Modeling NPT threads for 3D printing

[mark_mckann7LD]

I have a part that I'm trying to 3D print with some NPT threads, and I'm trying to model the threads rather than need to tap them afterwards. The hole command has settings for NPT threads, but it doesn't look like it actually models them. There doesn't seem to be an option for that particular kind of thread in the thread tool. I've found a workaround on these forums by using the combine tool on the corresponding part downloaded from McMaster, but I'm wary of relying on that in case I need to create NPT threads and McMaster doesn't have the corresponding part available. 

The last possible option I've come across is custom .XML files that have the thread information that is inserted into an installation folder, but I haven't had luck finding one that has NPT tapered threads. 

Has anyone come across any .XML's that would have this information, or preferably some already existing functionality?

[MRWakefield · Accepted solution]

As you've found, this functionality doesn't exist in Fusion (yet 🤞). It has been discussed many times on this forum over the years but we still seem to be no nearer to getting it. Unfortunately there's no provision in the XML files for a tapered thread so even if you had all the correct data you still wouldn't get a tapered thread this way. There's an NPSM thread file here if it is of any use. It's the same as NPT but without the taper. It's quite normal to use a straight threaded part with a tapered mating part but if you want it to seal you'd probably need to add some PTFE tape or sealant. Even if you 3D printed a tapered thread you'd probably need some kind of additional sealing on it anyway.

Hope this helps.

[etfrench]

You can model NPT threads using a Surface workspace helix (Sweep with Taper and Angle):

Note: Image just to show technique.  Values are not accurate.

In the Solid workspace create a Plane on Path on the edge of the surface sweep.  Add the thread profile to a sketch on that plane.  Sweep that on the same path.  You may need to add guide rails.

Insert Derive this into your models.

[chuck767]

is helix on the hobby version 0f 360?

[Leo_Dyn]

Another method that has been mentioned over the years on this forum is to go to McMaster and download the model of a part that has the pipe fitting with the correct thread. Then you can modify that model and/or cut and use the portion you need in your own parts.