How 3DPets is using NinjaFlex EDGE by NinjaTek to propel three-legged dogs!

When it comes to creating large and entirely custom prosthetics for dogs, there are few options. So how do you keep your 3-legged Rover, well, roving? Conventional methods like those used for human prosthetics require a labor-intensive, messy, wasteful, and extremely costly process — especially considering the size of some dogs. Because of this, many companies that do make prosthetics for dogs limit how many dogs they’ll serve and the types of devices they’ll make, leaving many dogs unable to get help.

3DPets, a brand by DiveDesign, was created to address this problem and lower the barrier for more dogs to get much needed mobility devices. They were able to achieve this thanks to 3D printing using extremely functional materials like NinjaFlex Edge, by NinjaTek. We recently spoke to the 3DPets team to learn about their process for creating prosthetics using 3D printing and here’s what they had to say…

So, you’re telling me the entire device is 3D Printed?!

Yes, just about! The entire harness and foot gets printed on desktop FDM 3D printers, using various flexible filaments. We begin with a mold of the dog that gets 3D scanned and brought into a custom design software for modeling the device. After it’s designed and sliced, it gets printed overnight on one of the machines. The next day it’s sanded and assembled before being shipped out.

The benefits of 3D printing for this product include:

1. Extreme design flexibility: Not only does this allow for lightweight and breathable designs, but the hardware mounting points are printed right into the product for easier assembly.
2. Lowers fabrication time: Hand-made prosthetics like this can take up to 10 hours of manual labor, whereas these take less than three since the device is primarily created overnight by the machine.
3. Wide selection of materials: Lots of variety at a small production scale and without tooling costs.
4. An ever-improving product: Since there’s no lock-in due to tooling, as the design evolves its immediately implemented.

Can you share an example of how the product continues to evolve?

Thanks to 3D printing, the product and the process evolve almost every month as we get access to new machines, materials, and other technologies. A perfect example of this is the prosthetic foot design. Our first version used a 95A TPU (most common flexible filament). It wasn’t very grippy, impact absorbing, nor did it print quickly. It worked, but not well enough. So, naturally, NinjaFlex EDGE caught our attention when it was revealed. A highly durable, grippy, and flexible material that could be perfect for the feet, and it was! After only a few design iterations, it printed four times as fast as the first generation — using less than half the material — and lasting far longer.

How does the design of the foot impact its functionality?

Design is a huge variable in the success of any printed part. You could have the greatest material, but without a proper design it’s useless. For example, even after we found NinjaFlex EDGE as the perfect material for our needs, we were printing the feet vertically on the bed. This enabled fairly efficient print speeds as the design trapped air inside and created an air cushion effect. Yes, NinjaFlex EDGE can be printed air tight, but, as soon as it was punctured with enough use, the foot would collapse.

Once we realized this, we changed the design again, this time not relying on the air cushion effect. Instead, we used a highly compressible and fast printing infill type called ZigZag, or Rectalinear, depending on the slicer used. This enabled us to truly take advantage of the fast printing and energy returning qualities of NinjaFlex Edge.

In Short:

3D printing has the ability to not only create highly functional prototypes, but also to enable products and solutions to exist that previously couldn’t. And, thanks to new and highly functional materials like NinjaFlex EDGE, combined with designing for 3D Printing, this only becomes all the more possible. That’s definitely something worth barking about.