MBD is Here: 10 Reasons Why Everyone is Moving Away From Traditional 2D Drawings

Moving from 2D Drawings to 3D MBD PMI models.

When SOLIDWORKS came out in the mid to late 90s, 3D computer-aided design (CAD) was considered to be just a fad.  Everyone worked in 2D, and that was the staple of engineering programs.  Now, 20 years later, 2D is a thing of the past (for most), and 3D is the king when discussing CAD.  Whenever I mention to someone that 2D drawings are going away very soon, I always get the same response, “They will never go away”.  How about I explain why traditional 2D drawings are flawed and the benefits that Model Based Definitions (MBD) can bring to you? 

If you are not familiar with MBD, its definition is "A 3D annotated CAD model and its associated data elements that fully define the product definition in a manner that can be used effectively by all downstream customers in place of a traditional drawing." I will let you determine if 2D drawings will never disappear.

Reasons 1-5: Why the traditional 2D Drawing Process is Flawed and How MBD Addresses This. 

1. Drawing Creation time for Full Specification

We can all agree that the time it takes to create a drawing is more than it should be, sometimes more than the model itself.  Some of our customers are already supplying the CAD model to their contract manufacturer and creating a dimension drawing.  Even if they are not creating a limited dimension drawing, manufacturers are requesting a STEP/Parasolid/IGES at a minimum.  Full specification drawings should be a thing of the past; limited/reduced dimension drawings are where we should be right now as a whole.

2. Fat Finger data on the Drawing that does not make it to the CAD model

When an incorrect drawing needs to go out it’s very easy to override the value and continue on.  That value never makes it to the model, and in the next revision, it can easily be overlooked.  This can result in getting a whole run of parts back in and being incorrect.

3. When was the last time college taught proper 2D Drawing etiquette?

I have mentioned this to some of our customers and generally get a good laugh out of them. It’s no secret that those coming out of college don’t know how to properly create GD&T, supply the correct manufacturing information, or even read the 2D Drawing. I am in my mid-20s, and traditional 2D Drawings make absolutely no sense to me. Moving away from 2D is just where the workforce wants to go naturally due to this problem.

4. Manufacturing Recreates the CAD Model in 3D Anyway

With tools like SOLIDWORKS CAM being included with every seat of SOLIDWORKS manufacturing is not more reliant upon using the model than before.  Using the 3D model for manufacturing has many benefits, which is why our customers recreate them if need be.  Why is this even a thing?  We design models in 3D; why detail a drawing and then have your manufacturer recreate it? A lot of wasted time on both ends.  I understand protecting Intellectual Property, but sending a full specification drawing for the manufacturer to build your part is no different than sending the model.  They recreate the model anyway.

5. Misinterpretation of 2D Drawing

If you have ever looked at a 2D Drawing, you know there have been dimensions, notes, or GD&T that you have no idea what it’s referencing.  It’s really up to how the viewer interprets the drawing and what they see.  This can lead to a lot of problems down the road.  Wouldn’t it be really nice to be able to select the dimensions and highlight the associated faces?

Reasons 6-10: Benefits of MBD over 2D Drawings

6. Decrease Delivery Times

As I mentioned earlier, recreating a 2D Drawing into a 3D model takes time. If the model is supplied, it saves time for obvious reasons. Utilizing MBD also has some advantages over just supplying the model. SOLIDWORKS CAM's Tolerance-Based Machining features allow for additional functionality that isn’t present with 2D Drawings. Also, if you don’t have to create a full specification drawing, that will save time on the front end.

7. MBD Increases Efficiency

How many times have you heard, “The drawing needs to be updated”? Probably too many to count, I imagine. MBD means model-based, so everything is located within the model. There is no need to update something other than the model. This makes it easier for everyone involved, and the process is more efficient this way.

8. Reduce Scrap and Rework

Eliminating errors when interpreting a drawing is a huge factor in reducing scrap.  Not only does scrap cost money, but it also costs time, which cannot be made up.  Not only do errors occur reading drawings, but if someone is completely recreating your model to manufacture, you can almost guarantee it’s not exactly the same.  This leads to non-conformance parts, and the paperwork begins.  With MBD, any dimension, note, or GD&T that is selected highlights the associated faces, so there is no way it can get misinterpreted.  Manufacturing to the model has many other benefits, like being able to see if the machining tool will gouge the part, for example.  Being able to determine this before any chips have been made will greatly reduce the scrap if not completely eliminate it.

9. Improved Utilization of 3D Assets

With tools available like TolAnalyst, Tolerance Based Machining, CMM programming, GD&T checks, and many more when using MBD, only the 3D Model can be utilized more effectively.  This allows more functionality into your design models that you can’t get from a 2D Drawing.

10. Moving Towards MBE

Continuous Improvement Initiatives are looking at MBD currently and moving to this technology opens doors for jobs down the road.  The Department of Defense (DoD) is requiring that suppliers are MBD compliant which not only makes you more competitive in today’s marketplace but allows more easy growth in the future.  Software companies today are recognizing that MBD is the future and will continue to release new technology supporting the movement.  Getting on board now or very soon will allow for easier growth in the future.