Issue with Fastener Assembly

[ALautenschlager]

Hi All,

I seem to be having an issue when it comes to inserting fastener assemblies. I've included a picture to try and help explain things.
I effectively have a cylinder (dia 3000 mm), to which a drive sprocket is bolted. The problem I come across is that NX recognises three coaxial holes (two in the cylinder and one in the sprocket) resulting in the bolt being inserted in the sprocket (correct) and the bottom stack to sit on the opposite side of the cylinder (wrong). I've tried unselecting the third hole, but this results in no change to the fastener assembly. I can't seem to select an end face (I'm assuming this is because the end face would be cylindrical).

If I uncheck the "Find coaxial hole" feature I am unable to select the holes indivdually as it selects the array of holes in the cylinder.

Cheers,

Alex
NX7.5

 

[JohnRBaker]

I suspect the software is doing exactly what it's supposed to do, it found a series of coaxial holes which it took as being the design. Since there was no provision to make an explicit selection for the 'ending' face, the system did what it thought was correct in this albeit pathological situation. That being said, this might be a useful Enhancement Request to be be made. If you agree, please feel free to contact GTAC and make this request.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.

 

[ALautenschlager]

Thanks John,

I tried running the same scenario using square faces and I don't run into problems - I'll submit an ER.

Are the fastener lengths meant to update when the thickness of the stack changes? At the moment I am finding that the fasteners stay the same lengh regardless of how I change the stack.

Alex

 

[JohnRBaker]

No, there is no attempt to link the length of the fastener to the 'stack' thickness. The size however is linked to the diameter of the hole as well as it's location, but that's about it.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.

 

[ALautenschlager]

John,

I am finding that the fastener size does not seem to update with the hole size, however the fastener is still associated with the hole position. "Delay after Edit" is turned off and I've tried to edit the fastener stack using the "Edit Reusable Component" option. The model is as simple as it gets, a single rectangular extrude with one hole. The thing is, I was trying out different fastener combinations yesterday and did not have any problems with fastener sizes updating, then I included the Siemens Machinery library and things seem to have gone awry. I have switched back to the standard reuse library in case this would make a difference, it hasn't.

Alex

 

[JohnRBaker]

Actually I misstated that. The Fastener Assemblies are not 'associated' for size but when you select the hole(s) when placing the fastners, the system will automatically select the correct size fastener (diameter and length) based on the standard hole clearance and depth/thickness of the assembly at the time that you place the Fastener Assembly. Once it's been placed the only thing still 'associative' is the location of the holes.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.

 

[ALautenschlager]

Thanks again for your help!

 

[Arkance/PhoeNX]

The location is only associative if you create assembly constraints when you create the fastener assembly.

Anthony Galante
Technical Resource Coordinator

NX4.0.4MP10, NX5.0.6, NX6.0.5, NX7.0.1, NX7.5.0-> NX7.5.5 & NX8.0.0 -> NX8.0.2, NX8.5p15

 

[JohnRBaker]

Perhaps, but it is just a simple 'toggle' option in the Settings section of the dialog.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.