cosmetic or helical sweep cut for threads

[mudassirkhan]

Hello Everyone,
Can anyone tell me the advantage of making threads by helical sweep cut rather than using cosmetic thread option. I am having a debate with my project manager. He wants all the threads to be done by helical sweep cut. I know this will make the model/assembly too heavy but he is very adamant. Can you guys give me some clues so that i can convince him to use cosmetic threads. Thanks in advance.

 

[AHA-D]

In my Solid Edge job I have never ever created a real thread by helical sweep, in my ProE job I have never used a cosmetic thread ! It all depends on the demands. You make real threads when you want to make images that show the product "as is", meaning you zoom in real close and want the thread to be visible and shaded as in real life. In all other cases it is far better that the production drawing shows what is necessary and the model is as simple as possible.


Imagine what the assembly of an oil refinery complex would be if each and every bolt were created "real" : run ProE on IBM's "deep blue" ???

 

[dr_gallup]

It mostly comes down to overhead. Make a model both ways and compare the file size. Then look at the number of fasteners in your typical assembly. Do you have enough compute power (CPU, RAM & Graphics) to handle all the extra overhead?

Also, are you driving CNC equipment with Pro/MFG? The post processor will know what to do with a cosmetic thread, will it know how to program the helical sweep? It may try to single point the threads instead of using a tap or die.

The one advantage to helical sweep is you can eliminate the assembly interference that you get with cosmetic threads. However, you will have to control the rotation of your fasteners to get the threads properly aligned. Assembly creation will be significantly more time consuming.

 

[Dell_Boy]

An alternative to a helical sweep is a linear pattern of rotational
cuts. Not quite as good looking as a rotational cut but not as costly
in terms of CPU power to crunch it.



IF you had a few very large fasteners you may want to consider cutting
the threads but to be truly useful it should have the EXACT thread
profile and runout.



With small fasteners, the lines on the drawing are going to merge into
a blob so I really can't see the point of cutting these threads at all.



For me a typical assembly has way too many fasteners to consider
anything except a cosmetic thread and even these are layered out 95% of
the time.





DB


Edited by: Dell_Boy