Family Type Parameter Breaks Constraints - Help Needed

I am creating a family for a mobile shelf assembly. While an obvious way to create it would be to use an array, because the client needs to be able to tag each shelf unit separately, that can't be done. The client does, however, have a limit of 10 banks maximum, so I've created ten banks in hte family that are controlled by visibility parameters.

Each of the banks can be a different type of shelf (the shelf units are nested families) but they are always of the same overall length and width in any one run.

Here's my problem, Everything flexes correctly as long as the depth of the units stays the same as they were when the family type parameters were assigned to the shelf families as labels. When you try to create a new Type using a wider shelf unit, you get errors.

Without the Family Type parameters assigned as labels, all of the reference planes meant to drive the location of the shelves flex correctly.

Can what I'm trying to do even be done?

I'm using Revit 2013.

I've been trying to attach the family but the system keeps producing errors so here's a link to it: https://www.dropbox.com/s/dtfz1qv0ve...ystem-Test.zip

The family has the shelves off to the side of the rails at this time. I guess that's in keeping wih this project being "off the rails".

I was able to alter the constraints to prevent the errors when changing the Family Type parameter. Instead of constraining the bottom edge of the shelves to the Reference Plane, I constrained the bottom left corner point. First, unconstrain each instance of the shelving unit family. Then, invoke the Align command, hover the cursor over the bottom left corner of the instance, and press Tab until a larger dot appears over the corner. Click to select that point, select the Reference Plan to align, and then lock the constraints.

Let me know if this does or doesn't work for you! This behavior has something to do with that bottom edge, but I haven't investigated the exact cause...

Thanks for the tip. I'll try it out later today and let you know what happens.

Well, it's getting much, much better but something is still not right. I can get the fixed end unit to change to any size but the first and second arrays work sporadically. Sometimes I can get them to chnge to a differenct unit and then it breaks trying to put them back to the size they were before. Other times, they won't change at all without errors requiring deletion of dimensions. Even if I elect to delete dimensions, I don't actually see anything dissappear.

In the attached family I've tried to do what you wrote but don't know if I did it correctly. I locked the beginning item of each array to the array start plane using the point methid rather than the edge. When that worked but sporadically, I tried locking to the Left vertical plane, too.

In the attached family, if you have time:

Try flexing the fixed unit in any of the three types - it works fine.

In Type 2 and Type 3, try changing sizes in the first a second arrays, changing each to a different width and depth unit and then back again.

I've actually seen some shelf unit families work where other or not accepted. This makes me wonder if there's something wrong - or at least inconsistent - about the nested shelf family itself.

Edit: Just discovered something: It looks like all of the 4-Tier units are accepted but the 3 and 5-Tier units are rejected.

We're THAT close!

I took a quick look into your Family and I see what you mean. I don't have the time to dig into the specifics at the moment, but, commonly when I have to embed an Arrayed Family, I will create a specific Family for the array, load the Family into that, and create parameters and constraints to define the array and its variables. Then, I load the 'Array' Family into the host and link those controlling Parameters to the Parameter values in the host Family. I can't say for sure, but I think you can still Tag the original Family as long as it is Shared and that the 'Array' Family is not.

Thanks again for taking the time to help. If I get the time, I'll try your idea as it could simplify the rather complex non-array version I'm now using. I did try reconstruction all fo the various parts to have them centered on the XY axes (they weren't as originally drawn) just to see if that made a difference and it didn't.

I discovered today that even my non-array version acts up when changing family types. Frustrating as heck.

I may - may - have it fixed. In the non-array version, where I discovered the same problem, I noticed that the places that defind the origin were not in sync with those of the nested shelf unit family. I fixed that and then, as you had suggested, locked the lower left point - not the face-controlling reference - of each nested family to both the vertical and horizontal planes controlling its position. I'll keep testing it and also try it on the array version also. If it looks like it's working, I'll post it here.

I had the non-array family fixed and now think I have the array version set. It's much less complicated as far as parameters go.