what is best "protected" cad file to send to contractors?

[gweng]

What is the best form to convert a .dwg file to so that the contractors can snap, inquire, etc. the features of our Autocad 2009 file but cannot steal the blocks/design out of the drawing? We do Civil site plans in ACAD2009 and have to send out plans for concrete contractors, site utilities providers, etc. and they need to snap distances, see elevations, identify bearing/distances, etc. but we are concerned about the copyright of our engineered drawings of the base plan without an engineer's seal. Is DWF the best format to save this dwg to in order to give them access without them being able to alter or pilfer the design dwg?

[billy342601]

For the situation you are discussing, my office sends out DWF's unless it is in the contract for the client to get actual DWG's. It is up to our client to determine if the contractor is to get DWG's or DWF's based on their individual contracts.

That is just how my office operates, but it may differ from one location to the next. Someone else may have another idea, and this issue has been discussed in other postings here as well.

[TerribleTim]

. . .DWF's unless it is in the contract. . .
QFT! ! ! ! ! ! !

[RobertB]

I agree with the other two... DWF, with layers published.

[rkmcswain]

We do Civil site plans in ACAD2009 and have to send out plans for concrete contractors, site utilities providers, etc.Just out of curiosity, why do you have to send them a drawing?



but we are concerned about the copyright of our engineered drawings of the base plan without an engineer's seal.

Sounds like you don't trust them with your IP.

Do you not have a contract that spells out the deliverables?

[TerribleTim]

. . .Do you not have a contract that spells out the deliverables?
We don't either, even though I've been preaching about it for the last 3 years, which is why. . .

. . .Sounds like you don't trust them with your IP. . .
No, . . .I dont, . . .With anyone. . . Is that a bad thing? :grin:

[rkmcswain]

No, . . .I dont, . . .With anyone. . . Is that a bad thing?
Not at all. But in that case, it's easy, just don't send them anything -or- find new partners/clients/consultants, etc.

[Railrose]

We do tif files. It's a corporate standard, especially since we went to Documentum.

[RobertB]

We do tif files.That does not address the OP's wish for measurement and so on.

[Railrose]

Sorry, I missed that.

[gweng]

Thanks for all the discussion, it was very helpful. These contractors are probably trustworthy for what they are doing with the drawings (doing their takeoffs and coordinating other utilities with their own). We are also trying to comply with the Texas Engineering Laws that saw that when transmitting the final version of engineering work electronically, one must "employ reasonable security measures to make the documents unalterable".
Thanks for the input.

[stelthorst]

Some of the answers in this thread remind me why the nirvana vision of a true BIM world where data is shared freely from design to final building turnover may be a long time coming

I work for an electrical contractor and when I request data for a project it's because it will help make my job easier not because of an evil plot to steal design concepts from architects and engineers. That being said I don't know of a single CAD operator who won't "borrow" a block if it's better than the one they currently use. Personally, I'm flattered when someone "borrows" my block.

To answer your question, I would prefer to receive DWGs as it gives me the most flexibility to do my work but a DWF would be my second choice. Sometimes I do not need to do anything with the drawings and in that case PDF (preferred) TIF, and other similar formats aren't a problem. Since you state the contractor needs to get distances and such from the drawing and that you're leery of sending DWGs I would suggest DWF.

I hope I didn't offend anyone with this post, I was just trying to add a contractor's point of view to the discussion.

[rkmcswain]

I hope I didn't offend anyone with this post...

Not at all.

We share our civil DWG files all the time with all sorts of firms. Sometimes we know this up front and other times it's not part of a contract, but frankly we don't have anything in these drawings that is worth more than we are willing to lose.

On the other hand, I can see where the OP is coming from because I have heard of cases as drastic as someone taking someone elses drawing and putting their own title block and seal on it and stealing a job away...

[archie.manza]

As a consultant company like us, we should send our drawings as dwg format. Technically, the drawings is not protected but they cannot change or alter it unless we are informed and the one that protecting us is the laws.

[tedg]

Not at all.

We share our civil DWG files all the time with all sorts of firms. Sometimes we know this up front and other times it's not part of a contract, but frankly we don't have anything in these drawings that is worth more than we are willing to lose.

On the other hand, I can see where the OP is coming from because I have heard of cases as drastic as someone taking someone elses drawing and putting their own title block and seal on it and stealing a job away...
I guess it depends on who you are and who you need to send drawings to.
If you're a consultant being paid to produce drawings for another firm, that firm owns the cadd files when you're done.
If your a design firm and you're contracting an outside consultant, and they need your backgrounds to do their work, they're "part of your team" anyway and your contract should state that it's proprietary.
If you're a design firm and a bidding or construction contractor wants your cadd files to make their job easier (for take offs and distances), well I would have a problem giving them cadd files unless they were paying extra (allot extra) for them and/or it was part of the contract.

We send PDF's for the most part, sometimes TIFF's.
DWF's are nice, but I'm not sure you could get anymore distances off them than putting a scale on a piece of paper. (I may be wrong, I don't know allot about dwf's)

[Maverick91]

I guess it depends on who you are and who you need to send drawings to.
If you're a consultant being paid to produce drawings for another firm, that firm owns the cadd files when you're done.
If your a design firm and you're contracting an outside consultant, and they need your backgrounds to do their work, they're "part of your team" anyway and your contract should state that it's proprietary.
If you're a design firm and a bidding or construction contractor wants your cadd files to make their job easier (for take offs and distances), well I would have a problem giving them cadd files unless they were paying extra (allot extra) for them and/or it was part of the contract.

We send PDF's for the most part, sometimes TIFF's.
DWF's are nice, but I'm not sure you could get anymore distances off them than putting a scale on a piece of paper. (I may be wrong, I don't know allot about dwf's)
I like to send out .pdf files, myself. Most people have a comfort using these files. The DWF file hasn't caught on as much.

Check out Autodesk Design Review (http://usa.autodesk.com/adsk/servlet/index?siteID=123112&id=4086277).

[archie.manza]

I guess it depends on who you are and who you need to send drawings to.
If you're a consultant being paid to produce drawings for another firm, that firm owns the cadd files when you're done.
If your a design firm and you're contracting an outside consultant, and they need your backgrounds to do their work, they're "part of your team" anyway and your contract should state that it's proprietary.
If you're a design firm and a bidding or construction contractor wants your cadd files to make their job easier (for take offs and distances), well I would have a problem giving them cadd files unless they were paying extra (allot extra) for them and/or it was part of the contract.

We send PDF's for the most part, sometimes TIFF's.
DWF's are nice, but I'm not sure you could get anymore distances off them than putting a scale on a piece of paper. (I may be wrong, I don't know allot about dwf's)

I agree with Tedg, we us a consultant sometimes required to send a PDF and not only a dwg files.

[TerribleTim]

. . .when I request data for a project it's because it will help make my job easier not because of an evil plot to steal design concepts from architects and engineers. . .

While I understand what you are saying, here's my thinking. What I've learned since my introduction to this gig is that in reality, like it or not, Architecture is 75% risk management. So while I'm not worried about someone "stealing our design concepts", there is a large amount of effort put forth in this trade to avoid having that data corrupted after we've had our name/firm attached to it. When things go sideways, and often they do, the bottom line is, do you have the documentation to back your position? So while I don't mind sharing DWG files with consulting firms, the original question stated "to send to contractors". I don't want to share any IP with a contractor, period. My subs? They can have every file I draw. But the contractor? I don't trust any of them. Heck, I was one at one time! And I wouldn't have trusted me either! :grin:

[nelson]

DWF's are nice, but I'm not sure you could get anymore distances off them than putting a scale on a piece of paper. (I may be wrong, I don't know allot about dwf's)

Just to jump in on this discussion...

tedg, with the new release of Trueview 2009 (http://usa.autodesk.com/adsk/servlet/index?id=6703438%26siteID=123112) there are options to measure distances. This also is a snap feature, and the options let you determine the precision of units to measure to. I think with Autodesk opening up the DWF viewer, and giving it a major face lift, dwf's might make a comeback over pdf.

Also in Acad 2008, you now have the ability to xref in a dwf file. So a contractor can "Use" the dwf's now (in a 2d use), by rt clicking the dwf frame you can add a simple clip boundary, turn layers on/off, and option to snap to areas in the dwf. The "redlines" are stored in the dwf, and not brought into the drawing with the xref insert. But you can use the "Markup Set Manager" (ctrl-f7) to open the redlines in the dwf into your dwg file.

Hope that helps

[stelthorst]

I don't want to share any IP with a contractor, period. My subs? They can have every file I draw. But the contractor? I don't trust any of them. Heck, I was one at one time! And I wouldn't have trusted me either! :grin:

Alright, I'll show my ignorance, what's IP?

I'm not sure what trust has to do with supplying drawings. The hard copy documents issued at bid time are the determining factor of what is and isn't part of the bid. Therefore the contractor could take the drawing files and modify to their hearts content and it wouldn't change what was bid.

I guess I'm just wondering what you think the contractor is going to do with your drawings that makes you not "trust" them?

[TerribleTim]

. . .I guess I'm just wondering what you think the contractor is going to do with your drawings that makes you not "trust" them?
Who knows what they might do. But it's best if they don't have any tools that might end cause us mitigation later. Thus I lean toward not sending them DWG files.

[RobertB]

Alright, I'll show my ignorance, what's IP?Intellectual Property

[stelthorst]

Intellectual Property

Obviously of which I have none. Otherwise I would have known what it was.

Thanks,

[rkmcswain]

...with the new release of Trueview 2009 (http://usa.autodesk.com/adsk/servlet/index?id=6703438%26siteID=123112) there are options to measure distances. This also is a snap feature, and the options let you determine the precision of units to measure to.

Actually, there is NO access to the units command in TrueView, so you are stuck with the current precision settings saved in the drawing.



Also in Acad 2008, you now have the ability to xref in a dwf file. So a contractor can "Use" the dwf's now (in a 2d use), by rt clicking the dwf frame you can add a simple clip boundary, turn layers on/off, and option to snap to areas in the dwf.

You have to know what you are dealing with though. If the DWF author isn't careful or doesn't know how to adjust the plot settings, you could end up with a DWF created at a low DPI which will cause your measurements in Design Review or in AutoCAD (with the DWF underlay attached) to be off. Layers can be omitted from a DWF also.

[nelson]

My Mistake, I meant to say Autodeks Design Review 2009. This works with DWF and image files. True View only uses dxf & dwg files.
See image of units precision option.

[cjehly]

No CAD files = hostile design team, and possibly dishonest.

:arrow: note to self: MUST DOCUMENT EVERYTHING!!! (order 4 more cases of binders)

Sorry, but as a Sub, at least 70% of our job is now "risk mitigation". ;-)

[Norton_cad]

DWF or PDF.
I remember a long time ago, we had an old ink pen plotter that was taking forever to plot, and I convinced the boss to purchase a thermal plotter. Now instead of 20 mins a plot, and all the hassel of the pens, about 20 seconds a plot was the result.
However, as time progressed the thermal plot faded, and within a month were unreadable. We found this ideal, when sending drawing data to site, as the drawings had a shelf life.
I wonder whether invisible ink would have worked instead. LOL.

[jaberwok]

I guess the ultimate "safe" version is a plot on paper?
Maybe using invisible ink ^^^ . :-)

[stelthorst]

I guess I'm still confused as to what evil things we contractors (sorry I used the "C" word) are going to do with your files.

The simple fact is the "issued for construction" or "issued for bid" drawings are the official drawings for a project. A contractor (there's that "C" word again) can erase everything from the CAD drawings and it will not change what was bid or what is to be built.

We request CAD files in order to do our job quicker and more efficiently. As a detailer for a large electrical contractor it is my responsibility to look at the architectural, structural, civil, mechanical, plumbing, and fire sprinkler drawings and try to route my conduits and cable trays in a manner that is cost efficient to the company and does not conflict with the structure or any of the other trades.

Having the CAD drawings available allows me to xref all of the aforementioned drawings into my drawing and hopefully find a clear path. Not having CAD files available makes my job a lot more difficult and increases the chances of problems and conflicts during a project.

~climbs off soapbox~

[RobertB]

~climbs off soapbox~I am glad you climbed on to it! And what happens to this "protected" ideal when Revit takes over the world?
:veryevil:

[cjehly]

I am glad you climbed on to it! And what happens to this "protected" ideal when Revit takes over the world?
:veryevil:

Video killed the radio star... :mrgreen:

[Comach]

Interesting discussion!

My 2c:

A number of contributors have mentioned sending out PDF files - what was not mentioned is that PDF files can be reverse engineered back to DWG files.

As a major civil contractor it is essential that other services, whether third party or in-house are able to accurately relate their engineering design to yours - I would therefore suggest that a DWG file is the best format for distribution - it may be prudent to include a disclaimer to ensure that the end user checks that the DWG he/she has is the most up to date, that dimensional responsibility and usage is at the end users risk and that the intellectual property remains with the originator.

It is important that everyone works together in achieving an accurately engineered end product for the client - if that means having to share data I don't see any problem with doing that. I also don't see a problem with people 'pinching' details from your drawings if it saves time and improves efficiency for others.

If you are concerned about traceability/responsibility of drawing changes or corruption by third parties then this can alleviated by ensuring the client always receives a copy (PDF or DWF) of the issued drawing to third parties as a matter of record.

Finally I think there should be less paranoia and more positive thinking in this line of work - remember that a good engineered product and eventual repeat business is the end game and showing a willingness to work-share with others goes along way to achieving that goal.

[msmith.tsap]

A similar question but a different angle:

A casework manufacturer has requested cad files of the casework elevations we prepared for a school project in Revit. At a minimum we would have to export to dwg all of the specific elevations involved.

The "curmudgeon" in me thinks that this is my work, I put the time and effort into preparing the drawings and here the subcontractor wants to use our work for his own use at no expense to himself. There may even be some liability issues there for me. Not sure.

The other side of my mind really cannot see a good reason not to. Local subcontractor, good reputation, etc. Not really a trust issue.

Just the thought of "giving away" my work bothers me.

Any comments?

MarcTSAP

[stelthorst]

Any comments?

MarcTSAP

You know I have comments. :)

If you have read any of my previous posts on this subject you will know I'm a big fan of data sharing.

Is this a competitor or a subcontractor who does installation only? If it's a competitor I'd say don't share.

If it's the installation subcontractor, is there data that can be obtained from the CAD drawings that aren't on the printed drawings? (ie dimensions)

If there is information in the CAD drawings that will make the installation go easier/faster than it's to both of your advantage to share the files.

[msmith.tsap]

I love comments.. That's what keep these forums going!

I am an architect. The casework subcontractor is the one asking for the dwg files. He will use the cad files to prepare shop drawings to manufacture and install the casework. Same info on dwg file is available on printed construction documents. The dwg files are only being requested so they do not have to spend the time redrawing our elevations and save money for them.

I like the idea that either James or Aaron indicated to charge for each file.

MarcTSAP

[stelthorst]

I love comments.. That's what keep these forums going!

I am an architect. The casework subcontractor is the one asking for the dwg files. He will use the cad files to prepare shop drawings to manufacture and install the casework. Same info on dwg file is available on printed construction documents. The dwg files are only being requested so they do not have to spend the time redrawing our elevations and save money for them.

I like the idea that either James or Aaron indicated to charge for each file.

MarcTSAP

Couple more comments.

First, how does reducing your subcontractor’s profits benefit you, your company, or your client?

Second, since they are a subcontractor look at their bid and see if they specified that they would create backgrounds for their shop drawings. If the answer is yes you could ask him for a credit since he doesn't need to do this work. Even if he didn't specify anything you could still ask for a credit and see what his response is.

Lastly, construction is a funny business and work comes at you in all directions. Helping him out now may make him remember your firm the next time someone asks him if he knows a good architect.

Just my 2c.

[kimlance]

Hi:

I'm with Scott on this. If the contractor needs cad files to make the job go smoother then all the power to him and if someones takes one of my blocks that I've created to make his life easier then good for him.
Are we not all on Augi here to find and improve the way we draw/design our drawing as quick as possible. One other thing to consider is without the signed seal the drawings are considered imcomplete.
Just my 2c.

[cmason]

I almost always insist on sharing my dwg files, and this is why:
You have to remember that anything anyone sees on paper, or PDF, or DWG, or PDF, can easily be reproduced. Therefore, nothing is secure, ever. Secrecy contracts is my most powerful tool, then if I catch someone using my designs, I have legal rights. If you just don't want to save someone the time of drawing your lines, circles, and arcs, well that's just stingy. :-) If you really don't trust the company you are dealing with, there is always the "in-person" meeting, where they get to look at your drawings and ask questions...
Good Luck, CM

[dgladfelter]

Long story short - my preferred digital transmittal format is DWF. With PDF the defacto standard, this isn't always possible, but we've been convincing one client at a time. In my experience once you spend a few minutes to actually show a client what DWF can do, they begin wondering why they ever requested PDF.

The problem however seems to be with the fact few CAD users really know what's possible with DWF. I cant tell you how many users have given me a look of amazement after showing them how to compare 2 DWF's and quickly see what's changed (http://www.thecadgeek.com/blog/2007/06/07/design-review%e2%80%99s-digital-light-table/).

Heck, even I am guilty of this to some degree, as I had no clue you could embed a proper insertion point into your DWF until one of my users asked me to help him a few months ago. In essence the recipient can Xref the DWF file, and it insert at the correct coordinates in their drawing. From there they can of course snap, measure, and the like directly from AutoCAD.
http://www.thecadgeek.com/blog/2008/09/17/georeferenced-dwf-files/

Like many things, it's all about perception. If you blindly send out DWF files, than yes you'll face a barrage of complaints from clients. On the other hand if you spend some time to educate your clients, with the spin of "hey - I'm giving you more than you could ever had with PDF", you accomplish your goals, while putting your client first. A win-win for everyone.

[Comach]

The problem however seems to be with the fact few CAD users really know what's possible with DWF. I cant tell you how many users have given me a look of amazement after showing them how to compare 2 DWF's and quickly see what's changed (http://www.thecadgeek.com/blog/2007/06/07/design-review%e2%80%99s-digital-light-table/).

You can also compare PDF documents with Adobe Acrobat.

[dgladfelter]

While it may be true each DWF and PDF share many characteristics, the key advantage to DWF is that Autodesk gives the functionality away for FREE with Design Review. Adobe Acrobat 9 Standard currently retails for $299. When it comes to tools needed for design analysis I'd argue the two are just about equal. Thus why pay for something you (and your clients) could otherwise have for FREE?

[Comach]

Historically PDF has always been the preferred format for electronic document deliverables whether it is for cad drawings or other project documenting and consequently it is already well established. So companies will have Acrobat installed as standard in their business operations - cost therefore is not the issue.

I suspect that one reason why Clients are keen on PDF is to receive deliverables in one format for all project documentation including project schedules, procedures, manuals, design data, vendor data and of course drawings - it makes it much easier for them to manage the huge amounts of data generated by a project and it can be a very secure format too.

I personally prefer DWF, but it has only recently become a viable alternative to PDF for cad drawings, but I am confident in time it will achieve greater acceptance - albeit for a short time.

[rkmcswain]

Historically PDF has always been the preferred format for electronic document deliverables whether it is for cad drawings or other project documenting and consequently it is already well established. So companies will have Acrobat installed as standard in their business operations - cost therefore is not the issue.

Take a typical situation.... "Joe Cad Tech" who is dealing with "Bill Consultant" who requests a drawing (yeah, they probably want the DWG, but that is another story...) -- so anyway, your average "Joe" probably doesn't know about DWF, but let's say he does and fires one off to "Bill"... Bill's secretary (Jane) checks his email and Bill tells her to "print out that drawing that Joe sent me"... 99 times out 100, Jane can't open the DWF, period. Even if Joe sends instructions and a download link to ADR, is Jane going to install it? Does she have the necessary rights to install it? Joe starts over and sends Bill a PDF and all is fine...

The above is the main reason that PDF continues to dominate the world of digital file transfer...

If you can get two CAD managers at each company to support DWF file transfer - then more power to them. I don't think there is any argument that DWF can be the better file format...

[cadtag]

Well, DWF has the other problem in that it's only supported on a single OS platform. No Mac, no Linux, no Solaris, no SkyOS, no Plan9, no etc etc etc. Whereas a PDF can be opened and read on darn near anything, and as far as a huge percentage of people are concerned, PDF works just fine.

Do the people who need to look at lots of documents from numerous sources need such a specialized viewer that only handles DWF? For their purposes, PDF is the format of choice. It's also a far better archival format than DWF - well documented and well understood.

DWF is a wonderful tool -- for CAD nerds and design geeks. Autodesk has made substantial improvements in turning ADR into a really usable tool, and with 2009 is actually getting close to having a trackable red-yellow-green toolset that works well with DWGs (Markup Manager).

that doesn't make it a good publishing choice for the world at large.

[TerribleTim]

Take a typical situation.... Joe starts over and sends Bill a PDF and ...

...
Actually, what you meant to say was -

Joe starts over and sends Bill a PDF and the email won't go through because it's a site plan drawing and the PDF file size exceeds their email file limitations by a ton, whereas the DWF was only 1/10th the size of the PDF and sent without any issues.

:mrgreen: :mrgreen: :mrgreen: :mrgreen: :mrgreen:

[rkmcswain]

Actually, what you meant to say was -

Joe starts over and sends Bill a PDF and the email won't go through because it's a site plan drawing and the PDF file size exceeds their email file limitations by a ton, whereas the DWF was only 1/10th the size of the PDF and sent without any issues.



Possible of course, but then Bill's secretary is still going to drive her I.S. department nuts trying to figure out what to do with a DWF file... :mrgreen: :mrgreen:

[cadtag]

Actually, what you meant to say was -

Joe starts over and sends Bill a PDF and the email won't go through because it's a site plan drawing and the PDF file size exceeds their email file limitations by a ton, whereas the DWF was only 1/10th the size of the PDF and sent without any issues.

:mrgreen: :mrgreen: :mrgreen: :mrgreen: :mrgreen:

Well, that;s just as much a factor of Joe not having a clue how to create efficient PDF as it is anything else. My trick for getting the smallest PDF possible that's still quite readable? Smaller than Ades, Adobe, cutePDF, or DeskPDF?

scan a hardcopy in on my okidata..... often down 90% in size, and still looks readable on screen

[framedNlv]

I work for an electrical contractor and when I request data for a project it's because it will help make my job easier not because of an evil plot to steal design concepts from architects and engineers. That being said I don't know of a single CAD operator who won't "borrow" a block if it's better than the one they currently use. Personally, I'm flattered when someone "borrows" my block.



and then...........

Alright, I'll show my ignorance, what's IP?


WOW...


Try paying an employee to make blocks, convert blocks to the new dynamic block and/or annotative blocks just to have them borrowed.

Just because you asked for the files to do you job faster doesn't give you the right to "borrow" them for your use.

I put hundreds of hours into making schedule templates, you want them too?

Hundreds of hours into textstyles, layering............the list goes on.

If you want to use the files for the project, ok. If you want to borrow our hard work to make all of your work faster and better, NO. If I want to share our work I would post it for download.

DWF's are sounding better everyday!!!

Chris

[stelthorst]

Try paying an employee to make blocks, convert blocks to the new dynamic block and/or annotative blocks just to have them borrowed.

Just because you asked for the files to do you job faster doesn't give you the right to "borrow" them for your use.

I put hundreds of hours into making schedule templates, you want them too?

Hundreds of hours into textstyles, layering............the list goes on.

If you want to use the files for the project, ok. If you want to borrow our hard work to make all of your work faster and better, NO. If I want to share our work I would post it for download.

DWF's are sounding better everyday!!!

Chris

Hi Chris,

I'm by no means a lawyer but if I understand the meaning of intellectual property correctly I wouldn't think blocks, layers, textstyles etc would fall under this definition.

I sense that I've insulted you with my comments and if I did I apologize. My intent was to bring a different perspective to this conversation not to insult people.

[Norton_cad]

Urban myth of DWF & PDF.

Abobe scheduled a meeting with Bill Gates at Microsoft, and asked that an Abobe light version be installed in the new OS Vista. Bill asked how much will it cost, and Adobe quoted some large sum of money. Bill rang security & had Adobe booted off the premisies.

AutoDesk scheduled a meeting with Bill Gates at Microsoft, and asked that a DWF viewer be installed in the new OS Vista. Bill asked how much will it cost, and Autodesk said no charge. Vista OS opens DWF files with no software installation required.

You can do allot with DWF files (Layers/Block lists/Red pen mark-ups/Combine sheets into a book/etc), you can't do as much with PDF. DWF is free, PDF is not. PDF's may be upgraded with more tools at some point, but it will still cost you. Also PDF secure locked files, can easily be printed to a DWF file, and thus edited anyway. Secure files are total fiction. I suggest you acept the inevitable that plagerisum is here to stay, and move on...

[Hammer.John.J]

adobe reader is free, right, last i checked.

Little story....

A company I know, subbed out their irrigation work. Sub gave us cad files, we stripped down most of the cad files to show only linework shown on paper prints. our client, didn't like some of the design, changed the cadfiles, printed them on a nice 1050c and issued them to the contractor.... we never knew about until we made a field visit and got to the bottom of what happened.

long story short......... don't give out cad files and expect them to stay the same and most of us here probably have a similar story or fear it.

we lost money on the job, the extra required to make the revisions and get blamed (although inaccurately and falsely) for the end product.

anything can be converted to cad if you have a scanner and the quality gets better with construction docs because they usually at 20scale or less for civil drawings.

one last bit... send out a survey cad file to a contractor with traverse points, vertical and horizontal controls, knowing they have their own survey crew and see if you get a call back for stake-out, lol.

[jcurebanas]

The Bottom Line is this is total gross negligence on autodesk. They understand their product is being sold to competitive businesses and their product is a software designed 100% inside and out to produce INTELLECTUAL PROPERTY and they do not even offer basic solutions to protect this intellectual property. All they need to produce is a file format that DWG's can be published in which acts as a "template" so that subs can open, move things around and draw in but never be able to copy/paste out of. As designers and drafters we have to have an option to design inside a DWG, pass off the file, and be confident that that file is protected from pirates. But autodesk will probably never do so for fears of lawsuits because everyone knows there is usually a way to reverse engineer everything and they can be caught in the middle by selling a false protection. Maybe it is not gross negligence, but it still sucks

[kmwpgca]

We have had situations with certain clients who require autocad drawings as deliverables, but then turn around and pass them on to our competitors or contractors to use or modify our design. We started using CADlock (www.cadlock.com) for those clients with the understanding it was to protect us from them reverse engineering our designs.

Most of our clients prefer PDF and only one takes DWF, but only during review stage. We still deliver DWG to clients that agree to our terms in the original contract of them owning the drawings but we own the intellectual property.

[david_peterson]

From inside of acad, you can apply a digital signature. I thought that was it's purpose. To protect your drawing from being edited. Not that I've ever used it, since there's usually a way around just about anything.

[USMCBody]

I thought this was funny... Straight from the help file... This part is all nice and good. lovely lovely...

A digital signature is not the same as a digitized signature. While a digital signature helps prove your identity and a drawing's authenticity, a digitized signature is nothing more than an electronic version of your own signature. It can be forged and copied, and has no real security value.

Digital IDs use two keys—a public key, which anyone can use to validate a digital signature, and a private key, which is known only by the originator of the digital ID. The private key is used to create the digital signature. To learn more about digital IDs, digital signatures, and public and private keys, search the Internet for these terms.


and then This is the funny part.....

Note-Once you attach a digital signature to a drawing file, it will either be valid or invalid. You cannot remove the digital signature from the drawing file. If a digital signature was attached to a drawing in error, save the drawing in DXF format, open the DXF file, and then save it in DWG format.

They seem to tell you how to Hack it and remove it.... in the same sentence...

[charlie.bauer341340]

If you are worried about the seal, get an electronic signature to imbed in the file. That will retain your legal rights even if there is not title block with a seal on it.

[cadtag]

I thought this was funny... ...
Note-Once you attach a digital signature to a drawing file, it will either be valid or invalid. You cannot remove the digital signature from the drawing file. If a digital signature was attached to a drawing in error, save the drawing in DXF format, open the DXF file, and then save it in DWG format.

They seem to tell you how to Hack it and remove it.... in the same sentence...

I'm not sure I see any humor, removing a digital signature is meaningless in that having _no_ signature on a dwg would be equivalent to having an invalid signature. Either case, presuming of course that the originating party retained a read-only signed copy, such a drawing file, with a missing or invalid signature, would be compelling evidence that the file in question was modified post delivery, and the originator would be off the hook for any liability due to the modified file being used.

[cadtag]

The Bottom Line is this is total gross negligence on autodesk. They understand their product is being sold to competitive businesses and their product is a software designed 100% inside and out to produce INTELLECTUAL PROPERTY and they do not even offer basic solutions to protect this intellectual property.

It's not Autodesk's job to protect _your_ copy-righted designs. It's yours, and yours alone. For the minority of people who believe they have a need, there's Cadlock, and they can buy it as they need it, wthout expecting every other Acad user on the planet to fund its development by Autodesk

'Intellectual property' is a non-existent thing. It's a sloppy term that concatenates multiple separate legitimate legal concepts, and blends them together with the basic intent of conflating and confusing things that are distinct; e.g. trade secrets, copyrights, patents, and trademarks, and extenging that coverage to things that have no legal standing or grounds for protection. Protections and legislation that are appropriate for trade secrets are totally different from patent protection.

[USMCBody]

True haveing no signature is an invalad thing, but if there is no signature was it ever there...... As long as you have your copy with it I guess your golden... But that is no different then you always archiveing a copy when it goes out and saying if your copy doesn't match mine... But then something is better than nothing if it worries you.

Either way the one thing we all 'worry' about is someone modifying our model and creating blueprints that still have our name on it. and then not owning up to it when something goes wrong...

And I'm spent...

[david_peterson]

Who says you ever have to send your title block to the contractor? We usually strip all title block info off. We also make them sign an agreement that makes us not responsible for anything with regards to the drawings or revit model that we've sent. Not perfect, but it does help me sleep a little better at night.

[kruithofk]

You could go old school and cut the CAD files to a CD. THat becomes the record copy.
Liability is the biggest factor to NOT send CAD files. We've heard a story about a contractor changing the size of some steam piping on the job. When that line ruptured, the engineer was sued and couldn't prove he issued the drawings with the correct size.

[USMCBody]

If you ever sent PDF's to a contractor or hard copies? Then they have your title block. If you have any skills at Photoshop and AutoCAD you can remake anything. It's like your lock on your door. If someone really wanted to they would get in your house for whatever they would be looking for. But what the lock on your door does is make it just a little harder for someone to. Hopefully hard enough that it would discourage them enough from stealing from you.

I'm all about making it harder but when do you stop and say the risk isn't worth all of this just bits and pieces of the making it harder on the contractor process for us... When does it take to much time or effert or money... Either way it is something that 'management' should sit down and decide. So far I haven't done the digital signature thing in my career, but maybe it is something that my company would want... But throw into Revit and you are forced to change something's. Do you change it for Revit Projects only or company wide... It's not an easy decision to make that is for sure.

[cadtag]

CD-Rs are nice and all, and they make a good internal record, but it would take a pretty incompetent judge to accept that as a record copy in a liability suit. It's a pretty trivial matter (if one is willing to defraud) to burn a CD that contains anything I want it to, with any date or name, and there's no forensic method AFAIK to identify when it was burned.

wet-signed and sealed, preferably embossed, are the accepted method of hard copy record documents. For digital records, a digital signature is about the only thing that will cut it.

FDOT does something slightly differently in their electronic submittal process -- essentially hashing all the files in the submittal package, and including the final hash value submitted as part of the submittal. Any change to any file results in a different hash, so it's easy to know that something was changed between submittal and use. May not be easy to tell what changed, but you can know there was a change.

[wolfgrrlone]

I guess I'm still confused as to what evil things we contractors (sorry I used the "C" word) are going to do with your files.

The simple fact is the "issued for construction" or "issued for bid" drawings are the official drawings for a project. A contractor (there's that "C" word again) can erase everything from the CAD drawings and it will not change what was bid or what is to be built.

We request CAD files in order to do our job quicker and more efficiently. As a detailer for a large electrical contractor it is my responsibility to look at the architectural, structural, civil, mechanical, plumbing, and fire sprinkler drawings and try to route my conduits and cable trays in a manner that is cost efficient to the company and does not conflict with the structure or any of the other trades.

Having the CAD drawings available allows me to xref all of the aforementioned drawings into my drawing and hopefully find a clear path. Not having CAD files available makes my job a lot more difficult and increases the chances of problems and conflicts during a project.

~climbs off soapbox~

I think what the OP may be thinking of is not what's bid, but what it built. If a failure happens down the line, and a file was altered (or had the ability to be altered) that would shift blame from the true culprit to the OP. And I think this is the risk that the OP is trying to mitigate.