Weekly Challenge Group

It was a bit tricky, but I got it. :)

My goal was to make this model as efficiently as possible. Total time from firing up Inventor was 22 minutes. Secondly, my aim was to place the flange faces on two of the base workplanes. This would make subsequent constraints in an assembly a little easier. No dimensions are fudged. All dimensions are exact or parametrically derived.

I made a couple of assumptions.

1. The 50mm pipe radius was a true radius and not the apparent projected radius. If it was projected then that would make that pipe a section of a spiral. Something that would be impractical (but not impossible) on an actual manifold.
2. Since there is only one line of tangency between the 50mm radius and the 80mm radius, there is no straight section of pipe there. That means the angle of the 50mm section must be adjusted (parametrically) to align these two sections exactly.
3. The only dimension guessed was the angle of the triangular flange. I placed the upper edge 15° from horizontal.

It was a good challenge that turned out to be simpler than I originally thought. I too needed more than 22 minutes but practice makes prefect, and now I can strive to improve my speed.

It was a good challenge that turned out to be simpler than I originally thought. I too needed more than 22 minutes but practice makes prefect, and now I can strive to improve my speed.

The challenge failed.

It's hard for beginners like me. I don't have a train of thought.

3 Hours

Where does the double tangent line come from? On the original challenge sketch it only has one. I see this same double tangent on other's models.

The key to the whole design was this first sketch. It serves as part of the path for the sweep and sets the angle of the 50mm curved section. Note the odd reference angle but it produces a perfect tangency.

[edit] The way I have it only works if you do a true 50mm radius and not a projected 50mm. If you do a projected radius then the 50mm dimension in my sketch would be the vertical distance and not the angled distance. (Not sure if that makes sense.)

A projected radius adheres strictly to the challenge sketch but it produces a pipe with a spiral shape rather than a simple radius. That's something unlikely to be done in the real world. I think the way you have your path generated, you used the projected radius.

If you do a projected 50mm radius then it would look something like this. Note the different reference angle.

This is with the original drawing overlayed on the projected dimension. Doesn't match.

And with the true radius. Looks good.

Okay, I'll try it as you say, thanks.

It's a bad drawing to start with. If there are important factors the drawing needs to define them. If the drawing is "good enough", so are the models we make from it.

If you made something that looks remotely like the print you passed.

Most challenges like this are meant for 3D CAD practice. Not manufacturing a perfect part.