Comparing the 3D Printing Methods

Comparing the 3D Printing Methods

When looking at 3D Printing, there are several methods that a company can consider, depending on the needs of a company. For this analysis, three different methods will be considered: Fused Deposition Modeling (FDM), Stereolithography (SLA), and Selective Laser Sintering (SLA).

 

Fused Deposit Modeling/Filament Fabrication (FDM/FFF)

FDM is a kind of 3D printing technology that melts and extrudes thermoplastic filaments based upon a pre-determined path. It does this by extruding material layer by layer. This technology is the most accessible to the public, smaller companies, and for companies looking to do simple prototyping or seek proof-of-concept modeling. Due to its low barrier to entry, this technology provides parts that are lowest in resolution and accuracy. This method is clean, easy to use, and very office friendly. But FDM suffers from warping tendencies when printing a large flat area, protruding features, sharp corners, and certain materials (ABS).

Price and Labor

The price of an FDM printer ranges anywhere between €250 to upwards of €12,000. For a low-end, consumer personal printer the cost is approximately €250, but is limited to the amount of prints it can make. This version is ideal for at-home 3D printing. If manufacturing is the goal, then an industrial printer is needed – these run upwards of €12,000.

Another factor to consider when running an FDM printer is labor and training needed to use this printer effectively. Luckily for everyone, this printer requires minor training on build setup and machine operation/finishing. Additionally, it requires a laborer to remove the product out of its manual support – however, this can be automated with a soluble system.

Source: 3DNatives

Stereolithography (SLA)

SLA is one of the most common forms of 3D printing. This method works by using a high-powered laser to harden liquid resin. Resin is released from a reservoir inside the machine and is added layer by layer to make a 3D model. A good benefit for this technology would be its highly versatile material selection. SLA provides the highest resolution and accuracy. Those looking to keep tolerances tight and have fine details to their 3D model should consider this option. This option is good for those looking to create models for functional prototyping, patterns, molds, and tooling.

Price and Labor

Overall, an SLA printer provides much better results than an FDM printer, but it comes with a much higher price tag – where a machine costs about 10 times a typical FDM 3D printer. SLA printers start with mini versions for personal use at about €200. However, professional desktop printers start at €2,800. These printers have a higher accuracy and bigger than personal printers. They can fill the role of industrial production from a machine the size of a desktop.

Still, the most accurate, largest, and flexible machines in the market are industrial printers. These printers are upwards of €65,000 – with some versions costing over €100,000.

Much like an FDM printer, this machine is very simple to use and setup. However, an SLA printer is much easier to maintain and much easier to obtain a smooth and polished finish to a product. Some could characterize this printer as a plug and play printer. In terms of labor, since this product is formed from a pool of resin, the print needs to be washed and cured – both of which can be automated, especially in an industrial setting. Estimates place the labor needed for curing to be more than 20 minutes, washing 5-20 minutes, and drying at 30 minutes.

Source: 3DNatives

Selective Laser Sintering (SLS)

SLS printing is a technology that uses a laser to sinter together powdered plastic material into a solid structure. This method has been a popular choice due to its low cost per part, high productivity, and for not having support structure. The products provided by SLS can be compared to injection molded parts. This method is best used for companies looking to create products for functional prototyping and customize manufactured parts.

Price and Labor

The price for an SLS printer can be extensively expensive. SLS machines are more optimized for the industrial setting. A benchtop SLS printer, a miniaturized version of an industrial printer, can cost upwards of €8,000. These printers are small enough to sit atop a shop/garage workbench. Industrial printer at €80,000 or more.

However, one area where this printer can be optimized much more than the former two options would be its material reusability. The powder that is not ultimately fused into the mold can be removed and reused for other prints.

Since this printer is a more industrial printer, it requires more training on build setup, maintenance, machine operation, and finishing. However, this is offset by the simple cleaning and removal process of a print. All a laborer must do is collect the unfused powder, remove the print, and restart the device for the next job. This process can also be automated.

Costs of Defects – Effect of Cheap Material

Probably one of the most important factors to consider when choosing to use a 3D printer is the time it takes to obtain a full print and wasted material. The use of poor-quality material, where filler materials and poor spool winds are more likely, can cause a print to fail before completion. A failed print can cost time and material. This would far outweigh the tempting short-term benefits a company can obtain by choosing to opt in for a cheap material.

3DFuel has put together two different scenarios where costs can be potentially different. Scenario 1 presents a normal print completion using a cheap filament. This presents a large overall cost savings in terms of materials and per print price.

However, given a cheap material is more likely to fail a print, they have presented a second scenario. This time, Scenario 2 is given a first print failure at 50% completion, only for it to be rerun and successfully made. The hours sunk into the part and the amount of material multiply by 1.5. However, this will also incur costs in terms labor needed for un-jamming and component repairs.

3D Printing and Injection Molding – Insourcing and Outsourcing

Finally, when a company looks toward insourcing or outsourcing different manufacturing methods, some factors need to be considered. Insourcing, for the most part, has a large barrier to entry due to expensive machinery and establishment of the labor needed. However, insourcing comes with the benefit of economies of scale. As printers and injection molders become more frequently used, the more it produces, the cheaper it is to create products. Listed below are some key differences between insourcing and outsourcing.

3D Printing

Insourcing

  • Benefits
    • Economies of scale makes this process more efficient.
    • Return on investment of high-cost machines increases as more products are made.
    • Fastest lead time as products are produced on a as needed basis.
  • Variable Cost (VC)
    • Labor for appropriate finishing: Washing, Drying, and Curing
    • Technicians needed for appropriate 3D printing.
    • Materials for printing.
    • High-cost machinery needed for printing.

Injection Molding

Insourcing

  • Benefits
    • Economies of scale makes this process more efficient.
    • Overall, injection molding pellets are slightly cheaper than 3D printing material.
    • Lower failure rate than 3D printing, faster production once mold is created.
  • Variable Cost (VC)
    • Labor needed for creation of the mold and running of the injection mold machine.
    • Technicians needed for setting appropriate settings such as temperature, flow rate, etc.
    • High cost of injection molding machines.
    • Pellet materials needed for injection molding.

Outsourcing

  • Benefits
    • Lowest barrier to entry as a high-cost machine is not needed.
    • Fast lead time, when compared to injection molding.
  • Fixed Cost (FC)
    • Parts are charged on a per product rate.
    • As more products are produced, rates can be slightly reduced.

Outsourcing

  • Benefits
    • Lowest chance of failure and most tailored to a company’s needs.
    • Low barrier to entry if seeking a fast-prototyping mold.
  • Fixed Cost (FC)
    • Parts are charged on a per product rate, but cheaper once a mold is created.
    • Creation of the mold is priced into the cost; this is the most expensive part.

Conclusion:

When looking into 3D printing, a company has different options to consider. To summarize, a company must investigate what kinds of print properties they are looking for. If a low accuracy and detailed model is needed, then a cheap alternative such as FDM 3D printing should be sought out. SLA and SLS are a much more accurate methods of printing but suffer from post processing needs and higher costs. Another factor to consider would be the effect of cheaper materials and the risk a company takes if it were to cause prints to fail.

Outsourcing and Insourcing can also prove to be large cost contributors to both methods of manufacture. A company can avoid either fixed or variable costs by weighing the benefits that each method can provide. It is ultimately up to the capability of a company to determine if high barriers to entry, economies of scale, or risk play a large factor in production of their products.


3D Printing vs. Injection Molding

3D Printing vs. Injection Molding

One of the biggest developing technologies emerging in the modern era is 3D printing, an additive form of manufacturing that seeks to alter the way companies go about producing new products and possibly even manufacturing itself. As like any other new technology, as it develops, the overall usage price drops to a point of commercial viability. Today, 3D printing has found itself a market where it can be used appropriately to facilitate prototyping and even reduce lead times. It has the potential to accelerate production and improve productivity. However, the question remains as to whether this technology can replace current conventional manufacturing methods. To explore this idea, 3D printing will be compared to a conventional manufacturing method, injection molding.

Injection Molding and 3D Printing in Manufacturing

Injection Molding plays a big role in producing parts in large volumes and moving a product into mass production. This process has been a staple in the industry for its ability to reduce waste when compared to CNC machining – a process where a block of metal is cut away to create a product. When running an injection molding process, the only waste obtained would be from the runner, sprue, and gates. If a company uses a slightly more expensive thermoplastic material, then this waste can be remelted and reused for other injection molds. Overall, by reusing and reducing waste, this can serve to reduce overall material costs.

However, it must be understood that the mold presents itself as a high entry cost to this manufacturing method. Creating the mold can range anywhere in between $1,000 to an excess of $80,000, depending on the complexity of the model. Before any kind of injection molding can be done, the mold must be manufactured. This alone can lead to long lead times and could delay company productivity until the model can be made. However, this process becomes more economically efficient as production is increased. As economies of scale take its effect, this process gradually reduces the cost per part manufactured. This makes this manufacturing methods ideal for large production companies and for those can afford to pay the high barrier to entry.

The benefits from economies of scale can be amplified for more complex products. With injection molding, a more complex part is coupled with a more complex mold, this of course, causes the cost to rise. Meanwhile, 3D printing has no added costs associated with increasing complexity but lacks the benefit of cost reduction per part as manufacturing increases. As we can see in the infographic below, injection molding proves to be more cost effective in large scale operations. It can also be noticed where the cross over point is for the two processes, showing at what cost per part and what production level the two processes are equal. It can also be concluded that 3D printing is more cost efficient at lower levels of production. This case uses polylactic acid (PLA) as an analysis. The case shown below comes from Sculpteo – a brand of BASF company:

Rex Plastics, an American plastic manufacturer has put together a graph detailing the cost estimates for each mold. Rapid prototyping tooling is a fast and cost-efficient way to carry out low-volume injection molding for several types of plastic parts. Insert tooling combines metal and plastics, or multiple combinations of materials and components into a single mold. This improves wear resistance, tensile strength, conductivity, and allows for tighter tolerances. High production tooling allows for molds to be specifically designed for high production. This means tighter tolerances, endurance, high automated wear maintenance provisions, and process control capabilities. Cost estimates for the three options are listed below.

For smaller companies, 3D printing can serve as a good alternative. By either outsourcing or purchasing your own 3D printing machine, the product needed can be printed in a matter of a day or two and can quickly be rushed into production or to wherever needed in the logistics train. Additionally, this process is known for its very low waste turnover with each product manufactured. 3D printing is an accurate form of manufacturing a product, however it does run with a higher risk of failure. Certain estimates place this at around 20%. Due to the high rate of failure, there is a risk of wasting material and time.

A Cost Analysis: Car Frame
Based upon market prices for common materials used for 3D printing and injection molding, we can obtain a preliminary estimate for the cost of materials. Listed below is the cost for each material in terms of euros per metric ton.

Using a cost calculator from Xometry, a company focused on the production of products, we can determine a general estimate for how much a part would cost for both injection molding and 3D printing. For this analysis, a car fender with a 1643.32 cm3 volume will be analyzed with three separate manufacturing techniques – HP Multi Jet Fusion, SLS 3D printing, and injection molding.

SLS printing is a technique that uses a laser as the power source to sinter powdered material such as Nylon or Polycarbonate, often resulting in a rougher but stronger part. HP Multi Jet Fusion is relatively newer way to 3D Print. For this process, printing is done layer by layer as a fusing agent is added with each pass. For both 3D printing studies below, Nylon 12 30% Glass Filled is used as the base material, resulting in 3.22 kg of material used. The results are listed below.

Conclusion

Overall, there are more than just cost factors to consider when deciding to use either 3D printing or injection molding. These factors include time, finish, accuracy, and quantity. It is up to the company to determine what methodology is best in producing what they need. However, the question of whether a company can substitute either forms of manufacturing is clear. 3D printing can serve as a good compliment rather than a substitution. It can be well-used for rapid prototyping or low-scale production levels. It can serve as a proper bridge between the two and ultimately optimize the production cycle of a company.