Why is my reducing tee doesn't change size to match the connect pipe?

[lupacat111]

Hi Everyone,

It's me again, I'm a new in the pipe design. I'm trying to create a reducing tee in Revit, but when I insert to the projects, the tee doesn't change the size to match the connect pipe (well, the youtobe tutorial didn't tell me about this reality life ). I don't know how to fix it. Any information would be extremely helpful, thank you in advance.

 

Attachments are .rfa file and .csv file. Revit version: 2023.

Questions:

1. Below is my family types parameters, I don't have any knowleges about how to set up the formula with: if(), or cos(), sin(), cos()...., that's really complicated to me, so I only use the simply formula and lookup table to set up my parameters, and I'm not sure if it's correct.

 

2. Below is family types parameters from Revit build-in family, for the tick size, 0.4*..., how this value comes from? In my case, all the tee tick size are different depends OD and ID for each, they all difference, can not use 0.4*sth=my really tee tick size. for example: SS-10S Tee, ND 2", OD 2.375", Wall thickness is 0.109"

                                                                              SS-10S Tee, ND 3", OD 3.5",     Wall thickness is 0.120"

                                                                              SS-10S Tee, ND 4", OD 4.5",     Wall thickness is 0.120"

                                                                              SS-10S Tee, ND 5", OD 5.563", Wall thickness is 0.134"

These values are completely unrelated and cannot be obtained from another by applying any coeffcient.

And samething as FOD value "1.02", ND+10.6mm, 0.71*ND+33.2mm, etc. How these values comes from?

3. Every time my colleague places a newly created family into a real projects, different problems occur and it doesn't work properly. I'd like to know why. Because I still have many more families to build (elbows, flanges, gasket, butt weld, etc). If I don't know the correct way to create a family and how to use formula properly, it's impossible to build a truly functional family.

Thany you for everyone's help!

[iainsavage]

Firstly your tee seems to work okay for me.

In reply to your points:

1. You only need the sin, cos etc if you are using angled fittings - they are used to calculate the centre-to-end distance using simple trigonometry. You shouldn't need those for ninety degree fittings.

You also don't need the if/then/else formulas if you are using lookup tables.

2.a. Why are you referring to type parameters? You are using instance parameters driven by the lookup formulas and the values in the lookup table.

2.b. The tick size is primarily used to control the size of the single line 2D representation of the family in coarse and medium detail views and does not need to be exactly the same as the actual fitting diameters.

2.c. "These values are completely unrelated and cannot be obtained from another by applying any coeffcient." Yes, that is why you use lookup tables to define values which cannot be obtained from simple geometric formulas.

2.d. "And samething as FOD value "1.02", ND+10.6mm, 0.71*ND+33.2mm, etc. How these values comes from?" These are backstop values which are only used if the lookup table does not contain the correct lookup values. For example you have a 200x100 tee and its values are contained in your lookup table, so the values from the table will be used e.g. FOD would be 

If however you instead created a 200x102mm tee then that branch size would not be found in the lookup table so the "not found" formula would be used instead, for example (from your example) 102mm+10.6mm = 112.6mm

3. Seems like you need some proper training in family creation but as you were told before you should study how families which actually work are designed.

[iainsavage]

PS: you never closed out your other post so I'm not sure if you properly grasped the concepts discussed there regarding how lookup tables work etc.

You need to get a firm grasp on the difference between instance and type properties, lookup tables versus type catalogues and so on.

https://help.autodesk.com/view/RVT/2022/ENU/?guid=GUID-91270AEF-225A-49D7-BF84-1F44D1E3E216

Please ask for more help if you are still not understanding it.

[lupacat111]

Oh, sorry, I'm not sure how to close my first post. As for the lookup talbes, I think I know maybe 3 or 4 if the score is out of 10. (I created these .csv files, I mean). 

I completely agree with your point, but I’m not sure where to systematically learn how to create families in Revit or where to find the right resources. I’ve been trying to figure it out on my own. If you know of any good classes or resources, I would really appreciate it if you could share them with me.

[lupacat111]

Thanks again for aswering my previous question-that was really helpful.

Right now, the tee connects fine to 50mm and 100mm pipes. But when I try with larger or smaller diameters, the tee doesn't show any change in appearance. That doesn't seem normal.

In reply to your answers:

1 and 2a: The tee (I created one), all the parameters are instance, I didn't use any type parameters. So, if I using instance parameters driven by the lookup formulas and the values in the lookup table, I don't need to give any formula like: if(), or cos(), sin(), cos(), etc. right? so right now, all the parameters values in my tee are driven by lookup table, but still showing up incorrectly, that's what's really confusing me. 

 

2b: It's for the single line 2D representation of the family in coarse, can I change the value 0.4? or can I use this formula (0.4 * Fitting Outside Diameter 2) in my tee's parameter? 

2c: Understood, thank you very much for your answer-it's very clear and easy for me to understand.

2d: In the formula: 102mm+10.6mm = 112.6mm, why is it 10.6mm? Why not a different value? Is it a fixed vaule that must be used, or is it just a rule we follow?

3. I completely agree with your point, but I’m not sure where to systematically learn how to create families in Revit or where to find the right resources. I’ve been trying to figure it out on my own. If you know of any good classes or resources, I would really appreciate it if you could share them with me.

I really appreciate your help! Thank you very much!

[iainsavage]

Your CSV file looked okay.

Your problem seems to be understanding how it works in the family and that link that I gave you above should help with that.

There are other posts regarding learning resources.