Friday, 24 April 2015

Weird Revit Railing Stuff - part 5 - Extensions / Terminations


In my previous post I described how top rail / handrail terminations in Revit are not visible in plan, thus rendering them useless for 2d documentation.  They have another 'feature' that makes them unreliable for use in any model:

Unreliable Rail Extension Length

When you first define a new railing type, with a top rail that has a termination and extensions, the termination goes outside the length of the extensions:
If you then change the railing for some other railing type, and then change it back to the original type (with extension + termination), the termination is now within the extension length - meaning that the whole railing length gets shorter.

Of course you can't see the extensions (unless you select the railings) - but the rail just looks shorter.

This has been acknowledged by Autodesk as a bug, so no doubt it will be fixed in due course.  Let us hope that they also fix the visibility issue, which is not yet acknowledged as a bug - last I heard it was "As Designed".

Possible Workaround

If you really want to use terminations, and don't mind about the plan visibility issue, there is a workaround to the extension length issue:
  • Go to a section view and select the top rail
 
  • Make sure you get the top rail by Tab-Select, otherwise you'll get the whole railing
 
  • Click on Edit Rail in the ribbon
  • The extension line will show blue, but note that the termnation has already moved
 
  • Edit Path (note the Edit Rail Path is different from normal Edit Path)
  • The extension sketch lines are now editable - drag the extension sketch line to exactly where you want it

  • When you finish editing, the termination will be where you want it to be, and will not move without your permission
The main problem with this workaround is that you have to edit every single instance of the extension/termination.  The other option might be to just make the extension longer than required (by the termination length), and live with the fact that Revit will shorten it - of course you need to swap the type to make it do so.

Organic Railings

  • While you are editing the extension path, you could have a bit of fun, and curve the extension line.  Antonio Gaudi would be proud of you

  • Or you could go really crazy

  • But even Gaudi wouldn't like this result as his designs were always very considered even when looking arbitrary


Railing designed by Antonio Gaudi, Barcelona



Dimensioning Terminations

Another issue:
You cannot dimension terminations in section (or plan, obviously), which is a limitation for serious documentation.
Perhaps you could create a detail view and place a separate termination component that is invisible in all other views?   Another nasty workaround - but what else can we do?


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