Once you own a 3D Printer it can be easy to get carried away with all the cool things you can print. But is it always the best option? Let's compare machining (turning) four parts vs. 3D printing the same parts.
These spools are for a new product that removes Zeus FluoroPEELZ® heat shrink after reflowing catheters. They are 1" OD and feature a knurled grip and threaded holes. They are well suited to either machining or 3D printing. We'll consider these prototype components for this study.
Time to Make This is how long it took to machine or print the parts once the parts were designed. The machine parts beat the printed parts in this category by 30 minutes.
Material Cost The raw material cost. The printed parts pictured here were made with generic PLA and cost $0.58. But if your printer uses proprietary material, this can be as high as $3.84 for the set.
Additional Modeling Time These parts needed to be knurled so extra time was required to "cut" the knurls in SolidWorks. The machined part doesn't require the knurl to be modeled.
Labor Cost This is where the magic of leaving the printer unattended comes into play. This figure represents labor to model the extra features in CAD, and a quick printer setup. The machined part requires a machinist to spend the full 2 hours on the parts.
Total Cost The machined parts are over 3X more expensive when taking into account labor. This can vary, but 3D printing is a much more hands-off process and will usually be cheaper than machining for prototyping.
Robustness of Part Here is where the machined aluminum parts shine. They are of course much more robust. They are also a user touch-point and feel much better to the touch.
In this case, machining is the better option for these parts. The parts are stronger and feel better in the hands of the user. The decision to machine these parts was made with the user needs in mind. There is no single answer to the print vs. machine question. Each part must be evaluated on a case by case basis.