Freecad external threads

[vintagengineerParticipant @vintagengineer]

Is there an easy way to create external threads.

[Thor 🇳🇴Participant @thor]

Have you checked this tutorial?

Thor

[DC31kParticipant @dc31k]

More details required.

FreeCAD is good on metric and UN thread forms. I believe NPT and BSP threads are now also possible.

On other thread forms, you have to roll your own as above. On anything with a rounded root or crest or both (e.g. Whitworth or BA form), it can be tricky.

If you want a male thread on the end of some component, use the screw die tool from the Fasteners workbench.

[HuubParticipant @huub]

I use FreeCAD for CAD CAM. Thread designing and thread milling works pretty well. I mill internal and external threads using a lathe internal threading bar. Like all tasks in FreeCAD, it takes some time to get used to it. Just give it a try.

[Paul LousickParticipant @paullousick59116]

I don’t use FreeCad but have use Solidworks for many years and seldom add thread profiles to fasteners unless for a special reason. It takes a lot of processing to generate them in a model and large assemblies with lots of fasteners can be slow to re generate unless you have a very fast computer.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

I don’t use FreeCad but have used Solidworks for many years and seldom add thread profiles to fasteners unless for a special application. Generating a thread profile in a model takes a lot of processing and a large model that has lots of fasteners can be slow to re-generate unless you have a very fast computer.

 

 

 

 

 

 

 

 

[JasonBModerator @jasonb]

Like Paul I don’t useually model full threads on my designs as they are not needed if you ar eproducing working drawings or using CNC to machine them as they slow the machine down and take time to add.

If wanting to 3D print a part with threads or use them to add some Bling to a rendering then that would be a time to fully model them.

However if by “Create” you mean just showing an external thread then FC may have an option for that. In Alibre I can choose to show a thread as a different colour or I can also select “cosmetic” threads which just give a simple “look “of  a thread and don’t us eup as much RAM. These options carry the thread spec over to the 2D drawing stage.

[Gerard O’TooleParticipant @gerardotoole60348]

I only use FreeCAD for 3D printing.  On older versions of FreeCAD  I found that method 4 in Thor’s link above “Method 4. Sweeping a vertical profile” worked fine and could be used to produce any thread pitch or profile. I have continued to use this method even though FreeCAD now comes with threading Workbenches. The tutorial shares some  limitations but in practice I find it generall works just fine and I can adjust threads to suit the printer. I am limited only by the resolution of the printer, an original Creality Ender 3 which is probably a bit basic now.

[SillyOldDufferModerator @sillyoldduffer]

Um, looks like FreeCAD v1.0.0 (current release in April 2025), has changed.

In earlier versions, I used a FreeCAD Macro called threadmaker.   No longer listed, seems to have been replaced with a workbench called ThreadProfile, which works differently.  New learning, so apologies if what follows is wonky!

My FreeCAD came with ThreadProfile pre-installed.   If not, open Tools->AddOn Manager, scroll down to ThreadProfile, and install it.    Don’t expect to make it work by randomly pointing and clicking!  The blurb includes:

Use the 2d profile object created with this workbench to create threads by sweeping it along a helix of the appropriate height and pitch. It is compatible for use in both the Part and Part Design workbenches in FreeCAD. To use in Part Design if there is an active body the ThreadProfile object will be created inside the body. Then select the ThreadProfile object and click the Make Helix toolbar icon to create a helix. A new shapebinder will be created linking the helix, and the helix will be hidden. You can then sweep it as you would a sketch using either the Additive Pipe (for external threads) or the Subtractive Pipe (for internal threads). In Part workbench you would use the Sweep tool, which would then need to be cut (if an internal thread) from a suitable object, such as an extruded hexagon.

Out of the box, ThreadProfile does V-form, buttress and bottle threads.  I believe the user can configure a thread profile to do other thread forms.  After adding the thread profile to the model, a helix is created (pitch, dia, length) and then a solid thread is created by sweeping the profile along the helix.

I haven’t explored how to apply a thread to an existing Part yet.  What follows is a threaded part being created from scratch in the ThreadProfile Workbench.

1. Start the ThreadProfile Workbench and create a new model:

The buttons ringed in green create the thread profile(s) and helix, and run the sweep.

I clicked the Yellow button to create a V thread profile, and doing so activated the helix button:

The thread profile and helix can both be edited.

Clicking the sweep button generates a 3d model of the thread:

 

That’s as far as I’ve got!  Don’t have time to dig deeper,  sorry.

Word of warning about FreeCAD!  Version 1.0, released in November 2024, is the first stable version!  Before Nov 2024, FreeCAD was very fluid, with features appearing, disappearing, and changing.  Consequently earlier internet advice and user experience may be wrong!  Make sure the advice offered applies to version 1.0!

If FreeCAD’s approach to threads seems strange, Solid Edge is also a bit weird!

Dave

 

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