Any CAD Operators?

Matutu · 13 May 2012 at 18:25

Hey Guys,

I do a lot of mechanical engineering works, mainly in building services.

I am doing a lot of quotations at the moment, now to enable me to do this I receive a lot of drawings to price, these I have to print to scale off....

Normally the item i need to measure off is quite small, but I still need to print the full drawing to enable this to be to scale.

Now some of these jobs I don't win so therefore they go in the bin and A - Not cost effective, B - Not environmentally sound.

So is there a way of measure items on a PDF drawing on the screen? For example looking at a A1 drawing on the screen and clicking point A then clicking point B and finding out these is 3metre? at a 1:50 scale etc.

Thanks.

Jock · 13 May 2012 at 18:33

In the past all I've done is Bring the PDF into cad and scale appropriately, then use the measure tool. Though obviously depends if you have cad or not.

pepsilol · 13 May 2012 at 19:23

Can I jump in on this thread.

I have this little machined component that I need CAD drawn so I can email the drawings to people. It looks like it would require someone pretty familiar with the software as it isn't a straight forward shape!

Email in trust.

Emphacy · 13 May 2012 at 19:54

There's unfortunately not a lot you can do if it's in a PDF format + Didn't know you could import PDF into a CAD program, atleast you can't do it with AutoCAD anyway.
Also Pepsilol, how difficult is the machine component you need designing? Does it include dimensions? You want it in 3D/Orthographic?

Danny UK · 13 May 2012 at 20:05

Could you ask for the drawings in DWF or DWG format? Autodesk makes free software (Design Review) which allows you to open these formats and you can take measurements.

ash_scotland88 · 13 May 2012 at 20:13

Emphacy said:
There's unfortunately not a lot you can do if it's in a PDF format + Didn't know you could import PDF into a CAD program, atleast you can't do it with AutoCAD anyway.
Also Pepsilol, how difficult is the machine component you need designing? Does it include dimensions? You want it in 3D/Orthographic?

Might be something along the lines of applying the image to a plane and working off that, atleast you can do similar things with image files in 3ds max.

Matutu · 14 May 2012 at 08:16

That's a shame thought there might be a measuring tool for PDF files. Would save so much paper and time!

the_r_sole · 14 May 2012 at 09:08

export pdf as image, import into autocad, measure away!

also in acrobat pro - under tool>analysis>measuring tool (you'll have to change the units to mm and the snaps are pretty bad)

Marky · 14 May 2012 at 09:11

We have a similar problem where I work. I'm an electrical engineer, but during my apprenticeship I also trained on CAD to complete CAD drawings for our company.

Most times we get a .DWG file sent to us to use but sometimes they send a PDF. I normally just ask them to either send a .DWG file or send me a PDF that is scaled correctly (Because often people will use A1 and convert to PDF which is no good). Or you could ask them to send you a PDF with dimensions on.

the_r_sole said:
export pdf as image, import into autocad, measure away!

also in acrobat pro - under tool>analysis>measuring tool (you'll have to change the units to mm and the snaps are pretty bad)

This may not work. Often when people convert a drawing into a PDF it's in A1 in the drawing program and converting it in a PDF won't convert it into a A1 PDF. So it is shrunk incorrectly, therefore not giving you a drawing that is in scale.

the_r_sole · 14 May 2012 at 09:16

Marky said:
This may not work. Often when people convert a drawing into a PDF it's in A1 in the drawing program and converting it in a PDF won't convert it into a A1 PDF. So it is shrunk incorrectly, therefore not giving you a drawing that is in scale.

if you import the image into autocad all you have to do is scale the image correctly back to 1:1 the scaling of the pdf doesn't matter at all

rG-tom · 14 May 2012 at 09:17

I work for an engineering company, and whenever we send out drawings for subcon machining we always ensure that any dimensions that need knowing are labelled. One of the first lessons i was taught was never measure dimensions by hand from pdf drawings!

I'd be asking for dxf/dwgs or labelled drawings, that's p. shocking IMO :s

rG-tom · 14 May 2012 at 09:19

the_r_sole said:
if you import the image into autocad all you have to do is scale the image correctly back to 1:1 the scaling of the pdf doesn't matter at all

Not correct. If the image is "printed" to PDF at A1, if you import into autocad and scale 1:1, it will be scaled the same as if you printed it, at a A1. If the drawing was meant to be printed at A3 to be 1:1, then you'll have dimensions that are 4x too big (or whatever the ratio of a3 to a1 is). If the pdf hasn't been scaled right, you're screwed unless there is a dimension that you can use as a point of reference.

realBabelfish · 14 May 2012 at 09:22

we use some free software called bravareader to scale from PDFs.

you need to know 1 dimension though as it uses that to scale from (PDF cant hold scales)

better to get the DWG and use one of autodesk's free readers (DWG trueview). you can then get the proper dims. not everyone sends DWGs though.

realBabelfish · 14 May 2012 at 09:24

rG-tom said:
Not correct. If the image is "printed" to PDF at A1, if you import into autocad and scale 1:1, it will be scaled the same as if you printed it, at a A1. If the drawing was meant to be printed at A3 to be 1:1, then you'll have dimensions that are 4x too big (or whatever the ratio of a3 to a1 is). If the pdf hasn't been scaled right, you're screwed unless there is a dimension that you can use as a point of reference.

we get a lot that say A1 on the drawing but the pdf is A3, so beware of that.

i work for a flooring company and we need to scale lots of drawings.

Marky · 14 May 2012 at 09:25

the_r_sole said:
if you import the image into autocad all you have to do is scale the image correctly back to 1:1 the scaling of the pdf doesn't matter at all

No that's not right. What I'm saying is if the drawing is A1 and you convert it to PDF, it will not be A1. It'll be shrunk down - not to scale - to A4. So no dimensions on the PDF will be correct. Scaling the image to 1:1 will just give you a A4 drawing that isn't to scale.

the_r_sole · 14 May 2012 at 09:26

rG-tom said:
Not correct. If the image is "printed" to PDF at A1, if you import into autocad and scale 1:1, it will be scaled the same as if you printed it, at a A1. If the drawing was meant to be printed at A3 to be 1:1, then you'll have dimensions that are 4x too big (or whatever the ratio of a3 to a1 is). If the pdf hasn't been scaled right, you're screwed unless there is a dimension that you can use as a point of reference.

import to autocad THEN scale back to 1:1, there does have to be something to reference (which there usually is)
But if you are trying to scale drawings from a company that can't even get their prints at the right size, I would serioulsy worry about the accuracy of the drawings

Marky · 14 May 2012 at 09:29

the_r_sole said:
import to autocad THEN scale back to 1:1, there does have to be something to reference (which there usually is)
But if you are trying to scale drawings from a company that can't even get their prints at the right size, I would serioulsy worry about the accuracy of the drawings

As I mentioned, scaling the image to 1:1 will just give you a A4 drawing that isn't to scale.

the_r_sole · 14 May 2012 at 09:31

Marky said:
As I mentioned, scaling the image to 1:1 will just give you a A4 drawing that isn't to scale.

import the image into autocad, select it, scale it to 1:1 by using a reference dimension
this has nothing to do with how it was printed

jumpy · 14 May 2012 at 09:34

Evidently whoever is plotting to PDF from CAD is doing it wrong

the_r_sole is correct.
If there's a dimension in the PDF or a known distance, you can take an image of the pdf and import it back into CAD and scale off the dimension from a base point to the known dimension at 1:1 in the model space. - ie draw the dimm in model space @ 1:1, import pdf image then scale that from a base point to the dimension you've previously drawn.
Tbh it's a dreadful way of bodging a scaled drawing, but if it's only for a quick reference you might get away with it. Failing that, email for a better drawing to be sent.

If there's no 'known distance' in the pdf with which to scale off, then you're stuffed.

Marky · 14 May 2012 at 09:36

the_r_sole said:
import the image into autocad, select it, scale it to 1:1 by using a reference dimension
this has nothing to do with how it was printed

Oh right now I understand - You're using a point of reference. I still don't think it's very accurate though (But I am pretty OCD on accuracy when I draw

). I would certainly be asking for either a PDF with dimensions or an actual .DWG file.