Restricting pipe fitting to 45 and 90 degrees

[chas_esau]

I'm having an issue restricting this pipe fitting to 45° and 90°. It will still come in at 22.5° if I draw a pipe between 1° to 33°. I'd like it to either error out or automatically place a 45° elbow.

I'm also having an issue with it pulling data from a lookup table for the 45° elbow. I get inconsistent units when I try and have it look at the angle as a secondary lookup.

I've seen several responses from @fabiosato that has solved similar issues to this but I can't figure out what is wrong with my elbow and lookup table. 

[s.borello]

Go to pipe settings_angles and check the box to only use specific angles... add your 45 and 90 and see if it works for you.

[chas_esau]

Unfortunately I still want other pipe angles available. I just want to lock down for copper piping specifically to only include 90 and 45 angles.

[fawzimasri7137]

This is not a complete answer... just something for you to look at...

It seems that the Bend angle calculation in the file is working correctly.  but it is whatever is  drawing the angle is incorrect, as it it is not using the "Bend Angle" parameter in your family.

if you look at the attached, you can see that Bend angle in the properties says 90, when i drew a 72 degrees angle.  so the if statement in your family works fine.  72 degrees should be translated to 90 degrees.... so something else is wrong.

i will have a look at it some more and see if i can find anything else with my limited knowledge of how the fitting is drawn 🙂

[fawzimasri7137]

you can lock things per pipe material... so if you do  this on copper, your cast iron should not be affected.

you can also create a separate pipe type to handle this copper type you are working with.

[chas_esau]

@fawzimasri7137 

I'm not seeing where you can lock angles for specific pipe types. It still looks like it's a global setting. I'm using Revit 2020.2.

[chas_esau]

For some reason, this elbow family is able to use Bend Angle in it's lookup table formula without getting inconsistent units.

[fawzimasri7137]

you will find it under pipeTypes edit... so select a pipe that your fitting will be used in, and then click edit type in the propsety panel... then see attached.(note in my attached, i used Cast iron No-hub pipe type since that 's what was availble for me then.  so make sure you select you material type, the copper one.)

it is here where you can also define a new copper material that behaves differently than other copper material.

but really from my brief look at this, i am thinking the error lies somehwhere else in the family and not in the angle specification.

[chas_esau]

As far as I can tell this is still a global change and can't be applied to specific pipe types. 

[fawzimasri7137]

Have you tried it and it did not work for you?... what was the issue, since that is how i am constricting the angles per material /pipe type.

[iainsavage]

It has nothing whatsoever to do with pipe material.

It is the bend family which needs to be restricted to 45 and 90 degree options by using angle parameters and an if/then formula to force it to only allow two angle options.

[fawzimasri7137]

@iainsavage  yes you are correct in what you are showing here, and i have tested that in his file and that if statement in the family works as expected.  see my previous response.

what you commented on, i think, was my response to his message 3, where he wanted to lock angles per different PipeTypes  and i suggested creating different material types where he can choose what angles are allowed.... so i may have misunderstood him.... if i did apologies.... was just trying to help...  but if i misunderstood the usage of the Angles in the material under pipeTypes, then, please don't leave me in the dark...

[fawzimasri7137]

@chas_esau 

i opened the family and tried different values for the Angle to see how it affects the sweep.

I tried 72 and it drew a 72 degree fitting... not what you want, but it did that.

So then i tried other angle values and all produced an error that i had to cancel out of.  so by fluke i hit on angle that works.... there are probably others, but maybe this is a starting point for more debug.  I don't think you should have any errors, and frankly i don't know what Revit does in this case... uses default values, or what.

please see attached.

[iainsavage]

@fawzimasri7137 , firstly I understand that you are only trying to help. We all are, that’s why we post on the forums. There was no intention to insult or upset you in my post.

Your focus on pipe materials and locking angles in the segments dialogue is however incorrect and is not, in this instance, helping to solve the issue.

The angles setting which you highlight is the same angles setting found under mechanical settings (MS) and restricts, for all pipes, the allowable angles between pipes. It is a global setting and not specific to any material or pipe type.

It also does not determine which part of the lookup table to use in order to build the geometry of the fitting and it does not prevent the fitting being made to any other angles.

If the geometric shape of the fitting is different for 45 and 90 versions then there needs to be a formula in the fitting family which extracts the correct data from the lookup table but that does not in itself prevent the fitting from being created at other angles. To make the fitting conform to only certain angles there needs to also be a formula which says “if the initial angle  is less than “x” value, make the final angle 45, otherwise make it 90”. The second angle parameter is the one then used to create the fitting geometry. The fitting should then only ever be either 45 or 90.

In my opinion, but please don’t hesitate to contradict me if I am wrong and please keep posting on the forum.

[chas_esau]

@iainsavage You are correct in what I'm looking for. I'm trying to use that Bend Angle parameter to pull 45* data from the lookup table. Whenever I try and use it I get inconsistent units though. That's one issue I'm running into. The other is trying to lock this down so it only allows 45/90 degree's. 

@fawzimasri7137 iainsavage is actually on the right path. I don't think I was clear enough with what I was wanting but thank you for your suggestions.

[fawzimasri7137]

@chas_esau, @iainsavage 

thanks for clarifying.

but i was curious if these errors that i showed you in the fitting family had any impact ... Should we even see any errors if i change the "Angle" from within the family?

Whatever  "Angle" value i tried, i could not get the family to show me that its "IF" statement for the "Bend Angle" had any impact on the length of the arc of the fitting.  Sure it calculated the correct value for the "Bend Angle" ( 90 or 45), but at the end of the day it either drew the "Angle" as i specified even if it is not 90 or 45, or it error'd out.

[iainsavage]

I tested this last night and now I think the solution is a combination of my suggestion and setting only certain angles in the mechanical settings>pipes>angles as suggested by @fawzimasri7137 . My method only allows the fitting to adopt certain angles as you requested but if you try to draw any other angles you get routing errors so you also need to set the 45 and 90 snap angles to match the allowable angles in the family.

[fawzimasri7137]

hi @iainsavage  i did not know that you can lock what angles to accept by listing them in the Angle parameter... cool.

but i am still wondering why the "Bend Angle" is not sufficient to lock out other angles.  unless Revit is drawing the Elbow using the values from "Angle" and not "Bend Angle"

[iainsavage]

I think that's the issue. There seems to be a circular relationship in that you can use a formula and second angle parameter to only allow the fitting to adopt certain angles but it seems that Revit still wants to use the actual Angle parameter taken from the pipes, so if that Angle doesn't equal one of the allowable bend angles then the "constraints not satisfied" error appears in the family and the bend isn't created.

So for example the formula might say if Angle <45 then bend angle should be 45  and that will work but only if Angle is 45 in the first place!

So re the original post by setting this restriction in the family and only drawing pipes at the 45 and 90 angles then the correct geometry should always appear and at any other angle an error should occur. Which is (I think) what was requested.

[chas_esau]

@fawzimasri7137 @iainsavage 

I still don't think there's a way to lock specific type pipes. When I do that, it just loops me back to the global settings. You can restrict specific Segments and Sizes per pipe type. But once I click on the Angles tab, it's global.

I don't think the errors in the family matter that much when changing to certain angles. The Bend Angle parameter is just taking a value from the Angle parameter which is then supposed to retrieve the correct values from the look up table. Problem is I get inconsistent units whenever I try to use the Bend Angle in the Lookup formula.

I don't know how I can lock the Angle parameter to 45/90 without referencing another parameter. The Angle parameter is what Revit is feeding into the elbow whenever you are drawing bends and what not.