Calculating surface are of a threaded hole?

[AN_9728684]

Hi all, 

I would like to calculate the total surface area of a part that has threaded holes. 
By default, Creo only calculates the surface area of a threaded hole by only considering the hole's minor diameter.  

This causes the calculated surface area in Creo to be approx. 20% lower that the actual surface area of a threaded hole. 
Therefore,  for a part with hundreds of threaded holes there will be a significant difference between the actual surface area vs. the area measured in Creo.

Is there a way to calculate the real surface area of threaded holes. 
P.s. making helical sweep for each of the holes could be quite time consuming and possibly make model heavy to load.

[Dom_CHENTRE]

Hi, my first idea...
Leave all your assembly with "simplified" threads.

On just on hole, create a real thread (helical sweep).

Then calculate real surface vs approximate (cylindrical).
So, you can define a parameter for this ratio.

And then, you can calculate approximate surface and apply to them ratio for having real surface.

[Pettersson]

Here's one way. You could do this as a mapkey to automate it.

Make a search. Search for quilts by feature with type = Has thread. Select all results. This will select all thread surfaces.

With these quilts selected, run an area measurement. This will give you the total area of your thread major diameters.

Save this as a feature.

Make another area measurement that collects the solid area. Save this as a feature as well. (You can get this from a Mass Properties feature, and now you get parameters for mass and volume, as a bonus.)

Make a relation to the effect of total_area = solid_area + 0.2 * thread_area.

Search for the measurement features, select them and move them to the footer.

Unfortunately there's no way I know of to save the query in the measurement feature. This means it has to be updated if new holes are added. You could probably have a mapkey thaty deletes the measurement feature and recreates it, which can then be used to update the part and should be run any time you add new threaded holes (and probably when you remove them, too, since your existing feature will have missing references).