Equations and distance mates in an assembly

[charliedurrant]

Hi,

I have a situation that is easily described. Consider a flat bar that is centered in the middle of another flat bar along the long dimension. I have various configurations varying the length of the longer bar.

I want the position of the smaller bar to always be in the center of the longer one. All very simple but I can not see how to get distance mates to use eqautions eg.

LongBAR_length (LB_l)
ShortBAR_length (SB+l)
D1 (distance mate) = distance of end of SB from end LB
Eqation -> Dimension1 = (LB+l - SB_l) / 2
D1 = Dimension1

This must be possible but I have no idea how to do it...

Charlie

 

[CorBlimeyLimey]

If the bars are created using the Mid Plane option, you could use the standard reference planes for mating. This would automatically keep the bars centred on each other.


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[brengine]

If the bars were not created using the Mid Plane option, then create an additional plane in each part at the middle. This plane can be defined parametrically (preferred) or hard dimensioned (different value per configuration). Now in the assembly, mate these planes together to automatically keep the bars centered on each other.

Ken

 

[charliedurrant]

Agreed, however they aren't but they can be.... Can equations not be used in distance mates?

 

[handleman]

Sure they can. Here's the equation I used to do what you want:

"D1@Distance1" = ("D1@Sketch1@Part2.Part"-"D1@Sketch1@Part1.Part")/2

"D1@Distance1" is the distance mate dimension
"D1@Sketch1@Part2.Part" is the length dimension of the long bar
"D1@Sketch1@Part1.Part" is the length dimension of the short bar.

 

[CorBlimeyLimey]

Distance CAN be used in Equations.

When creating the Equation, simply clicking on the dimensions in the graphics area will insert them into the Equations input area. To get the distance mate dimension to show in the graphics area, double-click the mate.


Helpful SW websites FAQ559-520
How to get answers to your SW questions FAQ559-1091

 

[CorBlimeyLimey]

Mating planes or using a DT is often the easier/better/safer method than Equations.


Helpful SW websites FAQ559-520
How to get answers to your SW questions FAQ559-1091

 

[TJMcD]

You might consider using a width mate (SW2006 or later) instead of a distance mate. This does all the calculations transparently to you; you only have to select four faces (two on each of your bars), and it rides through configuration changes nicely.

 

[charliedurrant]

Hi All,

Sorry for not coming back on this thread and thanks for all the comments (I've been away). I still can't get a distance mate to use equations. If I try an equation name in the distance value box solid works says 'no'. Is there a specific method. I can use equations in a part but not in mates in assemblies....

I'll look into width mates........

Charles

 

[handleman]

Sounds like you're used to doing equations in some other program (ProE?). In SW you create all the dimensions you want to use for the equation. Then you add an equation and double-click on the dimensions to add them to the equation. Your finished, single equation will look almost exactly like the equation posted previously.

 

[CorBlimeyLimey]

Check the Help file for equations, scroll to bottom of page, Related topic > Entering Equations


Helpful SW websites FAQ559-520
How to get answers to your SW questions FAQ559-1091