Reverse Engineering in the Dental Industry CADimensions

You may have heard that the dental industry is one of the largest users of 3D printing in the world. Mass customization of aligners and other dental tools have made adoption of the technology a huge financial win. My dentist, who also happens to be my dad, had a different 3D printing request. A clamp component that holds up a small working table failed, smashing it in two. As a temporary solution, his staff super-glued the clamp back together. My dad reached out to me to see if I could print the component as the manufacturer was no longer producing that part.

Reverse Engineering the Clamp Component

I handed off the part to our SolidWorks team so they could reverse engineer it and run a quick stress analysis to see if making slight modifications to the design would affect the functionality of the part. Fred, one of our support engineers concluded that our standard ABS material would do the job, even with a sparse printed infill.

Reverse Engineering in SolidWorks

Dental Clamp Component 3D Printing Set-Up

I brought the file into GrabCAD to set up for printing when the SOLIDWORKS model was complete. I was able to make use of some of the cool new features within “Advanced FDM Mode” to modify the part. First I used the “Apply Insert” feature to modify the four holes at the base of the part to accept #10 – 24 Long heat set inserts. The program automatically changes the hole diameters to the appropriate size and adds additional contours to the area around them to ensure a proper fit.

Next, I used the “Avoid Seams” feature to relocate the print seam off mating surfaces and off surfaces that came in contact with the chair. The green surfaces below show the changes.

GrabCAD Print Advanced FDM Mode

I sent the job over to our Fortus 450mc when I was happy with my settings. Using a sparse infill pattern and 0.013” layer height, the part was complete in less than 3.5 hours. When the print finished, I threw it on our wash tank. It only took 4 hours to completely remove the soluble support from the insert holes.

Next up was placing the heat set inserts. We did not have a soldering iron to heat the parts. We ended up using a small blow torch to get the metal inserts hot enough to set in place. I wouldn’t recommend using this method as getting consistent heat through the parts was rather unpredictable.

Final Results

With the finished part in hand, I stopped by my dad’s office to help install the new part. It fit well and was able to hold the table and tools plus a small amount of additional weight. For a better fit, the radius of the new part could have been slightly bigger.

I also found out that the existing half of the clamp had a small rubber sheet that prevented to part from sliding down the pole. The second rubber piece must have been lost when the original broke. The part is currently holding up to the job. If anything, it could be immediately improved it would be adding more friction between the part and the pole. My dad was happy with the outcome and I look forward to better optimizing this part in the future.

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