Equations and Assemblies. Hierarchy design

[GisMo]

In creating an assembly, or parts that are meant to fit together, I would like to know If I can create equations in an assembly. For example, I make a box that has a top with it(two seperate parts). The box being the parent part, Can I create links or equations such that If I change the bolt holes in the box, the holes in the top will automatically be adjusted or If I change the box shape, the top will regenerate and fit the box. I would obviously like to do slightly more complicated things with this. I really like using equations when creating parts. I also have two books that don't say much about it, other than design tables and SW has a built in tutorial for that. I also like creating parts in assemblies based off of parent parts but if I ever move the part, it get warning about losing the relations. Any options that I can adjust in the settings? Thanks

[interflexo]

Of course you can.

On the parent part file define an equation where you define a variable:

Example: "Rod_Diam"= 20

On the child part file define an equation where you define a variable referencing the first one.

Example: "Rod_Diam"="Rod_Diam@cylinder.Part"

cylinder.Part is the parent part file name.

Create your features as you usually do. On any dimension you create you have the option "Link Value". This option allows you to link the dimension value to a variable. "Unlink value" breaks the reference.

Whenever you change the variable value on the parent part all the dependant features are updated including the ones in child parts if open in the editor. If parent part and child part are used in an assembly you will get what you want. These variables can be used also in mating relations, component arrays, etc. It's a very powerful feature.

I hope this helps...

[JerryFlyGuy]

OR you can do whats called Top down assembly design, where the first part drives the second part. The first part [ the box] is created and then added to an assembly. Save the "assembly" [ even though its just a box at this point], then go "Insert" --> Part or Component-->New Part, and start modeling the part, you can make lines colinear and equal to existing ones [ on the existing box] you can creat equations linked to the dimensions of the first part etc.. It's what solidworks is REALLY good at.. I've got flanges and mating covers drawn that can be resized to whatever you want them to be, you can add or remove hole, change hole sizes etc.. all by modifying 1 part and the second one follows and matches the first one.. its pretty slick.. You can get much more comlicated than just a couple parts, I've got several design's where there are upwards of 1000parts all linked and driven via some base dimensions and base level parts.. VERY VERY handy...

Jerry

[GisMo]

interflexo and Jerry,

Your tips have clarified my issues. Thank you very much! I appreciate it. I have been creating Top Down assemblies, but I guess I had the wrong terminology.

Still some issues, I have created a part using a design table and now the part is in assembly. for some reason when i adjust the part from the table, it will not update in the assembly, just in its own window. All of the parts referencing the dimension from the design table part are updated in the assembly and of course, the assembly is odd. When I switch between the model and the asm it even says updating components, which is expected. Thanks

Chad


UPDATE: I figured it out. In the assembly: Right click on the part with the design table->Component Properties->In the Referenced Configuration box select: "Use component "in-use" or last saved configuration"

[JerryFlyGuy]

GisMo, that will work but I suspect that what is really happening is your changing a configuration which isn't the same as the part in the assembly.

Ie: Say you changed the parts "config#2" and then you go to the assembly which is using the same part but it's linked to "Config#1", nothing changes on the assembly because of the config it uses. So, when you changed the setting to use the last used config, it automatically changes the part config for you [over to config #2] this is all fine and dandy, until you go back to config #1 in the part model [for whatever reason]. Then every assembly that uses this part will change back to config#1 also.. usually this isn't caught until the deadline is 2hr's old.. and your trying, for the life of you, to figure out why the parts don't fit.. [PLEASE.. don't ask me how I know this! ]

Jerry [experiance is w/out a doubt, the best teacher.. ]