Error In Creating Thread?

[spinecad]

I will be away from my AutoCAD computer for a week or so, but it is critical how you line up your profile with your helix and your profile must be created in such a way that it does not result in a self-intersecting sweep. My guess (without seeing the file) is that is your problem.

 

OK, I am waiting for the answer upon your return.

[SLW210]

Sweep works here. Not sure what you want, I just Sweep> clicked on the profile> Enter> Selected Helix.

 

[tonyj]

Spinecad, see attached image and drawing.

Basically all I done was took your profile and shortened the back part that was 7mm long to 6.65mm long so as not to have it self intersecting as JD Mather pointed out. That way you can do the sweep along the helix.

helix error.TM.dwg

[JD Mather]

spinecad - did you ever get this figured out?

I asked for thread specifications. This would be the standard threadform information. You have 53° angle. What specification are you using?

What is your intended pitch?

 

You need to use logic in creating geometry in it's simplest form. Break out primitives like cylinders and use Extrude, Revolve, Presspull or the Cylinder Primitive.

In this case it only adds to complexity to try to sweep this red geometry area on a helix when the end result would be a cylinder (thin wall pipe).

 

Forget the actual thread feature of the part for a moment, if you were going to create a thin wall pipe - you would never do it by sweeping a rectangle on a helix. Keep it simple. Separate the various geometry shapes into their most basic forms.

[tonyj]

 

Forget the actual thread feature of the part for a moment, if you were going to create a thin wall pipe - you would never do it by sweeping a rectangle

 

That's true, and a good idea. But when you go to do the thread part, by sweeping along a helix, would you have to slightly scale down your profile to stop it intersecting with itself, or would this matter seen as the ends would be tapered down to nothing. I'm not near my Autocad computer.

[JD Mather]

...profile to stop it intersecting with itself, ....

 

As indicated previously - that is the major problem, but before moving on to possible solutions to more complex problems the most basic geometry should be recognized and understood.