As built drawings from PDF scan

[Anonymous]

Hello, I'm attempting to create Autocad drawings from a PDF of scanned hand-drawn documents. I believe the layout is simple enough to do without conversion software. I just need to insert my PDFs at the correct scale to trace over or get a starting reference point. The drawings are marked at 1/4"=1' but I'm not sure what size paper they were done on and there are no envelope dimensions, or really any dimensions at all. I could assume doorways are 3' wide, but other than that I don't have a good starting point. Any suggestions?

[Alfred.NESWADBA · Accepted solution]

Hi,

>> I just need to insert my PDFs at the correct scale to trace over

Use command _PDFATTACH to display the pdf-content inside AutoCAD.

Assuming you have a dimension in the pdf-content you can then use command _SCALE with option _REFERENCE to scale the pdf according to the 2 points dimensioned in the pdf and the real value this vector should have.

- alfred -

[Anonymous]

I've essentially done this based on the door frame width. I suppose this may be more of an architectural question, but is there a more accurate reference point besides a door frame that I'm not thinking of?

[GrantsPirate · Accepted solution]

Usually in this case the door way opening is the way to go.  Draw a line across the door opening, then using the scale command you can pick one end of the line, use the Reference option and pick both ends of the line, then enter 3'.  Measure the opening again and if it is still off then go again until you have it dialed in close enough.  Scanned drawings will not ever be exact but I guess good enough since you have no dimensions to go from.

[ChicagoLooper]

Door openings can vary. If that's all you have, then use caution. If this is an as-built then use your resources to research the as-built. As-builts can be used to determine envelope dimensions and envelope dims trump door openings because exterior wall lengths are more reliable than distances close together, like door openings.  Only takes 1 to 2 minutes to research.