By Ryan Dark

Printer tips for our Stratasys 3D printers get disorganized quickly in the drawer near our machines. The tips are packaged in cylindrical canisters that look similar to old-time house fuses, and they all seem to bounce around the drawer every time you open it. Joshua Zuniga, our rapid prototyping technical manager, asked me if I would design a solution for him.

If at first you don’t succeed, try and try again
The first design that I made had a box-shaped case around the canister that holds the tip. I couldn’t tell you why I did it that way except it’s kind of just my natural predisposition. It goes something like: “Hey, we need to organize stuff … so we’re making a box, right?”

I designed the first iteration and printed it off and had Josh look at it. He said, “First this uses way too much material; it won’t be very fast to print, and it’ll take too much time. Can you chop off as much material as possible?” Fantastic, I thought, I can do that.
Massively overbuilding it was my first mistake—been done a million times in the history of design, right?

All things isotropic
The second mistake involved the FEA analysis on the clips I was designing. I wanted to be sure the clips securely held the printer tips, keeping them from falling back out into the chaos of the drawer.

The issue I did not take into account for the analysis is that rapid prototyping does not have isotropic (uniform) properties. Once printed, the little clip arms that were going to hold each printer tip case were so thin that they became practically hollow on the inside.

The new clip arms shown in the FEA image to the right are five times stiffer than the original design, and the arm tips curved around slightly further for a stronger more secure grip.

Third time’s a charm
The next design was two or three times thicker, and I “chopped off” (technical term that I learn from Josh) over 90% my original design, only the clip itself remained. Then, I patterned it so I could have multiple clips side by side—kind like of a bandolier of print tips.

Design is an iterative process. Because we have the printer in-house, it took only a few hours to make changes. If we had outsourced this job, it would have taken much longer, especially with the changes.

I developed the new design with no overhangs, so I could print the part without the need for the dissolvable support material, which both sped up the process and saved a ton of material. I also made a flat back so you can tape it on the back of your printer or just stick it in a convenient place inside of your printer.

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