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Large drawing set - raster to vector - AutoCAD - advice needed 2

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USAeng

Mechanical
Jun 6, 2010
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Hey all,

I have very large full set of drawings of our plant that are just scanned from 1983. I have been tasked with converting the old PDF to AutoCAD. We just got CAD software here - I used Solidworks for a year at my last job so I'm a beginner but am not afraid to put in the work. I do have some familiarity with the program.

I feel like I might be in over my head at the moment... I just started looking at it and the task seems daunting when looking at this method (see LINK below) for so many large drawings - but I usually can do anything I put my mind to.

Link

The only other idea is I can suggest subbing this out to an experienced firm. What is the typical method used to accomplish this task?

Thanks
 
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To be fair, I haven't used AutoCAD's raster to vector function; it might be orders of magnitude better than the several third party raster to vector converters that I have used.

If it were that good, it would still be crap.

PDFs from scanned drawings typically come in with a bazillion unrelated short line segments, some of which can be interpreted by a human as just a light line from a dirty original, or the dirt, and some of which can be interpreted by a human as the line element atomic decomposition of alphanumeric characters. Computers are basically hopeless for this sort of stuff.

You might farm it out for redraw to a low cost labor company. You can find much discussion about that on this site. I probably wouldn't.


I would be inclined to redraw the whole set myself.
... but NOT in AutoCAD. I'd model it in Solidworks, then export .DWG files using SW. Maybe you can rent a SW seat for a while.

I have ~30 years of experience with bare AutoCAD, and I'm not the slowest drafter I know.

I'm _way_ quicker to usable drawings using Solidworks, with my mere 3 years of OJT.

If you want _pretty_ drawings, or want them in a format that doesn't _look_ like a SW drawing, I'd probably massage them in AutoCAD. I really hate the DWG editor in SW, mostly because it's always trying to help me by doing something automatically, but it's never doing what I want done at that time.

{
I hate all software that falls short of its potential.
... and all software does fall short of its potential.
}



Mike Halloran
Pembroke Pines, FL, USA
 
I've had to do this kind of tedious work, but only one drawing at a time, not a whole plant worth of them.
Are these drawings needed for plant upgrades, and hence will be revised / redrawn for ongoing use?
Or will the resulting drawings just be printed ad infinitum?
I was once faced with old paper drawings that needed new parts lists. It easiest to scan them, and use photoshop to cut out the old parts lists, then attach the image into AutoCAD to put in the new parts list. Only the PL was generated by ACAD, and the image scan constitutes the rest of the drawing. Prints nice and all up to date.


STF
 
PDF can be downloaded into ACAD from the Insert Pull down menu and select OLE. If you really have a raster file such as JPEG, then go back to Insert then select either Image Manager or Raster Image. Remember the file is an attachment to ACAD, therefore, make sure that the directory path is available from ACAD otherwise,you'll get an outline of the drawing without the PDF or raster image.
 
I have used the AutoCAD raster editor a long time ago. The raster format is a bit map the more resolution the easier it is to work with. The text can be virtually illegible if it is too coarse. Typically you work on the drawing only as needed. To do a change you only convert portions of the drawing to a vector format.

Character recognition to convert all of the text is more miss than hit in my experience, and selecting a font that matches the existing lettering is tough. The drawings can look pretty crappy if you have different fonts even if the line work looks good.
 
USAeng-

WAY back in time, we had an ACAD plugin program that would open a raster scan file into ACAD, and allow you to "edit" the raster document as if it was native ACAD. No, it WAS NOT vector, it remained raster, its just that the plugin had the interesting characteristic of operating VERY similarly to ACAD, and the result was a "hybrid" kind of file, that had changes, new input, text etc (stuff you'd done after loading the file) as native ACAD entities, in combination with the underlying raster image. Wipeouts, dimensions, text, tables, etc , created in the ACAD became part of the hybrid "file" and, the overall acted as if it was one file, editable in ACAD, and saved as a non-sharable drawing (DWG) - unless the target user also had the plugin . You could even erase (and clean up) raster entities and scan "clutter" This approach eliminated the need to convert from raster to vector, and still gave us "CAD" access to legacy "scanned" drawings.

1. I DO NOT remember the name of the program, SORRY, but I hope I've offered enough clues that someone might recognize the plugin I'm describing or that you might be able to do a search for something like this. We used it for the entire time I was there, and found it very functional. All you had to do was limit access to the folder on the network as a copy of the locked scanned drawings folder, and work with that...

2. I can't even say its still available on the market now, but it may be. Worth looking, if your stack is that big !

PROGECAD has a plugin that they use for this. I think you set it to scan to single mid-lines, as stitched p-lines, and I'm told that he result is usable, but I haven't played with it myself, and I remain doubtful ...

Post back with results- if any - and -

Good luck !

-C.
 
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