Locking reference plane to object midpoint

[Anonymous]

I'm building a parametric Revit family, and I need to lock a reference plane to the centerline of an extruded object. In tutorials I've watched, people use the align tool to accomplish this.  However, when I try this, I cannot get the reference plane to snap to the midpoint of my object, regardless of which view I'm in.  I've tried changing the "Prefer:" setting (changing it to "Wall centerlines" or "Center of core" from "Wall faces").  I've also checked my object snaps and they're all turned on.  I've also tried drawing the reference plane on the centerline of the object, but no lock button shows up.  What's going on?  I've attached a really simple "Midpoint example" rfa so feel free to check my settings.  Thanks!

[ToanDN]

Don't you mean the other way around? Locking the center of the object to the reference plane? That is how it commonly done.

Create reference planes on either sides of the center plane and give them an EQ EQ dim.  Then drag the end grip of the extrusion , snap to the side reference plane and lock the padlock.

[barthbradley]

Nest the extrusion then.  Or, use equality constraint.  Either way, you still need to use equality constraints to define center point.

...BTW: A Ref. Plane has no mid point. A Ref. Line does. 

[Anonymous]

Okay, thanks.  I'm still having the same problem when I nest the extrusion.  I could definitely use equality constraints, and that's how I might end up doing it.  I have an old rfa, made by a previous employee, that shows basically what I'm trying to accomplish.  She defined spacing between members with reference planes locked to the member centerlines.  I don't think she used equality constraints, and it looks like a clean way to do it.  I'd love to do it the same way, except I'm running into the problems in my original post.  If that clarifies my question, awesome, otherwise I'll just use equality constraints.  Thanks for your patience!

[ToanDN]

Looks like she use a nest component and align its center to the reference plane.

[barthbradley]

...or she created the equality constraint inside sketch mode! Betcha. 

[ToanDN]

.. If she did it in the sketch mode you wouldn't see the padlocks.

[barthbradley]

Point taken, @ToanDN.  Really looks ike a nested component that's been arrayed.

@Anonymous: Wanna post the family?  

...actually, the screenshot looks like it's in sketch mode presently. Everything is half-toned in background. Maybe Sketch Lines are set to different color?  @Anonymous: Sure like to see this family. It's very curious.  

[Anonymous]

Here you go!  I know it's an array, not sure if it's nested.

[ToanDN]

It is a nested family then arrayed.

[barthbradley]

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@Anonymous wrote:

Here you go!  I know it's an array, not sure if it's nested.

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You've got 3 nested families. Check the Project Browser. 

The family is constructed properly. What are you trying to do with it? Add a different size slat maybe? The slat already in in has dimensions that control it's height, width and depth ("Deep","Wide" and "Length" TYPE parameters).  If you change them to INSTANCE, you could set up the Host to change the slat size inside the Array.  

[Anonymous]

Okay, that's super helpful to know!  I'm building a family for a product that's slightly different from the grille (different panel size, different T-Bar pattern, male and female T-Bar ends).  I didn't use nested families (mostly because I started the project with zero knowledge about constructing Revit families).  It's gotten kind of messy, so I might try reconstructing it with nested families.

...still not sure why I can't get nested objects (or any objects) to snap so they're centered on a reference plane, though. 

[ToanDN · Accepted solution]

The nested family needed to be built so that the vertical and horizontal reference planes are the center axis of the geometry.  You can edit one of the slat in her family, open its floor plan view and you will see it is built exactly like that.  When you load the nested family in the main family, you can align and lock the center of the nested family with a reference plane of the main family.  

[barthbradley · Accepted solution]

@Anonymous: Also important to note: the Ref. Planes need to be defined some kind of Reference to be detected in another Family or in the Project. The default "Is Reference" = "Weak Reference".  "Not a Reference" is a dumb line. 

[Anonymous]

Ah!  That's the piece I was missing.  Thanks so much for all of your help, @ToanDN and @barthbradley!

[barthbradley]

@Anonymous: No prob.  You know, you can give two solution credits if you want. I think we gave you a team effort here.