3d printers

Why are 3D printers so slow?

3D printing has become cheap and reliable over the years. Beginner-friendly materials such as PLA and PETG have made home-making more accessible than before. Unfortunately, the 3D printing process remains extremely slow, in many cases requiring several days of printing.

Why are 3D printers continuing at a glacial pace, despite having been available to consumers for over a decade?

The answer lies in the engineering and production challenges that underpin the commercial viability of 3D printing. Let’s take a look at these challenges and a promising technology that could make 3D printing faster for everyone.

Bed-slingers don’t like to move fast

The first clue is in the appearance of a typical consumer 3D printer. Searching for 3D printers on Amazon yields results that seem virtually indistinguishable from each other. It is an unfortunate byproduct of consumer 3D printers based on the Prusa i3 design. There’s apparently no better approach to mass-produce cheap printers. Unfortunately, this quest for profitability comes at the expense of speed.

Let’s take a look at the Prusa i3 motion system to understand why this is the case.

Fully illuminated DIY LED strip light for 3D printer.

Your average consumer 3D is cheap primarily because it’s simple. This simplicity also extends to their movement system. The X axis, for example, includes the printhead moving along a length of v-slot aluminum extrusion. The Z axis, in turn, moves the entire axis X from top to bottom. That may seem like a lot of weight, but it’s not a major issue because 3D printers rarely move along the Z axis and only a fraction of a millimeter at a time.

However, the Y-axis configuration of these printers is definitely sub-optimal. This poor axis is tasked with the herculean task of moving the entire bed, which also happens to be the heaviest component of a 3D printer. To print quickly, you ideally want the moving components to be as light as possible. It is already difficult to quickly move a print head weighing 150 grams, while maintaining micrometric precision.

Now imagine doing the same thing with a 1.5 kg bed instead. Unsurprisingly, 3D printers using the Prusa i3 design are colloquially called bed-slingers for this reason.

What happens when you print quickly anyway?

We understand why your average 3D printer is slow. But what if we were to disable firmware limits on print speed and acceleration to print fast anyway? The cost of moving too fast goes beyond straining the stepper motors and causing them to overheat. Print quality is the first casualty in the struggle between a weak motor and the stubborn mass of a heavy bed. This manifests as ringing or ghosting caused by excessive vibrations associated with fast printing.

In extreme cases, 3D printer components can become loose over time. Although it is easy to re-tighten the screws, printing the Prusa i3 style quickly often results in irreversible wear of the movement components. Most affected are the inexpensive v-slot rollers used in the motion system of these printers. The plastic wheels that run along the v-shaped tracks on the aluminum extrusions wear down considerably when subjected to fast print speeds.

The typical 3D printer based on the Prusa i3 design cannot print quickly with any degree of quality or long-term reliability. But what about printers based on different designs. There should be viable alternatives suitable for quick printing, right?

Delta printers: cheap and fast, but inaccurate

Delta 3D printers are designed from the ground up to be fast. Their lightweight printhead is faster and more controllable due to its inherently lower momentum. Additionally, the Delta design uses fewer components than its bed-slinger counterpart, making it even cheaper to manufacture. Cheap and fast printers sound great, but then why aren’t we seeing enough of them?

Delta 3D printer and main components.
Image credit: anycubic and flsun.

Printers based on the Delta design make a lot of compromises in their quest for speed. Their compact and lightweight printheads make the implementation of a direct-drive extruder impossible. Learn more about this technology in our direct drive extruder guide. Meanwhile, this Bowden-only extruder restriction makes Delta printers unable to handle flexible filaments, which hurts their versatility.

However, their biggest trade-off comes in the form of reduced print quality, especially when printing large, horizontally spread models. In addition, the surface impression quality obtained by a Delta is not comparable to that of bed-slingers. This is further exacerbated by the circular bed which limits build volume and their general propensity to only excel at tall prints.

These limitations are severe enough that the consumer 3D printing industry has relegated Delta printers to a niche despite their impressive speed and cost effectiveness.

CoreXY Printers: Speed ​​Comes at a Price

The fastest printers on the market are based on CoreXY kinematics, as explained in our beginner’s guide to Voron 3D printers. This is a sophisticated motion system in which the bed is largely stationary, but the significantly lighter printhead is moved at lightning speed. Unlike Delta printers, the CoreXY design maintains quality while allowing the use of direct-drive extruders.

The Voron 0 3D printer.
Image Credit: Paul Nokel/Voron design

The only problem is that the extreme complexity and high costs involved make these printers unviable for consumer 3D printing. As such, CoreXY printers remain limited to niche open source projects aimed at 3D printing enthusiasts. This is not surprising considering that the average CoreXY 3D printer costs between $1,000 and $2,000 in parts alone.

Consumer 3D printer manufacturers still haven’t figured out how to make this technology affordable and accessible enough for mainstream users.

Speed ​​is a luxury 3D printers can’t afford

To sum up, fast 3D printing is expensive business. You can either have a cheap Delta printer that goes fast at the expense of build quality and volume, or spend a fortune on a CoreXY machine. None of these extremes appeal to consumers.

And that’s why virtually all mainstream 3D printers are based on the Prusa i3 design. These printers can be slow, but they still offer a good balance of price, features, and performance. Speed ​​is an unfortunate victim of making 3D printers appealing to the mass market.


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