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

Why do 3D printers still go about their business at a glacial pace, when they have been available to consumers for over a decade?

The answer lies in the engineering and production challenges behind making 3D printing commercially viable. 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 Moving Fast

The first clue lies in a typical consumer 3D printer’s appearance itself. Searching Amazon for 3D printers yields results that look virtually indistinguishable from one another. That’s an unfortunate by-product of consumer 3D printers being based on the Prusa i3 design. There’s apparently no better approach to mass manufacturing cheap printers. Unfortunately, this pursuit of cost-efficiency comes at the cost of speed.

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

Full illuminated DIY LED strip lighting for 3D printer.

Your average consumer-grade 3D is cheap primarily because it is uncomplicated. This simplicity extends to their motion system as well. The X-axis, for example, comprises the print head moving along a length of V-slot aluminum extrusion. The Z-axis, in turn, moves the entire X-axis assembly up and down. That might seem like a lot of weight, but it isn’t a major concern because 3D printers move along the Z-axis infrequently and only a fraction of a millimeter at a time.

However, the Y-axis setup of such printers is definitely suboptimal. This poor axis is tasked with the Herculean task of moving the entire bed, which also happens to be the heaviest component in a 3D printer. To print fast, you ideally want the moving components to be as light as possible. It is already tricky to quickly move a print head weighing 150 grams, while maintaining micrometer precision.

Now, imagine doing the same with a 1.5kg bed instead. Not surprisingly, 3D printers employing the Prusa i3 design are colloquially named bed-slingers for this reason.

What Happens When You Print Fast Anyway?

We have figured out 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 putting tremendous stress on the stepper motors and causing them to overheat. Print quality is the first casualty in the fight between a weak motor and stubborn mass of a heavy bed. This manifests as ringing or ghosting caused by excessive vibration associated with printing fast.

In extreme cases, the 3D printer components can shake themselves loose over time. Although it is easy to re-tighten screws, printing fast on Prusa i3-style often leads to irreversible wear on the motion components. The worst hit are the cheap V-slot rollers used in the motion system of such printers. The plastic wheels running along V-shaped tracks on aluminum extrusions wear out significantly when subjected to fast printing speeds.

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

Delta Printers: Cheap and Fast, but Inaccurate

Delta 3D printers are designed from the ground up to be fast. Their light print head is quicker and more controllable due to its inherently lower momentum. Moreover, the Delta design uses fewer components than its bed-slinger counterpart, which makes it even cheaper to manufacture. Printers that are cheap as well as fast sound perfect, but then why don’t we see enough of them?

Delta 3D printer and major components.
Image Credit: Anycubic and Flsun.

Printers based on the Delta design compromise a lot in their pursuit of speed. Their compact and lightweight print heads make it impossible to implement a direct drive extruder. Learn more about this technology in our direct drive extruder guide. Meanwhile, this Bowden-only extruder restriction makes Delta printers incapable of handling flexible filaments, which hurts their versatility.

However, their biggest compromise comes in the form of reduced print quality, especially while printing large models that are spread out horizontally. Furthermore, the surface print quality achieved by a Delta isn’t comparable to bed-slingers. This is further exacerbated by the circular bed that limits build volume, and their general propensity to excel only at tall prints.

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

CoreXY Printers: Speed Comes at a Price

The quickest printers around are based on CoreXY kinematics, as explained in our beginner’s guide to Voron 3D printers. This is a sophisticated motion system where the bed is largely stationary, but the significantly lighter print head is moved at lightning quick speeds. 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 restricted to niche open-source projects aimed at 3D printing enthusiasts. That isn’t surprising considering how the average CoreXY 3D printer costs anywhere between $1000 and $2000 in parts alone.

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

Speed Is a Luxury 3D Printers Can’t Afford

To sum this up, fast 3D printing is an expensive affair. You can either have a cheap Delta printer that goes quick at the cost of quality and build volume, or you can spend a fortune on a CoreXY machine. Neither of these extremes sit well with consumers.

And that’s why virtually every consumer 3D printer is based on the Prusa i3 design. These printers might be slow, but they nevertheless strike a good balance between price, features, and performance. Speed is an unfortunate casualty of manufacturing 3D printers with mass market appeal.