Curved pipe (cone?) - with two different end diameters and not exactly round.

andytn.a4 · ‎06-01-2021

Extreme beginner here looking for some workflow help - a search of the archives didn't seem to turn up anything similar so here goes! I'm trying to replicate the part pictured below. One end has diameter of 2.25" and the other is 5." I didn't get very far past creating a sketch with spline and creating pipe - but it doesn't seem that I'll be able to manage the differing end diameters this way. I'm not so worried about the two 'bungs' as I am that it's not a perfectly round, curved cone - I shaded in purple the areas where it "necks" down a little bit to account for clearing neighboring engine parts. (This is a carbon fiber intake for a car). Appreciate any and all help.

mango.freund · ‎06-01-2021

hi @andytn.a4 es ist nicht das teil das sorgen macht zu kreieren. es ist vielmehr wie die exakten masse ermittelt werden koennen. kleinste winkelaenderungen fuehren hier zu einem misserfolg. ich hoffe das mindestens ein ende flexibel befestigt ist um massdifferenzen zu eleminieren. du solltest versuchen die originalzeichnungen mit bemassung zu bekommen. diese stell bitte der community zu verfuegung. greetings mango

g-andresen · ‎06-01-2021

Hi,

try this

günther

andytn.a4 · ‎06-01-2021

Thank you! That is a very nice representation - now I just need to learn how to 'tweak it.' Again, thanks for your efforts!

g-andresen · ‎06-02-2021

Hi,

1. watch the screencast

2. follow the timeline

günther

andytn.a4 · ‎06-03-2021

Excellent, thank you again.

andytn.a4 · ‎11-03-2021

It's been many months since my original post (and hours of YT tutorials later) ....life has gotten in the way - but I'm getting closer to a final version. As you'll see in the file, what I did was import a photo of the pipe first. I then outlined it, roughly. Next I created a spline down the middle, as best I could - again, just by eye - including some Z axis curvature. Then I created profiles/circles along the spline, roughly estimating and increasing the diameter as I progressed from the smaller end (2.25") to the larger end (5.0").....and then lofted, selecting all profiles. As you can see it's a bit wavy/lumpy. Short of manually adjusting the diameters of each circle to make it look smoother - does anyone have a recommendation for smoothing the shape of the body? I'm sure I've somehow made this harder than it had to be and that there may be more efficient (and accurate) methods to get to what I have below - but again, still very green here and finding my way. Appreciate any further suggestions!

g-andresen · ‎11-03-2021

Hi,

Just follow the principle "less is more".
The same applies to the number of loft profiles as to spline control points:

Only as much as necessary and as little as possible.

günther

mango.freund · ‎11-03-2021

TrippyLighting · ‎11-03-2021

@andytn.a4 wrote:

Extreme beginner here looking for some workflow help - a search of the archives didn't seem to turn up anything similar so here goes!

As an extreme beginner we can certainly provide the guidance you need to get this done, however, this is not a beginner project and you'd be skipping over many essentials needed to be successful.

andytn.a4 · ‎11-03-2021

Well that was easier than anticipated, thanks guenther.

g-andresen · ‎11-03-2021

Hi,

This already looks very promising.

günther

TrippyLighting · ‎11-03-2021

Can you share the model in its current state?

TrippyLighting · ‎11-03-2021

@g-andresen wrote:

Hi,

This already looks very promising.

günther

I wonder how you can come to that assessment without having seen the model?

andytn.a4 · ‎11-03-2021

Done.

Now, the next tweak I need is to add a small circular flat spot that is extruded from the surface of the pipe maybe 1/4", on the outer radius of the curve, near the small end of the pipe (blue circle). Were this a cylinder, I think I would create a create a sketch on a work plane tangent to the side of the cylinder and extrude it onto the cylinder. Maybe? But, I'm having trouble creating the work plane where I want it. Any tips? Hopefully I've described the feature clearly. Thanks

TrippyLighting · ‎11-03-2021

@andytn.a4 wrote:

Done.

If you are interested in how to do this properly, then you are definitely not done!

Your sketches are unconstrained and not dimensioned.
You use too many spline control points to define those curves, which is the reason the curvature is all over the place. That is one reason the surface of the tube is pretty bad.
You use also way too many loft profiles, which contributes to the bad surface quality even more.
There are 4 yellow icons in the timeline indicating warnings. Those should also be fixed before you continue.

andytn.a4 · ‎11-03-2021

"Done" as in, attached the file as requested. Not "done" with the file. 😂 But thank you for the constructive feedback.

1. Could you give me a little more to go on regarding constraining and dimensioning? More than willing to go spend a few more hours "studying" but what kind of phrase might yield the best tutorial video?

2. I'm not sure what you're trying to indicate with the red line in the photo, nor can I appreciate how the curvature is "all over the place"?? The outline of the pipe in the photo you attached was just a frame of reference for me to estimate the sketch diameters. But yes, I'm hearing you - less is more.

3. Got it. Still too many loft profiles.

4. Ok.

Thanks for time.

TrippyLighting · ‎11-03-2021

I am assuming that you want to recreate the object not just digitally, but want to create a physical; artifact.

As such, before worrying about how to model it the first task is to establish accurate dimensions.

The most important features of this object are the two openings and the angular relationships and distances between the two openings.

To establish that I'd actually hot glue to pieces of "stiff material" (foam board for example) of precise known dimensions and align/ orient them as shown in the image. Then trace the outline of the two openings. That arrangement can then be measured and the dimensions recreated digitally. The angle between the two planes is the

Then we need to connect the openings with a loft. The object in the image is very smooth and only takes three sketches. The only sketch that could be a 3D sketch is the center rail. The 2 openings would usually not be in one 3D sketch but in two different 2D sketches. I simply created this loft to show what "less is more" actually means 😉

Model is attached.

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Curved pipe (cone?) - with two different end diameters and not exactly round.

Curved pipe (cone?) - with two different end diameters and not exactly round.

Curved pipe (cone?) - with two different end diameters and not exactly round.