)

The typical solution for things not being to scale is unchecking "Fit to paper" in the Plot dialog, but I doubt that is the issue here since it is coming from multiple sources.

[Anonymous]

Thank you! This gives me a much better insight into what my clients are doing before sending these plans.

[Anonymous]

Wow. That was super helpful. I went through and tested each of those files and they all measured properly. This leads me to believe that whoever is converting these plans to PDF is not locking the Scale Viewport (as the above user mentioned).

[Anonymous]

You mention that if I had the .DWG file, it would be easy to find the actual scale. Can you expound on how I would do that? Would I use the DWG Viewer? 

[maratovich]

If A2 PDF was sent to you, but you know that it should be A1, then you can increase the PDF (scale the PDF).

[Anonymous]

Could you clarify this? I'm unfamiliar with A1 and A2 PDF

[maratovich]

---

@Anonymous  написал (-а):
Could you clarify this? I'm unfamiliar with A1 and A2 PDF

---

---

Paper size 

International System of Units 

International Organization for Standardization 

[FoxOnsite]

Running into this same problem.  

Regulating body says they can't use their "adobe PDF  tool"

From what I can tell is that printing from paper space with a correctly scaled view port (ex 1"=20')  makes it kind of wonky? I think if it printed from Model space it would be okay but we do all our print from paperspace? 

So I am unsure how to solve this still. 

[pendean]

@FoxOnsite Wonky? why would that be please? Jut as many AutoCAD users plot from Layout that probably do not, no one is outputting "wonky' PDFs at any time.