Plan dimensions

[Vijay]

Hi,

 

Is there any easy to use software that will allow me to get accurate dimensions off plans from either PDF or CAD files? Basically I want to highlight 2 points and get an accurate dimension.

 

Cheers

 

Vijay

[IanR]

The free acrobat reader from Adobe has a measure option under analyse. You just need to select it then right mouse click and set the scale to what the drawing is. 

[TerryE]

@Vijay, I use Draftsight, but it can run like a dog if you use it on a typical laptop.  AFAIK, it really needs a PC with decent CUDA graphics card to get responsive performance.  Also try the VariCAD Viewer. This will open DRW files and you can zip around them, take measurements and print off extracts fast.

 

Be aware that it also the creating package renders the PDF file.  This might be using vector graphics but many generate diagrams at a give BPI for the target page size; so if you zoom in then drawing starts to look pixelated.  Hopefully your diagrams include a scale rule to validate scaling, but as Sensus says you can't guarantee accuracy as you can with a CAD viewer's measure function.

[IanR]

PDFs printed from CAD by a competent Architect or Technician will be scalable to an accuracy of less than a millimeter. 

It's pretty basic stuff, if they're not capable of achieving a to-scale PDF I wouldn't trust them with much. 

 

PDFs created from scans are of course a completely different matter, just as photo copies of a drawing would be. 

[Ferdinand]

26 minutes ago, IanR said:

PDFs printed from CAD by a competent Architect or Technician will be scalable to an accuracy of less than a millimeter. 

It's pretty basic stuff, if they're not capable of achieving a to-scale PDF I wouldn't trust them with much. 

 

PDFs created from scans are of course a completely different matter, just as photo copies of a drawing would be. 

 

Haven't we discussed this before?

 

The paper itself can move significantly (by at least 1%? - my guestimate) which I am sure Ian is familiar with though perhaps it bears repeating for newbies who land on this thread and sometimes more. So it needs to have a scale on the paper then be checked against the written numbers on site. I guess that it will move more between office and site than office and office.

 

It is a good job concrete beams are quite dimensionally stable  . "It doesn't reach the wall any more, Guv'nor".

 

My somewhat posh secondhand colour laser printer (OKI C9655 for the avoidance of doubt) has a stage in its printing process where it displays "adjusting temperature", which will standardise at least one variable.

 

Ferdinand

 

Edited October 23, 2016 by Ferdinand

[IanR]

27 minutes ago, Sensus said:

 

although as previously discussed, an accuracy of 'less than a millimetre' becomes an accuracy of 'less than half a metre' at 1:500 scale 

 

 

That's not what I'm saying 

 

Say a Ground Floor Plan at 50:1, correctly printed to PDF,  will be able to be measured, within Acrobat Reader, to within 1mm of its Full Scale dimension. 

[IanR]

1 minute ago, Sensus said:

 

And as I said, it depends on the software used to generate the PDF whether it preserves the native CAD accuracy. Some does, some doesn't. 

Are you suggesting that there is CAD software that is not able to print to scale?

 

While errors can occur,  as Ferdinand points out,  with physically printing on to paper, not such errors occur when the file is electronically printed to PDF,  as long as the Architect knows the basics. 

[IanR]

13 minutes ago, Sensus said:

 

I'm suggesting that there is PDF creator software that doesn't. See TerryE's comments, above.

 

Many CAD programs 'print' to CAD creator software (eg. CutePDF writer) as though they are sending the data to a printer or plotter. It's the creator software that then generates the actual PDF file, and no, no all of them create files that preserve the dimensions to the level of decimal-point accuracy that you gent in the native CAD format. Some don't even preserve vector dimensions at all.

 

Surprisingly, it's a fairly recent addition to AutoCAD that it can print directly to PDF with a native 'driver'/PDF creator. There are some CAD packages that still don't, some people still running old enough versions of AutoCAD that they don't have the built-in functionality, and some who just prefer using PDF creators like CutePDF writer, out of habit.

 

There are also cases where someone has manipulated or recreated a PDF file outside of CAD (for example, by editing in Photoshop or other graphics software - commonly used to add colour to AutoCAD generated drawings for presentational purposes as AutoCAD's colouring capabilities are limited).

 

 

 

Well, I can vouch for CutePDF, although I generally use the Acrobat drivers.

 

It's probably worth you getting familiar with the print options, you may be more successful with your printing.

[TerryE]

Here is clip of a sections PDF from my frame supplier.  It's zoomed to 300% and already looking chunky.  The PDF is a rasterised version.  No sudh problems wth Draftsight or VariCAD viewing of the DRW file.

 

[PeterW]

1 hour ago, IanR said:

That's not what I'm saying 

 

Say a Ground Floor Plan at 50:1, correctly printed to PDF,  will be able to be measured, within Acrobat Reader, to within 1mm of its Full Scale dimension. 

 

But at 1:50 a 1mm line will be 50mm on site or half a brick width.  

 

This is why Land Registry plans are notorious for being inaccurate as the lines are up to 3-400mm at best if they are done in a red pen...

 

CAD scaling is best done at source - put the dimensions on the plan when you do it and then there is no ambiguity. House building is not - and cannot - be millimetre perfect if you are using traditional trades as it's just not practical. If you want that then you have to go to CAM and direct export your design to be machined  and constructed in factory controlled conditions. 

 

PDF is for documents, for information and for reference. If you're using it to scale for building then you need to seriously consider your accuracy ..! 

[ProDave]

This "scaling off drawings" issue.  How much of it is not being given the correct information?

 

There was one point in our build where the builders were making the frame in their workshop and the called me for help as they were having "trouble with dimensions" So I went to have a look and they were trying to scale measurements from an elevation drawing.  I looked through all the drawings they had and none showed enough information to be precise. But somewhere in the back of my mind I was sure I had seen the information they needed.  A quick check of the full set of detailed drawings (which I had as a PDF set) showed all the information they needed, but showed the designers, when printing a set for the builders, had missed one vital drawing.  A quick phone call and I had them print out a full size copy of that drawing for me to give to the builders and all was well.

 

I wonder how many times that missing drawing was just "solved" by scaling from the wrong drawing?

 

[IanR]

3 hours ago, Sensus said:

I am successful with my printing, thanks very much.

 

That's not evidenced by your opinion on the capabilities of printing to PDF.

 

@TerryE with all due respect, that's a poorly "printed", PDF and if it were part of the delivery for a paid-for Service I would have refused it. It looks like the result of a "PrtScn".

 

@PeterW The quote of mine you have used is attempting to say that the accuracy of "within 1mm" that I'm suggesting is of the true 1:1 length.

 

Here's one I did not do earlier. This is the corner of the GA drawing for my frame. It's received directly from the Frame designers and I've just opened it up, selected measure and set the 1:40 drawing scale:

 

 

The opening I've measured using the free Acrobat Reader application is 5000mm wide, as shown by the CAD dimensions, the dimension that the measure tool puts on the drawing is the one that reads 4999.87mm

 

So, accurate to 0.13mm in 5000mm on an A1 formatted drawing that is drawn at a 1:40 scale.

 

I'm zoomed in to 200% to take the measurement. Any fuzziness of the image is due to JPeg compression. There is nothing special about the PDF, it's printed in colour at the correct A1 Size and is 121Kb filesize.

 

I could have picked any of the drawings I have received from the frame designers, or the original Architect that helped with the Design & Appearance Condition, or the Architect I used for some "Passive House" detailing work or the drainage guy that specified the land drains, or even any of my own.

 

CAD Authoring, digital collaboration and digital archiving got its act together years ago to ensure that when the paper-less society does eventually arrive, original drawings archived in digital format can be relied upon to not require legacy CAD systems to remain functioning in order to interpret a drawing. Adobe are at the fore-front of this for 2D data and are pushing hard to do the same for 3D. 

Edited October 23, 2016 by IanR

[PeterW]

@IanR I get what you are saying but you miss the point - I can use ANY CAD package to do what you show (which is a dimensioned plan so is a moot point in this discussion) but I defy you to get that level of accuracy on a building site when your average brickie does not use a laptop and PDF package to see how big an opening is, but uses a printed set of plans and a Stanley tape measure ..! 

 

It would be interesting to compare that dimension on your plan with what has actually been built and I'd expect it's +/- 10mm.  

 

 

 

[IanR]

OK, back to the OP: 

 

Quote

Is there any easy to use software that will allow me to get accurate dimensions off plans from either PDF or CAD files

 

Answer: Yes there is, the free acrobat reader application that's installed on the majority of PCs and laptops.

 

All discussion beyond this regarding level of accuracy is due to an incorrect assertion that PDFs cannot be relied upon, I'm not suggesting that the level of accuracy achievable is required by the builder on site.

 

9 minutes ago, PeterW said:

It would be interesting to compare that dimension on your plan with what has actually been built and I'd expect it's +/- 10mm.  

 

That dimension measures 5003mm on the built frame, all openings are within a few mm of their design size . Touchwood have a pretty good process for hitting the opening sizes "spot on".  But I understand your point if it were a masonry build.

[Declan52]

Doesn't matter as much as you think on a masonry build as if it's brick then the windows or doors go where it suits the bond of the brick no matter what it says on the usually ripped, dirty and wet plan.

Same goes with block but not just as bad as you can obviously cut a block to suit whatever size you need to get to.

[TerryE]

16 hours ago, IanR said:

@TerryE with all due respect, that's a poorly "printed", PDF and if it were part of the delivery for a paid-for Service I would have refused it. It looks like the result of a "PrtScn".

 

@IanR It is a print screen of a 400% zoom of the PDF.  However, I disagree with your point.  The supplier also provided the DRW for precision review and measurement take-off.  PDFs are Print Definition Format, that is for printing at the defined scale.  Taking measurements off them is a bonus and assumptions about the precision not always obvious.  As @Declan52 says, for very valid reasons, the as-built reality might differ from the detail of the plan anyway.

 

PS EDIT: Oops and mindfart.  PDF = Portable Document Format.  So much for that point!

[jack]

Let's face it, communicating via a forum isn't always the best way of getting one's point across.  IanR and Sensus, you both clearly know a lot about this topic.  I think what's happened is that you're talking about slightly different things, or perhaps have different focuses on what's important in this conversation.

 

Please, let's pause for a moment, take a deep breath, have a cup of something hot and/or strong (it's 5 o'clock somewhere) and

 

[Bitpipe]

22 hours ago, TerryE said:

@Vijay, I use Draftsight, but it can run like a dog if you use it on a typical laptop.  AFAIK, it really needs a PC with decent CUDA graphics card to get responsive performance.  Also try the VariCAD Viewer. This will open DRW files and you can zip around them, take measurements and print off extracts fast.

 

Be aware that it also the creating package renders the PDF file.  This might be using vector graphics but many generate diagrams at a give BPI for the target page size; so if you zoom in then drawing starts to look pixelated.  Hopefully your diagrams include a scale rule to validate scaling, but as Sensus says you can't guarantee accuracy as you can with a CAD viewer's measure function.

 

I relied hugely on DraftSight (on a Mac) during the whole planning & design process, using it to compare drawings from MBC and the basement SE, checking dims & taking measurements, prototyping ideas etc.

 

Would not have been able to build the house without it. It's a bit tricky to lean but you don't need to do much to interpret existing drawings.

 

Sadly the free licence expired after about 12 months and I could not get it to renew, needed to install on another PC.

[Vijay]

I've loaded varicad but how do you measure between 2 points?

[TerryE]

@Vijay On the ribbon at top there is a 2-D distance Icon (A double arrow with a ? over it.  Click on this and this exposes a pop-up ribon with all sorts of variants, but the simplest approach is to us the default and click and click, then the distance dialogue appears.  Note that Clt-scroll-whee does zoom and clicking down the scroll wheel allows you to pan.  There's bunch of VARIcad youtube videos.  OK, only a subset apply to the free viewer, but the viewing functions are the same in both. 

 

PS remember to use the @TerryE if you want to attract my attention to a post

[Vijay]

@TerryE  Cheers Terry. Do I have to enter a scale anywhere as the result it's giving isn't right at all?

[TerryE]

I never had a problem with the plans provided by the TA, MBC and my staircase company all came out in the right metric units.  So I don't know what the issue is. Sorry.  When I have this problem I just set up a simple 2 column scaling spreadsheet to enter the data values and get the conversion automatically.