IFX fastener with custom geometry

[Ben8]

I am looking for a way to create a fastener with _custom_ geometry, meaning that the screw should have geometric features that don't exist at all in any of the IFX screw types.

 In particular, I am currently looking for a way to create a captive screw that would have the geometry of DIN912 but a captive thread (rod).

See attached image - the existing dimensions in SCREWTYPE01 would remain, but additionally I would need a reduced-diameter rod size DC (to make it captive) , as well as full-diameter cylindrical face height DH (it may be slightly different from just a thread height B). I marked my new features and their sizes in red.

Is this possible in IFX? I would imagine, I may use any SCREWTYPE1 part as a starting point, modify the geometry, add two extra dimensions as required, adding control of these extra dimensions in the .dat file (i'd keep the "SCREWTYPE  1" in the .dat file) and hope it would work.

However before I try that myself I'd like to know if that sounds like it should work. I am worried that even if I manage to make it work, the IFX may be running some other code on the system level that im not aware of as a user, making this custom-geometry screw unstable, thus risking making our project files unstable later.

An easy way out would be to just use the a family table for captive screws, but having an option to easily add washers or easily switch between standard DIN912 and captive DIN912 is why i'm wondering if this is possible in IFX.

I am using Creo 9 and Windchill.

 

@OliverGräbner  can you please advice? Thank you in advance!

[OliverGräbner · Accepted solution]

Hi @Ben8 

you can add your custom screw. This is no problem.

As base type you should use SCREWTYPE 01 and add a custom icon for this type which shows your captive screw.

NOTE: The preview (2D in Dialog and 3D in Creo) will only be displayed for the selected type.

All columns in the *.dat file are handeld in this priority:

1. Search for an existing dimension with column name and set given value.
2. Search for an existing parameter with column name and set given value.
3. If either a dimension nor a parameter exist IFX create a new 'STRING' parameter with the name of the column and set given value.

Hope this helps.

If you need more details, please let me know.

[Ben8]

Thank you @OliverGräbner for assurance and your explanation, this is very helpful.

I even think this section should be written up as an article in Creo manual.

I will aim to build that screw now. In the meantime, could you let me know if feature names (not dimension names) are important and can they be changed? They seem to be named intentionally so I wonder how critical is it?

This is ScrewType01 prt model tree:

 

Many thanks

[OliverGräbner]

Hi Ben8,

you can rename the features like you want.

They are not important - only the dimension and parameter names are relevant.

In addition the Placement References (SURFACE, AXIS and ORIENT) can have names or you can use the geometry item id.

[Ben8]

Thank you @OliverGräbner 

I have started building this part and I've noticed that the first revolve feature had an internal sketch in original IFX part.

I would like to avoid it - I am aiming to build this part as IFX item for now and make it a bought-in item, with a possibility to "save it as" new part if and when required in the future, and make it a machined component instead of having it bought in (e.g. if we won't be able to buy the required length). So I am aiming to make it future proof thus a desire for external sketch. Second thing was that this original IFX part had missing origin (in other words - missing a default coordinate system), and also References button greyed out for some reason and I couldn't figure a way how to add the origin and references to it:

Because of the above, I thought it will be just easier for me to start with a new part and name all dimensions / parameters as required. I did that, and IFX Instance Generator has generated instances just fine, but when i try to insert that screw through IFX menu I get the following messages in Creo console, and the screw doesn't get inserted into an assembly:



I didn't manage to figure out why this is happening...

I checked the IFX original part and noticed it has a few features named - the axis and the under/head surface:

I named the the same in my new screw, but it still doesn't help:

So now my questions are - 

Is it possible to make this new screw which is made from scratch work with IFX? I presume it should be possible as many companies would be willing to add existing screws into IFX; can you please advise?

If not, and I need to stay on the original IFX part - what are the important features in it that need to remain unmodified, in order to not risk having the same problem as with my custom part?

Many thanks

[Ben8]

I think I figured it out. I had to assign the correct IDs in the dat file for the axis and the under/head surface. After I did that it seems to be working just fine:

[OliverGräbner]

Hi Ben8,

yes, if you change the model you may need to update the reference ids.

You can also have a look to the tutorial.

Integrating and Customizing Parts

Maybe this will also help you.

Or the chapter to customize parts.

About Customizing the Fastener Library

[Ben8]

Thank you @OliverGräbner , I managed to sort this screw. 

You are right, not sure how I missed these two lines in the manual but I did, my bad:

I have also noticed that DAT file is case sensitive - if I had the DAT file in lower case but a pointer to it in the catalogue menu txt file in upper case then it wasn't being recognized. 

Anyway, now all seems to be sorted, thank you for your support!