Reverse Engineering & 3D Printing 101

Making The Most of 3-D Printing Technology through Reverse Engineering.

Recently Baklund R&D had a customer send a request for some reverse engineering. There were 9 different part numbers in the RFQ. The customer asked us to start with one part, to see what we could do and then we would be quoting the other eight.

Of course we said yes to doing the job. This type of work is right up our alley. This work is the perfect blend of mechanical & design skill and 3-D printing. Even though it was only for one part, measuring the part and getting all the dimensions into Solid Works and designing it still took four days.

The part was very difficult because of the multiple angles and as you see in the pictures, there were compound angles.

Some people ask, “Why do you need to reverse engineer a component?” That’s a really good question, because there’re many reasons to reverse engineer something. Sometimes the part is out of date and not produced by the original manufacturer. Sometimes it was a design made at the company, and their filesystem is not up-to-date or maybe crashed and they lost some models. Most the time companies call for reverse engineering because it is a component that someone in the machine shop made years ago, to solve a problem or fix a machine, and that person is no longer there or the company does not have their internal machine shop anymore.

Aaron Weikle,

Who is a machinist and designer at Baklund R&D was handed the task of measuring and modeling this part. (Aaron earned his Reverse Eng & Design Level I Certificate on this job.)

The tools used for this project:

1. A 12 inch scale

2. An eight and 12 inch caliper

3. Solid Works on a laptop

4. Insight software on laptop

5. Stratasys 400MC FDM printer

6. Skilled machinists/designer/ FDM machine operator, who understands growth factors and shrink rates in the 3-D printing process, so that you come out of the machine with a functional part based on your design.

The customer sent us a machined part that was failing in some high stress areas. One of the benefits of designing for 3-D printing is that you can compensate easily for areas that have high stress or high wear in your design and it takes virtually no extra time to do; and the cost of material is minimal.

As you can see in the picture above, the part is machined from White Acetal, and has been damaged. The customer has epoxied it to try to strengthen the weak areas. However, due to the nature of the way this part is used, the epoxy areas have broken through again.

The first phase of the project was to take measurements.

As Aaron begins he starts with the base and the simple segments of the component. He needs to start with the foundation and build his model properly in Solid Works, just in case he needs to make any changes to previous features. If you design it correctly from the beginning, changes are easier to make in later iterations.

In the picture above, you can see Aarons foundation as he is continuing to measure the part and add other features.

In the picture above, the part is almost completely designed. This picture was taken on day three. This was a four-day project to measure and design this part. Reverse engineering oftentimes is difficult, depending on the amount of wear on a part or features that customers want changed or strengthened. In the picture below you will see the round feature coming out of the part is at multiple angles; we call this a compound angle. This type of feature is very difficult to measure and replicate and to make accurately.

In the picture above it looks like Aaron is completely done. I remember this stage because Aaron called me over to the Baklund R&D on floor design station. He was very proud of his reverse engineered and designed model. With the design done, it was then time to turn this model into an STL file. In the picture below you will see the layers of model and material that are showing up in the insight software that runs our Fortus 400 machine.

Once the model is in STL file format, it is taken into the software for the 3-D printer. After that the machinist slices the part, sets up support, adds the tool paths, evaluates the material that he wants to use, and checks to make sure the part will be built properly. He can then send it to the machine. In the next three pictures you’ll see different segments of the timeline in the build. The white material is support material. The black material it Is model/The actual part.