How do suppliers calculate pricing for 3D prints?

Jul 21, 2016 | By James Smith

I’ve looked at quotes for 3D printing from a few suppliers and there is a wide price difference between them. Why is that?

This is a question I’m frequently asked by people who are looking at getting something 3D printed. Big differences in price between suppliers can be baffling, especially when the supplier who was cheapest for your last part inexplicably becomes the most expensive option for your next part.

As a co-founder of a 3D printing service that works with suppliers all over the world to provide 3D printing services using all major technologies, I’ve had more insight than most people into how commercial 3D printing is priced by different companies. The market is still fragmented, and it’s hard for customers to compare options between different technologies and suppliers, a problem we’ve solved by working with suppliers to create a single platform for comparing pricing across the industry.

I’ve written this article to share some of the insights I’ve gained on 3D printing pricing with you in order to help you understand what factors influence the price you see when you get a quote for 3D printing. We’ll cover the major factors that drive all production process, and dive deeper in the pricing factors for each of the major 3DP technologies.

The most common factors in price

First, there is no industry standard for calculating price. Each industrial 3D print supplier has their own way of calculating a price, and different suppliers operating the same machines may still use very different formulas for pricing. Some 3D print suppliers rely on recommended pricing models provided by their hardware manufacturers. Others take into account different factors that make sense for their business.

It’s important to distinguish price from cost. Cost is what a supplier has to pay for the materials, equipment, and people needed to 3D print something for you at their facility, and price is what they charge you for it. Generally, price IS related to cost in some way, with costs calculated and then profit margin applied afterwards.

The major cost drivers for suppliers are generally the following:

3D print time. The more time a 3D print takes, the more depreciation and maintenance.
The cost of labor. There is some time required for an operator to get a machine started and to remove parts from the machine after printing, and any post-printing finishing also takes extra time.
The cost of the raw materials and other consumables. These are what the part is made of (filament, powdered plastic/nylon/metal, resin, argon gas, etc.).

Each of these cost drivers has associated pricing factors. These factors create a relationship between the characteristics of the part and the overall cost. Some of the most common price factors are shown in the table below, mapped to the relevant cost drivers.

Cost Driver	Common Price Factors
3D print time	Part bounding box volume (how much of the printer does the part use?) Height of part (how many layers will be needed?)
Labour	Setup fee (how much time is needed to set up the print?) Finishing fee (how much time is needed to do post-print surface finishing?)
Raw materials	Part volume (how much material goes into the part?) Support volume (how much material goes into the supports?)

Now that we’ve covered the basics, let’s get into the details on price inputs organized by the different 3D printing technologies.

Price inputs for the different 3D printing technologies

Fused Deposition Modeling (FDM)

An ABS scale model 3D printed using FDM (Image credit: James Smith)

FDM extrudes melted thermoplastics out of a hot nozzle and builds up shapes from that extrusion layer by layer.

Pricing for FDM is usually fairly simple, and expressed as a price per cubic centimeter or cubic inch of material. This includes the part’s volume and the support material volume

There is a time factor included in the cost of the 3D print; however, this is most often included in the price per cubic centimeter/inch.

Even though this is the most common way to calculate pricing for FDM, some vendors have used part volume alone.

Depending on the 3D print supplier you choose and the 3D printer they are using, support material could be the same material as the 3D print that is broken away, or it is an entirely different material that can be dissolved away leaving just the printed part.

Another factor that is unique to this type of printing is whether or not the part is printed solid. If the print is solid, more material is used for the print, thereby increasing the cost.

Most of the commercial printers in this class are capable of printing accurate layers as fine as .254mm (0.01”) in thickness. If you want thinner layers, and the printer / material combination supports it, then the cost will be higher due to a longer machine time required to produce your 3D printed part.

Exotic materials, such as Ultem or PPSF, typically are higher priced per cubic centimeter/inch than traditional thermoplastics (ABS and PC) and may not supported by the majority of industrial 3D printing machines.

Selective Laser Sintering (SLS)

A nylon assembly 3D printed using SLS (Image credit: James Smith)

SLS 3D printing builds parts up by first laying down a thin layer of fine powdered material on a build plate, such as nylon plastic, then precisely fusing (sintering) powder particles together using a high-powered laser. After each layer is built, the build plate moves down slightly and the process is repeated until the part build is complete.

The primary advantage of using this method for 3D printing is that there is no need for support material, since the non-sintered nylon powder acts as its own support for the print.

The two most common methods for calculating SLS prices are either based on the 3D printed part volume (the amount of sintered nylon) or by the bounding box volume (the total space the part takes up in the machine).

Depending on your part geometry and part / bounding box density, one price model may be more cost effective than the other. It’s good to compare which 3D print supplier prices are the most economical side by side. If you have a small, dense part, it may be cheaper at one supplier, whereas a big part with lots of empty spaces inside it will be cheaper at another supplier.

Stereolithography (SLA) and Polyjet

A part 3D printed using SLA, By Binarysequence (Own work) [CC BY-SA 4.0 (http://creativecommons.org/licenses/by-sa/4.0)], via Wikimedia Commons

SLA technology produces parts layer by layer using photopolymerization, a process where UV light causes chains of molecules to link together. The part is built down into a photopolymer resin bath. When the print is complete, the bath is drained, revealing the completed 3D printed part.

PolyJet printer systems spray and cure photopolymer materials onto a build tray in ultra-thin layers until the part is completed, similar to how an inkjet printer works. Like SLA, each PolyJet layer is cured with UV light after it is jetted. The gel-like support material, which is designed to support complicated geometries, is removed by hand and water jetting.

These 3D printing technologies are for printing models that require a very high degree of accuracy, or, in PolyJet’s case, multiple materials in a single part.

Pricing variables we often see using SLA and PolyJet technologies include part volume, support volume, bounding box volume, and machine time. Often, the cost of the print will be optimized by finding a part orientation that balances minimum height and minimum support to achieve minimum overall price. In the case of PolyJet, if multiple materials are required, then the specifics of which materials are needed and how much of each are required will be a factor in calculating the price.

These technologies tend to be a bit pricier than other forms of plastic 3D printing, as the highly accurate 3D prints take more time to produce and the photopolymer plastic materials are more expensive.

If you require highly accurate 3D prints, however, SLA and PolyJet are what you are looking for.

Direct Metal Laser Sintering (DMLS)

A golf club head 3D printed using DMLS (Image credit: James Smith)

DMLS technology is similar to FDM in that parts printed using this method require support for overhangs. However, DMLS is also similar to SLS in that the fine metal powder is evenly distributed across the build plate in thin layers before a high-powered laser precisely sinters the metal powder together. The process is repeated over and over until the 3D printed part is complete.

In many cases, one machine is capable of printing different metals, which may be priced differently.

Machine time is often factored in to the total cost by measuring the part’s orientation on the Z axis (i.e. the height). Since the machine has to spend more time laying down more layers of powder for a taller part, it takes the machine longer to print a part if it is “standing up” vs “laying down”. If you want to minimize the price of 3D printed metal parts, orient the parts so that open faces are oriented up (reduces required support) and that the Z axis is as small as possible (i.e. lay the part as flat as possible).

The primary methods used for determining a DMLS 3D printed part’s price are part volume, support volume, and machine time. Less commonly, we also have seen instances where price is calculated based on a volume defined by optimum orientation, X and Y and a maximum Z. This relies on a 100% print volume utilization assumption.

Because of these differences, you are likely to see wide variances in metal 3D printing pricing.

With DMLS 3D printing, you will likely also see higher minimum pricing in place – that means you’ll end up paying a pre-determined minimum fee for parts below a certain size, regardless of how small they are. Also, the setup and part finishing fees are higher for metal parts, since the finishing work needed for metal parts is more time consuming than with the plastics.

It is also worth noting that you may require additional post processing to get the surface quality you want, which can add to the cost and price. 3D printed metal parts made from DMLS technology can be welded and can be polished. Be sure to specify what type of finish you need for your metal 3D printed part up front since this can have a noticeable impact on the price.

Now we better understand what goes into calculating 3D printing prices

I hope this article gives you a better understanding of the various parameters that affect how 3D print prices are calculated. We think the best way to navigate these price variations is to compare prices on one screen. If you'd like to learn more, Made for Me's extensive 3D print supplier network lets you compare prices and production times from a wide range of industrial 3D printers.

*James Smith is a Co-Founder and the COO at Made for Me, a global platform for professional 3D printing services.

Posted in 3D Printing Service

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