Where Did You Get Those Doors?
Faced with a frenzied desire for aftermarket modifications, manufacturers of Jeep accessories are in a constant battle to come out with new and innovative products. Stemming back to the ‘40’s, the Wrangler is one of the most iconic vehicles in American history.
A Jeep Wrangler without its top or doors is not an uncommon sight, in fact, they were purposely designed to be removed, and it's been that way for decades. It’s truly an experience to have all of that fresh air coming through, having your feet resting outside the cabin, and throwing that “Jeep wave” up when another Wrangler rolls by. If you’ve never experienced it, add it to your list. These fun features have obviously lent themselves to many aftermarket accessories for these iconic trucks — from bikini tops to steel tube doors the options are far from limited.
To keep up with demand from hard-core Jeep-mod enthusiasts, manufacturers are looking for new ways to manufacture. And they want solutions that not only make financial sense, but also deal with supply chain issues the world is currently experiencing.
With these challenges in mind, we humbly declared 3D printing to be the natural solution! And while it was clear to us that high-flow, large format, pellet-based 3D printing was the way to go, we still had a fistful of hurdles to clear. In addition to finding the perfect material (obviously the most important piece of this puzzle), we had to keep in mind speed, cost, reliability, and dimensional accuracy. This created quite a dragon to slay, so we suited up and got to work.
Materials Selection is Critical
First up was the hunt for a suitable material because let's face it: without the right material this whole idea goes right down the drain. 3D printing at this scale — with such a large flat piece — already had its red flags. Adding a requirement that it be tough enough for an off-road automotive application, set off alarm bells that still have our ears ringing. Needless to say, making the correct pellet choice was critical.
So, ignoring logic we began our quest for the perfect material. We needed something that could withstand a beating and still be easy to print...not an easy ask. To start, we looked at pellet materials available for 3D printing. After a few days of searching and with a limited variety of options available, outside of your traditional PLA, ABS and Nylon, we stumbled upon Braskem, a material supplier new to additive manufacturing. They offered a carbon fiber reinforced polypropylene, which was lightweight, durable, and specifically designed for 3D printing applications. As an added bonus, they even utilize 100% recycled carbon fiber in their CF-PP formulation.
This was our first sign that we may be on to something special and that this undertaking had some legs. However, polypropylene is traditionally very difficult to 3D print and is historically known for its poor bed adhesion and excessive warping. Our expectations were low, but it was hard to ignore the unique balance of properties a carbon fiber polypropylene solution offered, so we continued on. Our next challenge was to find a machine fit for the task.
Finding the Right Machine
We had to decide what large format, high flow, pellet machine to use. Having limited options available on the market, we decided on the Titan Robotics Atlas large format 3D printer, which was listed on Braskem’s 3D website as a strategic partner. We ran some small test parts, using the recommended carbon fiber reinforced polypropylene pellets from Braskem, with some very promising results. Next, we increased the difficulty and decided to test print a larger flat sheet just to see if the material could live up to its claims of low warpage. Turns out Braskem appears to know what they are doing! By designing these pellets specifically for 3D printing instead of trying to retrofit a pellet that is typically used for injection molding, we were able to produce large flat sheets with minimal warpage, excellent layer adhesion and a “bed liner” like finish. With our printer selected and a handful of success test prints with the CF-PP, it was time to design the actual parts.
Designing for Large Format 3D
From our material trails on the Titan Robotics Atlas machine, we wanted to develop a design that functional, but also tested the limits of the material and the machine. Designing for 3D and especially large format 3D is always a bit different than traditional manufacturing, you need to have a keen understanding of the technology and the material so you can incorporate the proper print orientation, overhangs, seems, support structures, and correct geometries into your design that will help to optimize the overall print.
After many rounds of iterating we ended up with a unique design that we believe highlighted the capabilities of large format pellet 3D printing, while staying true to our mission. The end result, a set of jeep doors that kept the feeling of having the doors removed while also offering excellent functionality and style. We also incorporated a unique peg board design in the doors, these holes allowed us to design a handful of accessories that could quickly be attached and removed, such as a coat hook, a shovel clip — features that are sure to satisfy any outdoor enthusiast. But why stop there? We were having so much fun dreaming up applications for this material, we ended up convincing ourselves that we should whip up some custom fender flares as well.
Rock Star Results
The results of our efforts were more than impressive — they were outstanding. While our tests had given us a hint as to what the surface finish would look like, we had no idea these parts would come off the printer bed looking almost like molded plastic. It came down to the perfect pairing of material and machine. But the best part of this whole experiment? It took us just two days to complete. Two days(!), when we went into this expecting to spend four or five days per piece. How’s that for efficiency?! Ultimately, the screaming-fast turnaround time for production and low cost of pellet material made this a feasible product that could be produced in quantity. We consider this dragon slayed.