Abstract Chat about 3D Modeling Techniques With Strong Feelings and Emotions

[CI]

2D Drawing:

Here is an engine with its 2D drawings.
Each drawing was created in 2D Autocad, basically by looking at each face of the engine, and drawing the visible edges.

The problem with 2D engine drawings (many problems) for use with engine work, is that if any one view is changed, say in a front view, then that change may or may not affect the other drawing views.
So it becomes a matter of making a 2D change, and then playing whack-a-mole trying to change all the other views accordingly.
Inevitably one or more views will be wrong after a few changes.

There are no automatic relationships between the views, so changing one view does not update any other view.

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[CI]

Parametric 3D Modeling:

With 3D modeling, the approach I use (there are several approaches, but this is the one I use) is to create one 3D model for each part, one at a time.
Once all of the 3D models have been created, then they can be assembled in the 3D program in an "assembly" file, not to be confused with a "part" file.

The beauty of parametrics is that any change to any model immediately shows up in the assembly.

2D drawings can be created on a 2D sheet, using a "drawing" file, not to be confused with a "part" file or an "assembly" file.
You can drag a 3D model onto the 2D sheet, and create the base 2D outline, and then the shape can be dragged in multiple directions to create left, right, top, bottom, isometric, etc. views.
You can change what is seen on the sheet from rendered, to hidden-lines-showing, to hidden-lines-hidden, and several other options.

Any change to any model is automatically reflected also in all the associated 2D drawings, and the dimensions will automatically update if you set them up correctly.

You can also create things like Bill of Materials, exploded views that you can snap expanded and then un-expanded to the original assembled position, etc.

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[CI]

Extruding a Cut:

You can draw a circle, or any shape on any plane, and extrude a cut through any other previosly extracted shape.

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[crueby]

Great  stuff CI!

[CI]

Saving Screen Captures:

I have started saving screen captures ("printscreen button, paste into a photo program) after each step, for complex parts.
Sometimes I have to back up a few steps, or I can't work on a model for a few days, and screencaps gives me a paper trail of the steps used to create the model.

There are often multiple ways to do something, and I tend to forget over time which method I used.

Here are the screencaps for creating a Lunkenheimer carburetor.
The inital sketch was created by tracing over a side view of a Lunkenheimer carb.

I started with roughing out the body, and then added and subtracted items, to make the complete carb.
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[CI]

Great  stuff CI!


Thanks cruelby.
I hope this tutorial saves some folks from the trama I experienced when trying to rewire my brain to 3D modeling.

This tutorial is very simplistic, and people may find it too basic, but these are the concepts I struggled with in the beginning, so I figure that there may be others like me who want to learn 3D, but don't really know how to begin the process.

Hope this material helps some folks.

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[CI]

Lunkenheimer Carb (Continued):

You can add a new plane anywhere, and start sketching on that plane, and perhaps extruding back to the surface of an existing shape.

It took me a while to figure out how to insert a plane, and even longer to figure out how to insert and rotate a plane to the desired angle.

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[CI]

Lunkenheimer Carb (Continued):

If someone had asked me how I made the carb model, I would have no recollection of the details, without these screencaps.

[CI]

Lunkenheimer Carb (Continued):

[CI]

Lunkenheimer Carb (Continued):

I like to use various colors, and I think it added 3 dimensionality and clarity to the model.

You can cut a section on a part to see what is inside.
You can suppress the section by toggling it on and off.

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[CI]

You can toggle on and off any piece of a 3D model.

You can change surfaces to translucent, if you need to see inside of the model.

You can toggle between a rendered model and a wireframe model, with or without hidden lines.

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[CI]

Some Dake screencaps.

[CI]

A steam ship side beam engine (the Mississippi).

This engine is very similar to the Pacific engine, and perhaps designed by the same engineer.

All the models in this design were created from the original 1840 naval drawings.
Lots of challenges in these models.
Still not done with this engine.

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[CI]

More Mississippi side beam models.

[CI]

So every one of these 3D models were created by a dumb old guy who only knew 2D autocad, and NEVER thought or dreamed he would ever master even the most simple of 3D models.

But the fact stands, you can learn 3D modeling at any age, and while you may have to do a bit of brain rewiring, 3D modeling is no more difficult to do than 2D CAD once you understand the concepts of 3D modeling, but 3D modeling is a lot more fun visually for sure than 2D work.

And a bonus is that you can 3D print these models, and make patterns, and then make castings, so not just a pretty picture.

I am a poster child for "dumb old guy learns new 3D modeling tricks".
If I can learn it, anyone can learn it.

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