Fabrication Duct in Revit attached vs non-attached Taps

[Anonymous]

My current problem is that using Fabrication Ductwork in Revit, the rectangular taps DO connect to the rectangular duct, but the round taps DO NOT connect for some reason. Even though they look correct and convert fine when using "Design to Fabrication", only the square duct taps stay attached to the duct mains; the round taps just kind of float in space. Tab select picks up the rect-rect connections but not the rect-round connections.

Another clue is that when I go to put a cap on the end of the rectangular duct, the square taps show no available connectors for a cap, but each round HETO shows an available connector.

I am using Revit 2018 Fabrication parts. We have purchased a database for ductwork, and for the most part things are working great. We have a seat of Autodesk-fabrication-cadmep to edit .itm files if we can figure out what needs to be fixed.

Is this a REVIT issue, or an ITM issue? I checked and both types of tap have the same connector. Thanks for looking.

I recorded a screencast:

https://www.screencast.com/t/DtUH9zw2i

[Lance.Coffey]

To clarify if this is an issue with the ITM parts vs Revit, can you find equivalent built in fabrication parts (that are not part of the purchased parts), to see if you get similar results?

Here is what I am seeing when I try this with built in Fabrication parts:

URL for video (where you can download the RVT atached): http://autode.sk/2s1Qm6x

[Anonymous]

Thanks for Responding, In the video attached to the reply, the issue I am having has not been addressed.

You have a rectangular duct, connected by a square-to-round to a round duct, then a straight round piece, then a tee. All those would connect beautifully in my model.

This is my issue:

I understand that there ARE parts that will work. What I'm trying to understand is; assuming I MUST use the specific tap that isn't staying connected, and also assuming that it's possible to fix the reason it's not staying connected, where is that setting?

I have never edited FAB parts for use in Revit, I need to either tell the gentleman managing our FABMEP content database:

"Please fix this tap or replace this broken tap with one that remains attached to my duct" or

"Round Taps can never attach to Rectangular ducts when using Fab Parts in Revit so I just have to live with it."

[Lance.Coffey]

I’m not seeing a difference in behavior, when I route a round straight duct into the side of a rectangular duct (they seem to connect just fine).

Can you confirm if you are able to reproduce the issue with the duct not connecting when using the default content?

Also, could you attach a small sample RVT showing the behavior you are encountering?

[Jacob_United]

Hi Andrew,

This is not a Revit or .itm issue.

You're problem is that the pattern (Fabrication Part CID) you are using is not made for connecting to rectangular ductwork as a tap. Every Fabrication Part is based on a particular CID, these are finite and are created by Autodesk. Think of the CID as a template. The tap you are using is probably intended to connect to round ductwork.

I would be very surprised if your database did not have a compatible tap, try using something else. Heck, even most round bends, transitions and adapters will connect to rectangular duct as a tap.

Failing that I would suggest delving into editing and making new .itm files with CADmep. I'm more familiar with CAMduct, but there is plenty of information on the net regarding this. Google is your friend; not Bing, not even close.

Look in your database for a fitting with the CID 24, this will work just fine.

Feel free to ask about anything more specific.