Tuesday, August 28, 2012

A few shameless plugs...for AU 2012!

I gotta love our marketing people...they've really been grabbing on to social media and getting ourselves known for being thought leaders in the BIM arena.

So they put together a little highlight reel for the classes I'm teaching at AU this year, showing a few of the projects we've worked on in Revit, along with a few pics from previous classes...check it out!

Here's the list of classes I'm doing this year - in case you missed it:
Class ID: MP1414
Class Title: Revit MEP 2013 - On Steroids!
Wednesday - 10:00am

Class ID: MP1461
Class Title: You did WHAT? Revit MEP and AutoCAD P&ID? Amazing!
Thursday 1:00pm

PS - for the class above, I'm really excited about this one - we're doing stuff that everybody says we shouldn't be doing - but it's not just about the programming. It's about how we went through the decision and planning process, to come up with a solution that was cost effective for the company while giving us a competitive advantage in our market.
Class ID: MP1465-L
Class Title: Fast Content for AutoCAD MEP 2013
Tuesday - 5:30pm

Class ID: MP1470
Class Title: Supercharge your AutoCAD MEP 2013!
Thursday - 10:00am

Class ID: MP1477-L
Class Title: FASTER Families for Revit MEP!
Thursday - 5:00pm

Class ID: MP1478-L
Class Title: Perfecting the System for the Revit MEP Project
Wednesday - 8:00am

And you thought I was a geek...see you in Vegas!

later - David B.

Wednesday, August 22, 2012

Fixing Acute Angle Pipe Deflection and other Piping Errors in Revit MEP

This tip comes straight from the top, from my buddy Dave Pothier...even though he's management now, he's still a geek at heart - gotta love it...

We had a recurring couple of problems with fittings we had defined for Ductile Iron pipe. When Autodesk brought their new versions out a short while ago for the AWWA standards, we were still having some issues, so we had a chat with Dave about it.

Problem 1 - some fittings at angles like 45 degrees could not be created, and we kept getting a "line too short" error - even though you could set the angle in the family, and it would work fine. As it turns out, my techs were modeling an existing plant on a project. To keep from getting crazy plant dimensions, they did what any good CAD tech would do - they set the units to 1/2" and 1".

Then we sailed in trying to place fittings that were accurate down to 1/16" - so when these fittings would try to fit under the higher scale, they couldn't be placed. We changed the project units down to 1/32" and everything works again. Go figure...

Problem 2 - this one was a doozy, and we had a lot of back and forth about it. When we finally did a web session with Autodesk, we were explaining how mechanical joint pipe connections have to be able to flex up to 5 degrees (2.5 each way) around a fitting, since all of this work is buried underground (and gasp, dirt does move). We also had ongoing problems where we could get pipe to deflect at angles great than 90 degrees (since the fitting angles were all between 0-90) but not at acute angles (when the deflection needed to occur, since these fittings don't exist as standard). Their fittings weren't doing deflecting, but then Dave noticed how we had the pipe connector set on the fitting. Here's part of his response:

"...Select the (pipe) connectors and temporarily change the system classification from “Fitting” to “Global”

Once you do that, you can turn On the Allow Slope Adjustments check box. After turning it on, set the System Classification back to Fitting. Do that for both connectors.

Now the fitting should allow the pipe to deflect without the fitting’s angle adjusting. I’m not sure how great of an angle you can have but it should work for what you are doing. Let me know if this works for you."

Now we when make the connection, we get piping deflecting the right way:

Sometimes it's just the simplest things - but thanks again to Autodesk for helping us out, and really get the most from this great package! I'll make sure we get this into the Revit MEP lab I'm teaching at AU, so you can see how do fix this first hand.

Have a great evening! David B.

AutoCAD P&ID - A couple of quick tips...

We're going whole-hog (for those folks not from the South, this means that we are ardently pursuing a course of action - it just takes a lot less typing to say it) into AutoCAD P&ID, and really gaining the benefits over the old-school lisp and vanilla AutoCAD methods we used before.

But like any other Autodesk application, you've got to follow some rules. Here's a couple of tips that will help with some of the errors.

Off-page connectors - Autodesk released a fix for these not too long ago, but there's a better way to screw this up. If your pipe line segments between the connected drawings are not the same type - for example, you used the Primary Line Segment in one drawing, and then used Secondary Line Segment in the other drawing, where you wanted to make a connection - you won't get the tag properly labeled. We did this with several lines, just not paying attention. Off page connectors require the same line segment type to properly connect, so check this in both drawings before you implode.

The other good one relates to Validation. We've been using the Validate tools on P&ID objects, but we also place all of our geometry in paper space - since we're not working at scale. If you configure the Validate tools to check for Base AutoCAD objects, you might not get anything to show up as an error - even if you've added all kinds of cheatin' shortcuts.

The Base AutoCAD Objects check only looks at model space - so if you are importing old P&ID's to convert to intelligent objects, do your work in Model space, and then check. You'll find all of your random linework and be able to edit them right out of your shiny new diagram.

I've got more, but fixing all this has made me tired...time for a nap...

Later - David B.

Thursday, August 2, 2012

Drawing Yard Piping in Revit MEP

In some projects, you might want to add the piping that connects between buildings and structures as Revit pipe instead of Civil 3D. I do this when I'm trying to maintain a connected system that doesn't go out beyond a campus, or scope of a project.

It can get a little tricky, so here's a few tips. First, make sure you have your site file linked in to your view. You need that as a point of reference. In our case, we have a project that is based on shared coordinates (site is linked center to center, then we acquired the coordinates from the site file to line our project up to those coordinates).

Next, get your levels added. You can either work from an overall relative level elevation of 0, which we do include on some of our projects. When you have this level in your project, you can use the actual invert elevations from the existing or proposed pipe.

If not, you need to do a little math - for example, you have a level defined at 303'. The pipe invert is 322.43'. You need to do the math, subtracting the level from the true invert, so our pipe is at 19.43'. You don't need to do any conversion if your project is in feet and inches instead of decimal feet - typing this value in will do the conversion for you.

You also need to know if the invert elevation is to the top, middle or bottom of pipe. That will come in handy as you start to draw the pipe.

Next up - calculating slope. This is why I decided to add this post - for the life of me, I couldn't do the basic math to convert slope to inches, so being the geek I am, I did a Google search and found a great table from a book called Basic Engineering for Builders, written by Max Schwartz. Here's the conversion table:

Before you add the pipe make sure you have the right fittings, such as the ductile iron mechanical joint library. We use a modified version of an old CADWorks library based on Clow for ours, but make sure your outside diameters are correct.

Now you're ready to add the pipe. From the home tab, select the Pipe command. Set the size and invert elevation for the offset, after doing the math. Next, select Justification to bottom, middle or top based on what you have as you invert elevation.

If the pipe is sloped, make sure you turn slope on. The direction you're drawing determines whether you use slope up or slope down. If you're starting from the highpoint, select slope down. Set the slope to the right value - if the values you were given were based on percentage, use the table to find the inch to 12 inch value (re: .5% = 1/16"/12" slope).

After you review this, pick your second point. And this is where the fun begins. Sometimes, Revit doesn't want to add a right angle to the pipe, especially if the view is not at right angles. What you want to do, when this happens, is rotate your view based on a pipe segment. Make sure your view crop region is turned on.

Select the crop region, and then pick the Rotate tool from the Modify tab. The center of rotation will show up in the middle of the view. Move your mouse over the center, pick it and drag it to the end of your pipe. After you've moved the center, you can rotate the view around this point. You can either pick a line that is orthographic first, then the center line of the pipe. That usually works, but sometimes you have to pick the first line for the rotation as the centerline of the pipe, then pick an orthographic line relative to your view. Either way, get the pipe in view flat.

Once it's flat, the fittings should work as designed. If you want to see this solution live, then join me at Autodesk University this year in Las Vegas, for my class, Revit MEP - On Steroids. We're going to have a lot of stuff revolving around site based projects in that class. If you can't make it to AU, it will be available after the event if you're signed up as an AU member. You'll have a handout with pretty pictures, and they may even have a recording of the class.

Hope this helps - happy BIM'ing...David B.