Family Type

[Anonymous]

Hi,

I have a Table which cannot seem to resize. I am stuck on programming the element which does not want to increase or decrease its dimensions when inserting values in the family type dialog box.

I believe that its because the reference planes are not locked onto some of the extrusions for example, the edge of the glass top for its overall width: 

As well as some equations are not entered correctly.

I know it might be a complex shape, but please if you could give me a hand to make this table work, as I roughly know where I am making the mistakes but cannot find a solution.

Thanks,

Ivan

[ToanDN]

Share your family file.

[barthbradley]

---

@Anonymous wrote:

I believe that its because the reference planes are not locked onto some of the extrusions

---

I believe you are right -- but the other way around. That is: the extrusions are not aligned and locked to reference planes. The Ref. Planes are what flex (e.g. your labeled dimension are pulled from them). 

Post the family if you'd like us to inspect. 

[Anonymous]

I have attached the file, thanks.

[barthbradley]

"I see!" said the blind man, as he dropped his hammer and saw. 

First of all, in order for the shelf to maintain a 45 degree edge angle, you need a parameter to control the offset distance (in sketch view), of the Sweep Blend's Base from its Top. If you want a 45 degree edge, then that offset distance is easy to calculate: it exactly the same as the shelf thickness. A 1:1 relationship. 

But, before you go there, you need to constrain your Sweep Blend's Top and Base sketch line work somehow. No easy task considering their oval shapes. This is absolutely necessary because the Top and Base shapes need to flex (and maintain their shape and a relationship to one another) based on the shelf thickness.  

My suggestion: build the shelf in a different family and nest it into the "main body shaft" family, and then associate parameters controlling sizing and thickness. This way, you can build just one shelf. 

TIP: the oval shapes need to be done with TWO sketch lines -- not one continuous sketch line -- with their END POINTS aligned and locked to parameterized Ref. Planes. 

[ToanDN]

How did you draw and constrain the parabolas in the first place?

In your model, you have 2 solid blends, so you need to constrain 4 parabolas.  I would simplify it by:

- create a single thick solid blend, with the bottom @ the bottom of the lower shelf, top @ the top of the upper shelf

- constrain the bottom parabola how you did it

- add a formula to constrain the dimension of the top parabola (based on the distance from the bottom and the 45 degree angle)

- add a void in the middle to make the thick solid blend become 2 thin shelves

[Alfredo_Medina · Accepted solution]

I havent' opened your family file, but, based on the image you posted, I'd like to make a comment:

A diagonal reference plane is not useful for constraining geometry. Use a reference line, instead. Reference lines can be locked at their start point to the intersection of two reference planes, and their angle of inclination can be controlled by a parameter. 

[barthbradley · Accepted solution]

Here's what I mean. The 45 degree Ref Plane in the "Front View" is just placed to show you that the sweep maintain a 45 degree edge as it flexes. Again, that angle is controlled by parameter "RB". That 45 degree Ref. Plane does nothing in the model. All the sketch line work is based on Model Lines that are constrained to Ref. Planes in the Plan View. No Ref . Lines used, except that one  you see in 3D. You really don't need that either. @Alfredo_Medina is probably pointing out a better overall construction method, but I just put this exhibit together real quick. If you can break it, then that's the real test. I didn't really try though. Have at it.