assembling a bolt&nut pre-assembled assembly

[BJP]

Hi there,

Just wondering, I have an assembly with a sensor and two nuts attached and I would like to place this sensor assembly onto a number of brackets with different wall-thicknesses (meaning the position of the nuts will be different for each wall thickness). What is the most efficient solution here? Create a new sub-assembly of the sensor-and-nuts for each bracket or is there a smarter solution, eg. something with flexible parts (Im using Creo 3 with AFX)? How could I do that?

[SamuelBrantner]

Hi @BJP,

in Creo 4.0 with AFX 4.0 we made it possible to assemble connector / equipment elements with flexibility.

I could forge an example if you can update.

Greetings Sam

[BJP]

that would be AWESOME!

[kdirth]

I would suggest using predefined flexibility.  Assemble sensor with first nut relative to end and the second relative to the first.  Then follow the following:

• To predefine flexibility in a component or assembly go to File / Prepare / Model Properties. Select “change” for Flexible under Tools section.
  • When part or assembly is assembled into an assembly you will be prompted to use predefined flexibility.
  • Select a feature or part to flex, select dimension to vary, and select OK.
  • Repeat for additional feature or part flexibilities.
  • Select OK.
• To add flexibility when adding part with predefined flexibility.
  • Select Yes to prompt “Would you like ot use it for flexible component definition?”
  • Add new value for flexibility dimensions as needed and select OK.

[BJP]

I've tried this and it should work but.. for some reason I cant select dimensions in my model although the nuts are assembled with an offset. Does this sound familiar?

Actually I would like to assemble the sensor with two options: 

1. fill in a distance of the front nut with respect to the front of the sensor and mate the sensor on a bracket

2. mate the front face of the rear nut on a bracket in the main assembly. (perhaps with mechanism constraint?)

See attached image. Should this be possible at all?

[kdirth]

Be sure you are applying flexibility to the sensor assembly in your assembly and be sure to select the nut not a feature of the nut.

I have not been able to get the additional mate for the second nut to work.  I thought that leaving that constraint off the assembly or assembling it with mechanism would allow it to be constrained in the final assembly similar to how I have assembled moving cylinders.

[BJP]

Finally got to see dimensions by selecting the parts in the modeltree. Now it works like a charm!

[kdirth]

Because of how the Creo selection filter works, you need to select a part in an assembly from the tree, change the selection filter to "part", query select (right click till the part is selected), or use the "Select from Parents" button in the pop-up menu. 

[StephenW · Accepted solution]

I set up a stud-nut assy with these 2 dimensions pre-defined with flexibility.

Then when I assembled, I used the pre-defined flexibility to enter the values of the offset of the first nut from the end of the stud and the offset of the second nut from the first nut. (thickness of the mounting panel)

You can also use the tools in the flexibility dialog box to determine the panel dimension if you don't know it.

[kdirth]

I like that last part.  When using a measurement the value even updates when the thickness is changed.

[DaveMartin]

I'm wondering, do you actually want this to be a subassembly? It seems to me like you get an unnecessary level in your Bill of Materials. I think an Assembly User Defined Feature (UDF) might be more appropriate in some situations.

Assembly UDFs are at the 2:34 mark of this video:

https://www.youtube.com/watch?v=Zb5ey4OthW0&t=