real threaded holes

[teoadams]

I need to create a model with real threaded holes profile (holes can be metric or NPT or BSP) to be able to make a real section to be inserted in a catalogue.
The only way I found is subtracting material with elical profile but I need everytime to create the correct profile depending on the type of thread. Any other ideas?
thanks.
Teo

[John Scheffel]

The only way that I know to create real screw threads is the Add/Remove Helix operations under the Freeform menu which require drawing the thread profile. But it sounds like you found that option.

Making it easier would require some type of 2D thread profile library or a method of generating thread profiles by type and parameters. I'm not aware of anything like that for Modeling but maybe some other CAD application has it. You might be able to find a library of 2D thread profiles in DXF format, convert them to MI format, then import them into your work plane.

[MichaelA]

this is something that could be done via a custom LISP script, input the parameters and have it generate the helical surfaces. don't know if the german site (http://osd.cad.de/index.htm) has a script available or not, haven't seen anyone else with it. There are scripts for generating springs which could be used for a starting point and I have seen scripts to change diameters and such of holes or shafts to the correct size depending upon the thread size (see the german site for that one).

The main thing to watch out for and why most of use don't do this, is file size. helical surfaces add a lot of data to your files which makes having true threads on parts impractical IMHO.

Michael

[gmatelich]

I often don't mind the minimal (in my experience) performance hit for using helical features (particularly when I compare it to the doggy performance I see with Solid Edge or SolidWorks even without helical features). The other issue is creating a true thread form. Occasionally, I'll spend way more time than is justified to research and draw a true thread form - it would be wonderful to have it coded into a lisp macro. The same is true for gear profiles.

I would love to see CoCreate extend the display options associated with the Machining Threaded Hole tools, so you could optionally display threaded holes as a semi-transparent cylinder representing the minor and major diameter of the hole, or as a true helical thread form in addition tothe current blue faced hole. This could also be an option in Annotator to show true thread form. Obviously, I'd also love to see this carried forward to external threads.

[Wolfgang]

Originally Posted by MichaelA

don't know if the german site (http://osd.cad.de/index.htm) has a script available or not

Please use, http://osd.cad.de/index.en.htm as start point for non-German reading people. At least the index is translated completely, even when the detailed descriptions are partially (to be honest: in the majority) still available in German only. Translating progress is less right now, but greater than zero

Real thread: no: there's nothing available on the german osd.cad.de neither. And if thinking about the real geometry of thread profiles and in addition I think some geo profiles of inner threads are different from outer threads.. so this is very detailed stuff and I wonder if someone picked up the effort and created all that profiles as 2D data.

oli:sd-define-thread already lists 15 different profiles (ok, lets subtract 3 'fine' threads).