Path must not be a null shape (2024)

Hi,

I am trying to create a subtractive helix, however I keep running into the error mentioned above.

I have two versions of the project, one trying to subtractive and the other merely trying to sweep across the helix to later on perform a cut with said shape. However both result in the same error and i don't know how to correct it without having to restart the entire project over again. There are other components to this, however I have chosen to just include the part I need to thread.

Sweep and cut version:

https://easyupload.io/gzcrff

Subtractive sweep parts WB:

https://easyupload.io/cc2bxs

Any advice would be greatly appreciated. I am still relatively new to freecad for the time being

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smktec wrote: ↑Sun Apr 02, 2023 8:30 amyou should use sub shape binder to import the path into the body. Then simply edit additive pipe and replace "object" by Binder and it works.

Can you please run CheckGeomtry with BOPCheck on the Helix? Here I had fixed the existing ShapeBinder and CheckGeometry runs endless.

A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.

@chrisb

If the height of the section is too big, how would I go about addressing this then?

The dimensions required for the helix are as follows:

Pitch: 0.04545
Height: 0.73
Radius: 0.875248

@smktec

Thank you very much for that. Any advice where I could learn about your process of doing that? Obviously I can reverse engineer it but just for future purposes?

Thanks

oliverspozi wrote: ↑Sun Apr 02, 2023 9:00 amIf the height of the section is too big, how would I go about addressing this then?

You can either use an expression where you subtract e.g. 1/100mm (don't know how this would be in imperial miles) or you use an external reference.
I see also that the section has a peculiar angle with respect to the helix. I would rather place it at the origin or attach it properly to the ShapeBinder, which as an additional benefit would simplify the sketch.
Ask back if you need more information or the model.

A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.

@chrisb

I actually see what you are talking about with regards to the angle. Thanks for pointing that out.

I am going to redo the helix instead and see what happens. Do you know how the other gentlemen linked the Shape Binder bits? I have absolutely no idea on how to do that.

I ended up just doing your version of the helix with the respective radius and it worked out a lot better than what I was doing tbh

@chrisb

Some advice, so I am uncertain which radius to use for my sketch to get the correct helix radius. The dimensions are:

Major DIA: 1.78
Pitch DIA: 1.7505
Minor DIA: 1.7242

I feel it should be the Major DIA / 2 but just want to confirm.

The sketch is below incase you need further clarification

https://easyupload.io/5vmjfz

oliverspozi wrote: ↑Sun Apr 02, 2023 9:38 amSome advice, so I am uncertain which radius to use for my sketch to get the correct helix radius.

I can't tell, because I don't know what you want. Is the outer diameter or the inner given? What is it for? It is often helpful so see more of the big picture.

A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.