Describe the part. How is it used? How is it currently manufactured?

The engine bolt nut protector is designed to protect the bolts used on the vessel engine from dust, grease, rust, and physical damage. They play a vital role in the engine’s well being because a damaged bolt can compromise maintenance schedules and engine performance.

As these bolts are a highly specialized and an expensive part, they must be protected using caps that are traditionally made of hard or semi-flexible plastic. However, with time and the constant exposure to high temperatures and physical stress, the caps usually end up breaking or cracking, compromising their protective function. Also, as they are small, it’s not uncommon to lose them during a routine maintenance procedure.

What are some of the challenges in sourcing this part today?

Usually bolt protectors are a simple part to source. That being said, engine bolt protectors are not easy to source since they have rare sizes and materials. If we also factor in that the lifespan of an engine can be several decades, it is not uncommon to see vessel engines with spares (including bolt nut protectors) that are increasingly difficult and expensive to source every year.

Why would digital manufacturing make sense for such a part?

Bolt nut protectors don’t have a life span per se, meaning that they are not replaced on a scheduled basis; but instead, they get replaced when needed, making it hard to maintain inventory. Many times, sourcing these parts is considered so much of a hassle that they just aren’t kept in any inventory. That’s why the crew protects the bolts by using alternative solutions, such as taping them. However, this is only a short-term solution that offers no guarantee of protection for the bolts.

Additive manufacturing technology provides an important advantage because it can improve part performance with no relevant added cost. For instance, while we design, we can easily add ribs or textures on the exterior of the part to increase grip. We can also add a female thread to the inside so the part can be more securely fixed and protect the bolts. Both of these examples are improvements asked from vessel crews that we can perform. Additionally, we can label the protectors with actual bolt measurements and thread type.

What are some of the technical challenges in digitizing and manufacturing this part?

There are two main technical challenges to consider when working on these parts. First, the tolerances need to be accurate because if we make the part too loose, the protector will “wobble” around the bolt. This will reduce its protective efficiency and make them easier to fall. Furthermore, the bolt protector will need much torque to be threaded to the bolt causing damage to the bolt and reducing the bolt protector life.

The second challenge is the manufacturing material, because the part needs to perform at constant high temperatures and contact with hot metal. To solve this, we need a 3D printable polymer that can resist physical impacts without losing its physical properties. Consequently, we have decided to use a composite carbon fiber nylon with a working temperature that is higher than basic nylon. Also, carbon fiber works as a matrix that increases the part integrity. Simultaneously, nylon, thanks to its relative flexibility absorbs impacts without breaking or cracking.

How do you see the future of additive manufacturing?

In one word: exciting. Additive manufacturing is one of the pillars of the fourth industrial revolution, which means that it’s a growing industry that will heavily dictate how our products and services will be transformed in the near future. Day by day, this technology keeps improving and innovating in its processes, materials, software, and services. With such innovations, we have new opportunities for applications for heavy industries.

As the concern about the environment keeps increasing, additive manufacturing will heavily reduce the carbon footprint needed to operate and maintain heavy equipment with a minimalistic supply chain.