Truss family

[ck.107547]

OK, hopefully this is an easy question. I am making a truss family where the only parameter is its depth. I have reference planes drawn for the chords and verticals, and reference lines for the diagonals. They're all locked down and it flexes fine. The chord & vertical wide flange components move fine once they're locked to the reference planes, but the diagonals won't lock to the reference lines. They always stay put whenever I flex. What am I doing wrong?

Thanks,

CK

[erikbjur]

If I read you correctly, you have to attach the end of the line to the reference plane.
Select the Align command.
Select the reference plane you wish to attach the reference line to.
Zoom in to the intersection and tab through the lines until you get the end node of the reference line. You should see a highlighted box on the end of the reference line.
Click it, and lock it to the plane.

That's what I do, and it seams to work.

[ck.107547]

Actually the problem is not connecting the reference lines--they connect and flex fine. It's when I try to connect the steel brace components. They don't lock in...

[Paul Andersen]

How are you creating your members for the truss (nested beam/framing family, solid extrusion, solid sweep with steel shape profile, etc.)?

[ck.107547]

I just click on component, select the member I want to use, and then draw it point to point. I'm guessing this is not the right way to do it. If a sweep is necessary then it will be quite time consuming to change member sizes

[Paul Andersen]

If you use the steel shape profiles for your sweep they are quite easy to change out. I did quickly try your component approach and like you I was unable to constrain the diagonal members properly. I will try to have another look once I free up a bit. Posting your family and/or a quick sketch of what you're after might help.

[Steve Mintz]

I too have tried to use components in this manner and was simply told by our reseller that this modeling strategy will not work.

I've resorted to using Solid Sweeps & Extrusions using profile families. Using this method, you can also make the actual profile (i.e. L3x3x1/2) a family parameter.

Do a search in the forums for profile families. Others nicely taken the time to "extract" the profiles from the standard structural families and save them for the rest of us to use.

I may attempt to use components in families again, but my gut feeling is that it still won't work.

[ck.107547]

Using components in this way just seems so logical. Anyone out there have any idea why this should *not* be the preferred method?

[Steve Mintz]

If you use the steel shape profiles for your sweep they are quite easy to change out. I did quickly try your component approach and like you I was unable to constrain the diagonal members properly. I will try to have another look once I free up a bit. Posting your family and/or a quick sketch of what you're after might help.
Paul, let me know if you come up with anything. I too have been unable to constrain components and have them flex properly. Right now its a big issue as I'm trying to make a BRBF family which would allow gusset plates to be selected as family parameters.

So far I have tried (in so far as components)
- Align - Lock both ends with a reference plane to a point (length refuses to change; over constrained)
- Align - Lock one end, and link the length as a nested parameter (no dice)
- Dimensioning the length

It seems very buggy to me that the length of components would not be able to flex in this manner, as they clearly can in a model.

Very frustrating... :veryevil:

[ylee_one-14]

Steve have you tried changing the strengths of your reference planes?

[Steve Mintz]

Wow, this is from a while ago (and 2 employers back, if you count myself :)).

I never tried changing the strengths of my reference planes... Have you found that helpful? To be fair, I haven't worked on on that family since the original post.