Wednesday, April 17, 2013

Vertical takeoff from a sloped pipe


Ran into a problem today with a fitting from a piping manufacturer.

We needed to run a vertical takeoff (vent) from a wye fitting on a sloped pipe. I had addressed this a long time ago, but because I never wrote it down, I forgot exactly what I did to make it work when I got the new content.

The image below shows my desired result:



Part one: You're project has to be setup to use pipe deflection, by specifying a pipe connector tolerance in the MEP settings dialog. (manage -> mep settings -> mechanical settings).



Part two: your fitting's connectors have to be "told" they can use this variable. To do this, you must open the fitting family.

Select each connector (or only the ones you want to use the "wiggle room" tolerance you just specified...)

... now here is the trick - if the connector system classification is set to "fitting" you can't do anything. (see image)... what you have to do, is click that "fitting" combo-box, and change the classification type to "global"

*Poof* a whole list of different properties populate the palette. (I'm glad I typed that, and didn't have to say it three times fast). Check the newly appeared "Allow Slope Adjustments" checkbox.

Change system classification back to "fitting", save, and load back to project. The fitting will now respond to the pipe connector tolerance.








Wednesday, June 6, 2012

Revit Revision Bubble Not Appearing?

This is so simple, I debated not posting about it. But because this is the second time this same thing got me, if for no other reason it will serve as a note to myself.

A new user came to me, and could not get the revision clouds to appear. As usual, I went through the "how revisions work" speech, and corrected the revision schedule, which was in fact incorrect.

After feeling pretty good about the quick fix, I went to place her bubble, only to get this error:

"None of the created elements are visible in Floor Plan: XX view. You may want to check the active view, its parameters, and visibility settings, as well as any Plan Regions and their settings."


Ok - another simple fix...  obviously my revision clouds are unchecked in the annotation categories tab, of my Visibility Graphics Dialog. (VG -> Annotation Categories -> Revision Clouds).... But, its checked?!


After turning on all the model categories, it worked. Then a minute or two of scratching my head.. I knew it wasn't a workset issue, or a view range issue... I remembered this got me before... The model category "Lines" was unchecked for that view. Click that back on, and everything comes in 





Tuesday, February 21, 2012

Cannot Draw Revit Pipe Elbows when upgrading to RMEP 2012?

This was too obscure to not share:

A friend of mine had been working in Revit 2011 on a project. A few weeks ago he was asked to upgrade the project to the 2012 platform. After opening the file in 2012, the only elbows that Revit would draw were 90 degree elbows. Any angle in between greeted us with a big fat “do not enter” symbol.



At first, I thought somehow the lookup tables were not being seen? Nope.

Was the working plane slightly skewed from being parallel to the Z axis? Nope.

Pipe routing dropped the elbow family altogether? Nope.

As it turns out, Revit has a sense of humor. For whatever reason during the upgrade, Revit re-set one of its default settings: Pipe Connector Tolerance.

By definition that setting is 5 Degrees.

Pipe Connector Tolerance: specifies the number of degrees by which pipe connectors may deviate from their specified mating angle. The default setting is five degrees.

However here’s what the 2012 version looked like:





This convenient little guy allowed the pipes to be routed only at angles 75 degrees or greater.

Not sure how it gets reset, but setting this value back to 5 degrees will get you back on track with routing your piping.


Friday, September 2, 2011

Create a Hatched Clearance for Revit Families


Have you ever wanted to add a hatched clearance to Revit family, could change visibility in different views, and use for interference detection? (see image). I had that question posed to me by a friend of mine, and here’s what we came up with... (pdf link here)

Thursday, March 31, 2011

Revit Families, Types and Instances

Grasping the building blocks of Revit for AutoCAD Converts

When I first was learning Revit, one of the items that my AutoCAD trained mind had a difficult time accepting was how to properly use/create Revit Families.

In AutoCAD, you have Blocks defined in a drawing (this definition you don’t see … its internal), then references to that block placed numerously throughout your drawing (these are the “blocks” end users see – technically the proper name for these are Block References, but most people refer to them as blocks). You can also maintain blocks as an external file, and bring them in when you need it, to many different drawings/projects.

So families are the Revit equivalent of AutoCAD blocks, right?  If it was that easy, I wouldn’t be writing this post! It’s close, just similar enough to lull you into thinking you have the concept grasped. But there are some things you should know, and it starts with Revit vocabulary.
First understand there are three types of Families in Revit: system families, loadable families, and in-place families. 99% of the time you hear someone talking about families, they are referring to the loadable family type. That is the focus in this article. For your reference, here are the definitions from the Revit MEP 2011 User Guide:

System Families
Loadable Families
In-Place Families
System families create basic elements such as ducts, pipes, and other elements that you would assemble on site. System settings, which affect the project environment and include types for levels, grids, drawing sheets, and viewports, are also system families.
System families are predefined in Revit MEP. You do not load them into your projects from external files, nor do you save them in locations external to the project.

Loadable families are families used to create both system components and some annotation elements. Loadable families create the components that would usually be purchased, delivered, and installed in and around a building, such as boilers, water heaters, air handlers, and plumbing fixtures. They also include some annotation elements that are routinely customized, such as symbols and title blocks.
Because of their highly customizable nature, loadable families are the families that you most commonly create and modify in Revit MEP. Unlike system families, loadable families are created in external RFA files and imported, or loaded, in your projects. For loadable families that contain many types, you can create and use type catalogs, which allow you load only the types that you need for a project.

In-place elements are unique elements that you create when you need to create a unique component that is specific to the current project. You can create in-place geometry so that it references other project geometry; resizing or adjusting accordingly if the referenced geometry changes. When you create an in-place element, Revit MEP creates a family for the in-place element, which contains a single family type.
Creating an in-place element involves many of the same Family Editor tools as creating a loadable family. For detailed information about Revit MEP families, see The Families Guide.


Revit Families are very robust, and have a lot of tricks. But this is what you NEED to know if you are just starting out.

Loadable families can be stored externally, and have the extension .rfa.

The family itself contains at least one, and possibly more, types. When a type is placed into the model, it is referred to as an instance. 

In an effort to understand the concept, I have chosen a neutral object that many of us can relate to: The Beer Keg. I created a family that falls under the plumbing fixture category (Categories are static– everything must fall under some kind of pre-defined-by-Revit category).  

The Name of my family is Keg.rfa.

Inside my keg family, I have 4 types:

  • 1/2 Barrel
  • 1/4 Slim
  • 1/6 Slim
  • Pony


Each of these types can be placed in your model, over and over again. Those resulting objects are called instances. In the sample above, I have placed three instances of the ½ barrel keg type.  (There are also 3 instances of the ¼ slim keg type.)

The relationship of types to instance is important, as it’s important to parameters, or the data, stored inside the families.

Take for example, the ½ barrel keg properties.

*Note - This is the properties palette of the family from inside the family editor – not the properties window(s) in the Revit project itself.

Let’s say the designer needs to show four ½ barrel kegs. Each of those kegs are manufactured the same.  They all have 15.5 Gallons capacity. They all have the same dimensions, etc.  Those are all properties of the type of keg (or, Type parameters). They are uniform.

Looking at the “contents” parameter above, you notice there is a (default) next to the parameter name. This indicates that every instance placed in a model, can have a different property assigned to it. This is referred to as an instance parameter. By default this parameter is filled out as “BEER”. However in an actual project, you could specify the type of beer in each keg.  For example: Sam Adams, Stella, Guinness, and Old Style are all instances inside of the ½ Barrel keg type.

I know this was a tricky concept for me the first week or so I picked up Revit, after 10+ years of AutoCAD.  Hopefully, this helps some other Revit newcomers along.

If you would like the keg.rfa  family I used for this tutorial, you may download it free here.