Duct Tee Help

[brane1012]

Hello!

I am trying to make a duct tee family and I am having a problem and I need help...As a template I used one tee from the MEP library and I am trying to modify it (see Picture 1)...The problem is that I can't change the parameter "d" as I want to (see Picture 2). When I change the value of the parameter "d" the whole tee should change on the way that if the parameter "d" is bigger the elbow part should be smaller. And in my tee when I change the parameter "d" the elbow part remains the same (see Picture 2 for additonal explanation). I have also attached the file of revit family that I am working on...

[CoreyDaun]

Just on a glance, it looks like the bottom of the dimensional constraint for "d" is attached to the face of the square extrusion, whereas it should probably be attached to the Reference Plane in which the top of the dimensional constraint "e1" is attached. When creating such parametric families, I would strongly recommend first creating all of the Reference Planes and Constraints for the major points of the Family and then "flesh out" the Family afterwards by creating the geometric objects and constraining those to the Reference Planes.

[brane1012]

Hm, can you please explain that a little bit better...how can I constrain them for the reference plane and how should I do that on this family?! Do you maybe have some similar tutorial :S

Thanks in advance!

[CoreyDaun]

You can search these forums or YouTube in search of family creation tutorials. They should be relatively plentiful. I don't know of many specifically to suggest.

You can constrain an extrusion in a three general ways:

a) While creating the Profile, you can constrain the Sketch Lines with Dimensional Constraints or by locking the line to a Reference Plane or another line (which is done by clicking and dragging the line or using the Align command).

b) You can select the Extrusion and drag the grips onto a Reference Line or another parallel line and then constraint it.

c) In cases in which the length parameter is available under Properties, you can directly link that value to a Length Parameter Value.

You can refer to this post of mine on AUGI.com for an explanation of my typical family creation proccess:

 2013 Void Only Cutting half of an extrusion

[brane1012]

Uf, I know that I am pretty boring to you but I need just a little bit more assistance...

I get it that I need to constrain the extrusions for reference planes and to "name" them with the dimensions...

But my problem with this family is that I drew elbow 1 (marked as E1 on jpg) in one view and elbow 2 (marked as E2 on jpg) in another view (viewable only in section 1 - check the rfa family provided in original post). I need to explain to revit that I want the extrusion 2 (elbow 2) to be constrained for reference 1 (R1 on jpg) and for the part of the extrusion 1 (R2 on jpg). Mine problem is that I don't know how to explain revit to "catch" for the other extrusion :S I would really appreciate your help or advice...

[CoreyDaun]

Not at all, I'll help however I can!

Before I can figure out how to fix this, I have to understand the Family a little better. What is the function of "Versatz1", and how is it supposed to be related to "d"? Currently, when "d" is increased, it extends past the "cover" on the front.

[brane1012]

That's another problem...I am not quite sure how that works either... I am trying to make a template and basically I am using most of Families from the Revit library. This Tee is from the German Library because I thought it would be best for my case. The general idea was only to change the extrusion part of parameter "d" - in original German library that part was straight duct (look attachment). Now I tried to change that straight duct for another elbow which can go up or down and I thought that I won't touch anything except draw another extrusion (in other plane) and that it should work...But now it doesn't work and I don't know how to solve that...

I have attached Original German Duct Tee which I am trying to modify

Thanks for your help!

Best regards, Branimir Segotic

[CoreyDaun]

Sorry for the delay in response, here.

Where did this Family come from? I don't think this is a good one to work from. Is there an OOTB Family that is similar to what you need?

"OOTB" stands for "Out Of The Box", meaning something that comes default with Revit.

Also, try searching Autodesk Seek - maybe you'll find something worth-while...

[brane1012]

This family came from the Revit MEP German library...In the picture you can see the original German family and mine modification (how should it actually look like) which isn't completely working (as described in earlier posts) :)...

On autodesk seek I didn't find any 😞

[CoreyDaun · Accepted solution]

OK. This Family (the original) just appears a little strange to me. For instance, I was tracing the formulaic references and found references to the Length Parameter "m", which seems to have a fixed value of zero (as determined by a formula) and I see that "m1" is also fixed at 2000 mm, so I didn't see the point of them.

Anyway, the upper extrusion in your Family needs to be constrained differently, and re-size from the top in lieu of center. So, change the value of "d" to 300 mm, delete the "d" and the related EQ dimensions, select the extrusion, drag the upper grip to the Reference Plane (the one that is constrained by "Versatz1") and constrain it, and drag to bottom grip to the Reference Plane that is constrained by "Versatz1" on the bottom. Open the Family Types dialog and set the formula for "Versatz1" to "= d", and hit OK.

Now, select the dimension "Flansch d" and set the formula to "<None>" with the pulldown on the Options Bar. Create a new Linear Dimension, first click (what's supposed to be) the center Reference Plane for the upper extrusion, second click should be the upper Reference Plane that controls the extrusion, and third should be the Reference Plane that controls the lower portion of the Extrusion. Place it and click "EQ" - this will properly reset the flange. Now select the formula-less dimension and set the formula back to "Flansch d".

That should do it. Don't hesitate to ask if you run into any trouble.

[brane1012]

Oh my god you are genius...I don't know how to thank you enough...It's working...

But I have a few other (new) questions about creating this kind of families...so if I am not bothering you lot...

1. Should I link any of the connectors (see picture Connectors.jpg)? Linking connectors is important for calculations or?!

2. The newly created elbow (see picture Elbow.jpg) can go down (as now drawn) or it can go up...So my idea is to flip that family with flip control...But when I go in section view the flip control isn't possible. And in top view I can not (or don't know how) to put flip over reference plane (see picture Elbow.jpg)?!

3. Does revit have any base point (or origin point) for connectors that I should take care of?

Thanks one more time for everything...

[CoreyDaun]

Appreciate that - no problem.

1. Linking the connectors will allow "system type" to be transferred through the fitting, but I'm pretty sure that only matters when the Connector is set to Global. I searched because I couldn't remember for certain; below is an excerpt from the AU 2008 class document by Martin Schmid.

---

Martin Schmid wrote:

"Linked Connectors only have an effect when the System Type is set to Global, which is common
for fittings and in‐line components such as dampers, valves, and pumps. Essentially, Revit MEP
will try to discern the system type, flow direction, and flow values if the connectors are linked."

---

 2. I think that fall under the use of those rotational controls that appear in the Project environment by default, rather than actual flip controls. I tested, but for some reason, the modified Family does not like being flipped upside-down, and breaks. I don't know how to fix that.

3. That I'm not certain about. (I'm actually an electrical guy with minimal fitting experience.)

[brane1012]

3. That I'm not certain about. (I'm actually an electrical guy with minimal fitting experience.)

Intention of this question was more like general...Do the fittings, equipment and stuff like that have any base (origin) points on the connectors?! Because sometimes I have trouble drawing ducts or pipes in section views...It seems like he is starting to draw duct/pipe somewhere near the connector and not actually from the connector so I thought that he is having base point dislocated from the connector...

Thanks one more time for everything...

[CoreyDaun]

Families will have three Reference Planes (one on each axis) that is designated as "Defines Origin", which is found under the Reference Plane's Properties. The intersection of these so-designated Reference Planes defines the origin of the Family, and it is typically the "insertion point". I'm not certain to what extent this origin plays into fittings, but that may well vary depending on how that particular fitting was designed. This origin has no relation to the Connectors within the Family - Revit may relocate the Family (based on the Connector) to suit the Pipe or whatever it is being connected to.

[brane1012]

 2. I think that fall under the use of those rotational controls that appear in the Project environment by default, rather than actual flip controls. I tested, but for some reason, the modified Family does not like being flipped upside-down, and breaks. I don't know how to fix that.

It is interesting that I can normally rotate that family with the rotate function from the menu bar...But if I click rotate on tee in the Project environment (as you did) it breaks...