Trusses: What edge does the reference line refer to?

[doni49]

I'm working on the roof framing for my bldg and I'm having difficulties with the Trusses.  I'm using the OOTB Pratt 6 Panel Truss in Revit 2016.  Is there a way to control to what edge the reference lines refer?

The first image below is taken from Acad (via a different project previously done using Acad).  The solid lines are the truss members as the engineer want so see them.  The dashed lines show what the Pratt Truss family is doing with the centerlines.

The second image shows what I'm getting in Revit when I place the truss and assign types to the various members (2x8 Top Chord etc).  The green lines in the second image, show what I need the centerlines on the diagonal web members to look like.  Basicaly the centerline of the diagonal should meet the bottom or top chord where the vertical member hits said bottom or top chord.

Also is there anyway to avoid having to select each member one at a timem unpin it, extend it, cope it & pin it again?  Who in their right mind would think the would just end at right angles like that?

[Anonymous]

I have found that the truss tool is a good way to quickly get things in place but I usually break it up and use a group instead so that I can adjust things.  I believe you can click on each member and change the z reference to addjust the placement. You may have to unpin it for this adjustment as well.  An Assembly might work well too (similar to a group).

[Rafal.Gaweda]

It follows Analytical Lines.

If you are not concerned about Analytical Model you may try to do it this way (also manual) :

[doni49]

@Rafal.Gaweda,

Any ideas why the diagonal web members are NOT lining up with the web lines provided by the family?  When I select the truss, I see the blue lines (analytical lines?) and they appear to be EXACTLY where I want the center lines of the members.  But as you can see in the second image above, they're NOT.

I've attached my test project file for your review.

[Rafal.Gaweda]

Any ideas why the diagonal web members are NOT lining up with the web lines provided by the family?  When I select the truss, I see the blue lines (analytical lines?) and they appear to be EXACTLY where I want the center lines of the members. 

Truss member centerlines = analytical lines when bar is pinned

Example after unpinning and disjoining 

(Change bottom chord section onto 12x16 to see the diffeence)

[Rafal.Gaweda]

Don,

Keep in mind that Revit is not a structural detailing software so creating detailed model for almost "shop" drawings can be cumbersome and time consuming.
Maybe you can use ACAD or Advance Steel for this.

[doni49]

---

@Rafal.Gaweda wrote:

Truss member centerlines = analytical lines when bar is pinned

Example after unpinning and disjoining 

(Change bottom chord section onto 12x16 to see the diffeence)

---

But what I'm showing in the image is BEFORE unpinning the truss. 

I place the truss and look at it in elevation view before doing anything else and the centerlines of the members DO NOT LINE UP with the analytical lines -- see the same thing.

[doni49]

It gets worse.....

I went ahead and manually tweaked the truss (even though I don't see why it SHOULD be needed -- the members should be following the blue lines as is) and then once I had it the way I wanted it, I copied the truss expecting that copies would look just like the original.  I was greeted with the following message:  "Coping applied, but no cut was made. Adjust Coping Distance or Extension parameters."  The first image below shows what it looked like after making these adjustments.

Then the new truss (copy of the original) looked as shown in the second image.

[Rafal.Gaweda]

Send me Original (from screen shot above) revit file (the one adjusted but before copying)

[doni49]

After posting my last message, I continued to try troubleshooting.  On Friday, I deleted the truss and started over.  I haven't been able to reproduce that particular issue (yet).

But when trying to manually tweak the individual members (and I'd still like to know why it's necessary -- WHY doesn't the member follow the line as specified in the family?), I've noticed that grip editing the member often doesn't place it where I want.  Please see the attached video (in the zip file).

[Rafal.Gaweda · Accepted solution]

If you want to do something more precisely you have to "explode" this object (Remove Truss Family)