XREF'S 5

[bot1357]

Hi there,

I have had a work colleague come up to me and ask why I insert my border as an XREF. I fully understand how they work but as you may have gathered from my previous post I am not very good at explaining things. So I was hoping someone on here could type me out in Lehman’s terms exactly what are the benefits of using XREF’s.

Cheers
Danno

 

[jrfosterjr]

The bottom line advantage of XREF for the purpose you have described is standardization. If the titleblock changes, the next time you open any drawing that externally references this titleblock, the titleblock will appear with the latest changes.

One note about that, if you have VISRETAIN = 1 and make layer color/linetype changes to the XREF titleblock, they will not appear as they do in the original XREF.

External Reference files are definitely the way to go in my book. Our standard setup is one master file for a project that contains topo, utilities, etc and each user can reference it into their own sheets for presentation in whatever manner they wish. No need to make blocks of changes and copy them around to many other drawings to keep them all up-to-date. The advent of irregular viewports and multiple layouts really adds value with the use of external reference files.

Jeff Foster, PE
CE Group, Inc.
Apex, NC

 

[CADaver]

We avoid using titleblocks as XREF's for that very reason. When we sign a contract all parameters are locked, including the border. In the past we had a client that changed his border a couple of times a week, and we spent more time chasing the text locations than we did building the plant. Since then titleblocks are blocks with attributes.

In my industry, the primary function of XREF's, IMMHO, is shared design data. We'll do a Foundation Location Model that contains all the foundations on the job in their proper locations. That model is used as background data for underground piping, underground electrical, paving, surface drainage, Structural Steel Location, etc.. Then each of those is used as background for the Foundation Location Model.

 

[jrfosterjr]

CADaver,

Your point is definitely valid. I'm like you, I don't XREF titleblocks. If I were to do so, once the project was to be sealed for the first time, we would bind them. Even then, I wouldn't include any text in the titleblock, but rather have that set up as Attributes.

Good followup.
Jeff Foster, PE
CE Group, Inc.
Apex, NC

 

[chicopee]

If you have many drawings with xref for the titleblock,then any minor change into your titlbock will be relay to those many drawings, thereby elimenating to individually change those many drawings.

 

[CADaver]

Once a contract is signed, there shouldn't be any changes to the border. Think about this scenerio, a client changes his border from a standard lower-right titleblock to an Archictectural style running sideways up the right edge of the sheet. Now you have 400 drawings to open and relocate the titleblock inforamtion and issue as revisions, for no other reason than a client preference in styles.

Top that off with the client not willing to pay for the additional manhours his ignorant little change caused. What he got was the old title information locations on top of a new border, and we lost a client.

 

[rKeyTek]

My 2 cents or 25 cents on this issue ....
XREFing the border is a good idea.
Just insert the text to be modified as an "attributed block".

The benefits from XREFing a border is standard information which may affect everyone.

Project number
Project leads
General notes ... like "Progress Plot"

The project number or the suffix to a job may change if the project is 2 years long.
Project leads may also change.

And definitely progress plots of sets are normally done throughout a job.
So placing a "Progress Plot" stamp with a date underneath is nice to be placed once in a CAD file (the border).

There might be some more minor "stamps" that may be needed to be placed on drawings from time to time. And this may be due to ISO standards or a temporary need.

At least this is how it works over here.

hope that helps.

 

[CADaver]

The attributed block for data is a good idea as long as the border doesn't change. hmmm... wait a minute that's why it's XREF'd, 'cause it might change ...right?

In our industry, drawings are stamped and issued whent they are complete, we don't hold for the entire package to be issued at once, so each drawing gets its own stamps and dates as required.

Standard info (proj number, leads, notes, etc.) are handled in a separate attributed block, with values preset for the data that probably won't change. If a lead changes somewhere in the middle of the project, we want to know whose watch was active when a particular drawing was issued. For us, XREFing titleblocks is unproductive and can lead to increased costs.

 

[ohiocad]

We've got a setup here, that we use for most of our customers, where the border, which contains the border outline, project title, project number, customer name, etc. (all the info that stays constant between the sheets) is Xref'd into each drawing, and then an attributed block is inserted into each sheet for the sheet number info, drawing title, scale, etc.

This was done for a couple reasons. The biggest was file size. A couple of our customers have their company logo on the title sheets, but it isn't drawn economically (for lack of a better word... lots of hatch, etc.) Was easier to talk them into xref's than redrawing their logo. After all, they're paying us, they get what they want. With a set that contains 300 sheets, that little bit adds up. We email a lot of our sets, and 2 of our customers are limited to email attachments of under 2 meg. Xrefing the tblock cut dwg size way down on some.

Second, standardization. I know when you start with a master sheet, everything should be set, and that's that. But when you get new hires in, and they're trying to hurry and impress, they change things that shouldn't be changed, which doesn't get caught till checking. Then you've got 200 sheets that have the wrong job number, because it isn't xref'd, and they did saveas from one to the next.

From experience, here at least, xref's have saved more trouble than they have caused. But I have worked other places where they caused FAR MORE trouble than I could have believed, if I hadn't seen it. I guess it all boils down to, given the good and the bad, "Is it right for you?"

Last, it's just kind of a neat toy to oggle at the neighbors.

 

[hbendillo]

I certainly do not see your point CADavar. If an owner completely changes a border then it matters little whether it is an Xref or not. You are going to have changes to do on every sheet. When we start a project the border seldom changes drastically. Sometimes the title of the project changes slightly, a logo is added, a key plan is added or something like that. These kind of changes lend themselves very well to an Xref'd border. Things such as sheet No's, drawing titles, etc., should be a block with attributes inserted in the active drawing.

 

[CADaver]

The title of the project changes after you've signed a contract?? Bad practice business-wise. Once the contract is signed there should be NO changes to the border. Think about 10 yrs from now. Every now and again a little change occurs to the border. In 10 yrs the XREF'd border will bear no resemblence to the one you used on the contract.

Key plans? XREF'd? probably, part of the border? no.

If you have an attributed block for the titleblock info, what do you gain by an XREF'd title frame, other than two entities to deal with. If the placement of the attributes aren't going to change, then the frame shouldn't either. And if you do allow some minor change in the frame, that can be handled, nearly as easily, with an insert blockname=.

XREF'd titleblocks are, IMMHO, at best, a waste of the command functionality, and at worst a contractural problem waiting to happen.

 

[rKeyTek]

Dude,
How do you deal with users moving the border?

Another reason to XREF the "title frame" as you put it ...
is you can "lock" the layer the XREF was brought in on....
if you lock the layer as a block than you can't edit it ...
also accidental deletions are avoided with a "Locked XREF" ...

Every one here expressed good reasons for XREFing and the above benefits just add to that "PRO" side.

Maybe you might want to re-think that aspect of XREF.
Just a thought ...

Anyway
your other post on other threads have been much appreciated.

 

[CADaver]

The borders are in LAYOUT, there's no intelligent reason to move it. And just a very little training solves that problem.

If you need to have a block for the titleblock attributes, you've gained nothing by XREFing the titleframe, except the ability to modify the titleframe that shouldn't be modified after setting the contract. If you still have to insert the attributed block, just add the frame to that block and be done with it.

Case in point. A couple of years ago a client sent us his border and told us to use it as an XREF, he included a couple of attributed blocks with it. He used the same arguements as have been posted here for doing so, his choice, we complied. Six months after we completed the job, he calls asking if we can fix all the drawings on our end because he'd changed his frame on his end so much that the attributed blocks no longer line up. The changes were necessary due to changes in the company's unit numbering standards, but those changes blew-up every legacy drawing in his system. Bad business choice at the outset, and had he thought about it just a little it could have been solved any number of ways on either end.

It is my opinion, that any perceived benefit is not worth the increased risk. At the signing of contract, the border, along with all other drafting standards is FIXED. After that, making two elements (XREF frame and attributed block) do the job of one is less than productive.

But, hey, that's just me.

 

[hbendillo]

CADaver, you must work in a pretty rigid structure. Do you do a lot of government work? I know contracts in those are pretty rigid. In fact I used to do a lot of government and if after a contract was signed something was changed that caused extra work, we simply charged them for it. That would often stop those little things from happening in the future. It seems that although government contracts obligate you to do things a certain way, you can also argue effectively that it causes them to have to pay to make changes. Not everyone is agressive enough or reads the fine print thouroughly that spells their obligations to you to pursue those extra fees. In our world, mostly commercial design, we often tweak the border all the way up to the time it goes out for bid. The is the line of demarkation to us. However, we seldom completely change the basic structure of the border like where sheet numbers go.

 

[CADaver]

It's called "Petro-Chem in the 2000's" - "LUMP-SUM" and "SCHEDULE-DRIVEN" (bonus-for-early/penalty-for-late). ANY change after contract requires trend analysis, cost impact analysis, schedule impact analysis, and change order approval PRIOR to commencing with change. Costly endeavors, each. Knowing that up front, the client is loathe to make many changes for any but the most extreme circumstances. Our budgets and schedules have NO "fat" for diddling with borders. The days of COST-PLUS (time and material) jobs are only a distant, yet fond, memory.

BTW, if a client hasn't settled on his border by contract, we wonder about his process.

 

[rKeyTek]

CADaver,
ASIDE from the border ISSUE!!!

Your 1st post in this thread would imply you do use XREFs for other files.

I only ask since the rest of the posts here seemed to go off in a direction against XREFing in general.

I just wanted to confirm that XREFs do have their place in our normal work-flow ... YES????

(Just wanted to dwell on the 2nd part of the "Thread". ... "Are XREFs useful?&quot

 

[CADaver]

I had to go re-read the whole thread to make sure I wasn't misleading anyone. But to set the record straight:

XREF's are probobly the single most powerful tool within the CAD world, and probably the least explored/implemented. The capability to share work as background data means drawing it once for dozens of files across several disciplines.

One Foundation Location Plan provides background for Paving, Underground Pipe, Underground Electrical, and Drainage drawings. Each of which is in turn background for each other.

Or the ability to drop in the Piping model as you build the structural model around it, while the Piper is slinging pipe around your structural model.
Or dropping in the equipment models to make sure it all fits.

And as each file is modified, the modifications are reflected in your model.

Using XREF's for borders though, IMMHO, is like using "Miss Budweiser" for a trolling boat.

But hey, that's just me.

 

[TDevil]

I find that XRef's are great not only for keeping drawings up to date, but also keeping files manageable. My computer isn't the most up to date (I'm supposed to be getting a new one soon) especially with some of the larger models I work in. Some files can reach 50 mB, which may not be much on anyone else's computer, but are murder to a Pentium 2! XRef'ing a model is much smaller than copying it in, and therefore my computer doesn't crash every other command!
Just my 2 pennies.