Parametric column chamfer

[DKIVIG]

Hi,

I am attempting to create a column family with side edge chamfers. I NEED the chamfer to be able to be set to 0. Normally this will not allow an extrusion to exist (giving the error of a line being too short - both with extrusion profile and voids), which is expected.

Revit has a default rectangular column family (I am attaching a copy of it) with chamfers that CAN be set to 0 without complaining. I have been using this family as a starting point, but cannot modify its extrusion profile reliably. The chamfer sketch lines seem to be somehow special - cannot be deleted or copied.

Does anyone know how these sketch lines are made? I am trying to achieve something like this (while being able to set the chamfer to 0:

Even if it is impossible, I would appreciate some explanation over those magical sketch lines that can be 0. I can't wrap my head around those.

[barthbradley]

Edit Extrusion and Align and Lock the TIPS of the angled line to both an x and y Ref. Plane.  

[barthbradley]

see attached

[DKIVIG]

Struggling a bit to make it work with the alignment. It keeps complaining when changing the value to 0. Any chance you can provide the modified family in Revit 2023 instead of 24? Thanks.

[syman2000]

Use Void instead of sketch to get your chamfer to set as 0. See attached family for example.

[DKIVIG]

There is something I didn't quite understand in this setup. Setting Chamfer to 0 puts a 10 mm chamfer on the geometry and if I put any other value in Chamfer, it offsets the void, removing the chamfer.

But I think I understand what you are trying to do. We've tried this before, but as far as I recall, there were some complications with voids. What I don't like about offsetting them out when the chamfer has to be 0 is that it creates a larger bounding box for the geometry which might not be ideal in certain situations.

I am also very curious if I can make it work with those "special" <Sketch> Lines, that can go down to 0.

[barthbradley]

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@DKIVIG wrote:

Struggling a bit to make it work with the alignment. It keeps complaining when changing the value to 0. Any chance you can provide the modified family in Revit 2023 instead of 24? Thanks.

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[DKIVIG]

The family works the same as the original. It still uses the "unique" angled sketch lines, but it does not allow me to create new ones (or copy the old ones), so I can have more chamfered edges. I have tried aligning and locking the new ones too.

 

[syman2000]

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Revit does weird things if you set the value to 0. You can add angle to those chamfer. Even that will bring it's own complexity. Make sure you lock one of the angle line to the reference plane. That's why I give you the void example, or create separate family that doesn't have chamfer.

[DKIVIG]

How is the original family with chamfers working? It is not using angles and it allows 0.

[syman2000]

It is because the original family cannot delete the object even if you set it to 0. Press delete button will not remove the dimension, reference plane or the object. So I have to force it to delete the object itself to get it work. However if you really want the family to work in sketch mode even if the chamfer value is set to 0, then you need to add a parameter and reference plane. If the chamfer is set to 0, the X will give it breathing room to flex. See attached.

[barthbradley]

You can easily build a parametric column family with that shape from a Column RFT. Are you wondering how to do this, or are you more interested in figuring out how those angled lines are hard-wired?  

[ToanDN]

Use a void at each corner and an instance parameter to move it in and out
to create different chamfer size or no chamfer at all.

[DKIVIG]

Both to an extent. I can definitely create the family from scratch with a few parameters to get the shape and chamfer on, and just live with the fact that the chamfer cannot be 0, or the standard solution of adding voids that can be moved in and out by an offset parameter, and live with the fact that the bounding box of the component is changing.

But mostly, I'd like to know how and why the original family is working and if it is possible to replicate this behaviour and how.

The geometry is simple and doable, but can I do it without workarounds?

[Mike.FORM · Accepted solution]

Here is the family fixed that keeps the void in the same spot and just uncuts geometry when you specify a chamfer < 1.

[DKIVIG]

This is getting closer to a workaround solution that might work. I am only getting an error when setting the Chamfer parameter to 0, though, and cannot find which constraint is causing it. nvm, it was an arbitrary linear dimension that I deleted. Haven't gotten any issues by doing so yet.

Any idea?

Also, do you know if the outcome as achievable with the hard-coded sketch lines from the original family instead of voids?

[syman2000]

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If you load in the OOTB chamfer column and set it to 0, it will work.

This is how they set up

[barthbradley]

a formula will keep it from breaking at zero.

[DKIVIG]

This is exactly the family I am using as a base line. But I cannot replicate the behaviour of these sketch lines if I try to create more corners or make a column from scratch. They seem to be, as suggested earlier, hard-wired, and I wonder how and why.

[syman2000]

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@DKIVIG wrote:

This is exactly the family I am using as a base line. But I cannot replicate the behaviour of these sketch lines if I try to create more corners or make a column from scratch. They seem to be, as suggested earlier, hard-wired, and I wonder how and why.

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I am as stump as you. It seems Autodesk love to keep these secret from us and make us get frustrated with the workaround. That is merry christmas from Autodesk..lol.