3D Modeling Techniques
 ZW3D Lesson Six
Top Down or In-Context Modeling
Streamlined Sketching/Feature Based Modeling

3D Modeling is the basis for our engineering. That is the only place where productivity is paramount. You can have all the PLM/MBE gurus debating data management, but it does not add one smidgeon of productivity to the design process.

Top down or In-Context modeling is the most productive feature of 3D CAD. Most systems tout this but each part is still and external part. We are talking about a single model of multi-object design environment. Both of the systems we represent offer this as the "normal" design process. Thereby increasing your productivity 20 to 30%.

In these exercises I not only focus on modeling techniques, but also on much more productive systems to do our designs. I hope you enjoy them and learn something. If you are in management, understand that all 3D CAD systems are not the same. Cutting your engineering costs is very simple. Even your legacy data is not a problem. Please feel free to give me a call. There are millions of man hours wasted every day with poor modeling techniques and ineffective 3D CAD systems that cost a fortune. Productive 3D CAD systems do not have to be expensive.

Joe Brouwer

I am doing the below assembly for an exercise showing my modeling techniques and, of course, our superior 3D CAD solutions.

3D CAD Modeling Techniques

I saw the following video challenges on linkedin and thought I would give it a try on IronCAD. I got a great response and decided to do it in ZW3D. I was very familiar with the parts and it was a bit easier.

ZW3D vs Fusion 360

These exercises started out to show the benefits of ZW3D over Fusion 360, but quickly turned into a study of modeling techniques. Take a look at all of them, they will open your eyes to a much different and more productive way of modeling. It really has more to do with modeling technique than it has to do with the 3D CAD systems. I have found that I do 3D modeling as compared to the conventional 2D sketching. Of course, having a more productive 3D CAD system doesn't hurt.

ZW3D is very similar to the Pro/e clones with a few small differences. It is very easy for those users to get up and running with ZW3D. It has a few operation that are a bit more streamlined. The benefits over the other systems are the multi-object environment (top down design) with the integrated drawing. You can do parts, assemblies and drawings in one file.

These exercises were incredibly popular and I thought I would follow up by showing more examples of this 3D modeling technique.

We will be doing a couple of parts each weekend in both IronCAD and ZW3D. I hope you enjoy these exercises and hopefully they may lead to increasing your productivity.

Please review lesson one:

3D Modeling Techniques ZW3D Lesson One

We will bring up the Center Grinder file:

Since we created this file as a multi-object the ZW3D Manager automatically comes up. It shows the assembly and all the component parts to this point.

We will select the center grinder assembly and we will see the existing parts. We will right click on the Center Grinder assembly and select "insert component". Again I want to reiterate this is not a true single model environment. Each part is still like a external reference except that it resides in the same file.

Now we insert the Pivot Arm as a new part.

Note: ZW3D's Multi-Object top down design is an incredible time saver. Especially for the individual designer. Which is most of us. Even in large companies a designer is given complete sub-assemblies to develop. The benefit of designing in top down and in a single model or Multi-object environment is that we design in aircraft position, I have been informed that automotive has car position. This how I have designed since 1986 while at Boeing with CADKEY. Top down design in the single model environment was the one reason I could not move to the Solidworks clones.

This step automatically puts us in the "edit part" mode that shows the other parts as ghosted. They are available for reference as you will see. We also have the "open part" mode which has only the single part available. You can make these external individual parts as required.

Note: I have surprisingly found that ZW3D is a superior top down design program. I have worked with many top down design packages (There are only 4 that I know of) and ZW3D is incredibly productive.

Now will will begin on modeling the Pivot Arm. We are going to design in top down or in context design. We go to the assembly menu and select Reference and select the edge of the mating part.

We insert a primitive cylinder centered on the curve and aligned to the correct plane. We size the cylinder.

Note: working with primitive is incredibly productive, i would say it increases productivity 30% and simplifies your modeling process.

We insert the next primitive cylinder on the center of the end of the existing cylinder and create it vertical. We size the cylinder.

From the center of the cylinder we will move the cylinder to the correct location. We will not select the move command we will just edit the cylinder which includes location.

We now create the plane for creating the ellipses.

We create a ellipse in the center of the cylinder. I create a line in the center of the cylinder then create the ellipse at the mid-point.


I will delete the construction line and exit the sketch. We now extrude the profile to the correct length. I have to turn it to wire frame to select the profile.

Now we create the other plane on the vertical cylinder and we have both ellipses for reference to create the arm

We used ruled surface to create the arm.

We now add the holes

We eliminate the reference elliptical holes with simplify from direct edit. Now there maybe a better way of doing this, but it does show the use of direct edit in your design process. We are actually doing hybrid modeling with this part.

I eliminate both holes with the direct edit simplefy command.

We now extend the surfaces into the cylinders .125.


Now we combine the parts using the arm as the base and the cylinder as the operators.

Now to put in the fillets.

One more little cut and we are done. We model the small slot in the bottom of one of the cylinders and we are done with this part. We will do this using the extrude wizard. I will show you my sketching technique. I projected the center circle and edited the size to 15/32, then offset that line by 3/32 both sides. I then created the circle to locate the center of the 3/32 radius then create the two 3/32 radii. 

I will just trim and delete the construction geometry. I know many of you would probably do this much different. 

We exit the sketch and we extrude to the correct depth and we are done with the part.

Here is the assembly to date.

Here is the original. I did add some dims that were not defined.

If you would like to try ZW3D, please download for a 30 day evaluation.

For more information or to download ZW3D

Give me a call if you have any questions. I can set up a skype or go to meeting to show this part or answer any of your questions on the operation of IronCAD. It truly is the very best conceptual 3D CAD system.

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If you are interested in adding professional hybrid modeling capabilities or looking for a new solution to increase your productivity, take some time to download a fully functional 30 day evaluation and play with these packages. Feel free to give me a call if you have any questions or would like an on-line presentation.

For more information or to download IronCAD or ZW3D

Joe Brouwer