Looking for Advice on Creating Roof Trusses

[artitech]

If I want to create a roof truss for a sloping roof and copy it at 2'-0" centres along my buildings length - should I use a "family" or an "in-place-family"?

I would want to be able to make a change to one of the trusses and have them all update for me automatically (which tells me it should probably be done as a family, not in-place).

If it is to be a "family", I have another question...
How can I create it in my project (I need to use the building section for reference to slopes, etc in order to create it) and then export or save it outside the project and into a family file?

Thanks.

Cory

[khomburg]

Do it as an in-place family, under Modeling > Create. You will have access to your roof when doing this and can copy the family to duplicate your trusses.

[artitech]

Do it as an in-place family, under Modeling > Create. You will have access to your roof when doing this and can copy the family to duplicate your trusses.

This is how I have accomplished it once in the past. I don't believe this will permit me to change one instance of the in-place-family and have it update all other instances automatically though, will it?

[kpaxton]

It will if you group it first, then array the truss. When you edit your initial truss, the others will update. This will have to be done separately for each different type of truss.

Along the Family route - If you create one this manner, Generic is probably best at this point (You didn't specify wood trusses or steel joists, but should work for both):

Utilize your reference planes properly.

one for each point of bearing,
one for the center,
one for the bottom of the truss.
Any others as needed to assist in the layout of the truss.

Create 2 reference lines, sloping from each bearing point. These can control the pitch of the roof. (this is optional as you can have a separate truss for each roof pitch if you want).
Add an angular dimension to the reference lines, then make a family parameter for this (Roof Pitch).
Add a horizontal dimension to the bearing point reference lines, then make a family parameter for this (Truss Width). Keep in mind If you have varying width's you'll need to create a new 'family type' to account for this.
Create your solid extrusion for your truss profile - Lock to the appropriate Reference Lines & Planes. Add appropriate dimensions to constrain the thickness of the truss chords (2x6's, 2x4's etc).
Set the thickness of the truss and add a dimension for this, then make a family parameter for this (Truss thicknes).
Once complete, create new Family parameters and flex these to make sure lines don't collapse on one another. The critical area will be at the bearing point, where some lines might get too short and fail the family.
-Kyle

[BillyGrey]

Kyle,

You are an asset to this community.

Thanks,

Bill

[GuyR]

Families are your friend, reference lines are your best friend:-) Before reference lines these sorts of families were difficult. 3 minutes of modelling and a few minutes testing and here is the basis of how you do it. Granted it needs some work but families aren't hard they just need the right culture in the office and practice.

Avoid in place families if you can. You could also make this angle driven rather than height quite simply.

HTH,

Guy

[Adam Mac]

Create 2 reference lines, sloping from each bearing point. These can control the pitch of the roof.

Hi Kyle - can i ask why you stressed reference lines in the above statement - as opposed to ref. planes? (i'm guessing)

Adam

[knurrebusk]

I´m not a drafter, but the roof fascia tool is my friend.
It is the roof profile outside the main framework, use linework-tool alot to clean up.

Nice thing is that change the profile, and the rest will follow.
Even if you have 30 roof/ridge at different heights

[mbalsom]

Try these truss families. Pitch, overhang,span adjustable also web profiles can be changed. Truncated truss"station" can be changed to determine horizontal top chord height. Place as structural beam on ceiling plane then array.

[kpaxton]

Hi Kyle - can i ask why you stressed reference lines in the above statement - as opposed to ref. planes? (i'm guessing) Adam
Adam,

There is a slight difference in how the Lines work versus how the Planes work. I will leave it to the following excerpt from the HELP file.

"You can use reference lines to create a parametric family skeleton that elements of the family can attach to. For example, you would use reference lines to parametrically maintain the angular relationships within a web truss, or use it to precisely control the angle of a door swing. Angular parameters applied to a reference line also control the elements attached to its face.

In both look and behavior, reference lines are very similar to model lines. However, there are significant differences between model lines and reference lines, such as: Reference lines are annotation objects with their own category, when selected, they display dual faces, when printing, their visibility is affected by the "hide ref/work planes" checkbox".

I hope this helps!;)

-Kyle

[artitech]

Kyle (and all who have responded and supplied some terrific truss samples),

Thanks for all the help with this.

Regards,

Cory Stechyshyn