Hands on with resin 3D printers: We put the Elegoo Mars, Mars Pro, and Zortrax Inspire to the test

We test three resin printers, including one that's almost 10 times the price of the other two.
Written by David Gewirtz, Senior Contributing Editor

We've been testing three resin 3D printers: The Elegoo Mars, the Elegoo Mars Pro, and the Zortrax Inkspire.

Disclosure: ZDNet may earn an affiliate commission from some of the products featured on this page. ZDNet and the author were not compensated for this independent review.

The Elegoo Mars is about $249 on Amazon (the price fluctuates a bit with sales). The Mars Pro is fifty bucks more. And the Inkspire is almost ten times the price -- at almost $2,000.

When we began testing each of these three printers, we wanted to find out what they can do and how well they do it. We set out to answer the burning question of the hour: is the Inkspire worth 10 times the price of the other two?

Each of these machines is an SLA (or Stereo Lithography) printer. Instead of solid plastic filament, they use a liquid resin.

In the accompanying video, you'll see me wearing a lab coat. Until the resin is cured with UV light, it's toxic as heck. I don't want any resin on my T-shirt or pants, even a tiny droplet, especially since I have a little dog who likes to climb up on Daddy's lap.

It's also why you'll see me standing in front of my garage door instead of in the Fab Lab with the FDM filament printers. The resin and the 99% isopropyl alcohol put out some pretty noxious fumes. Near the garage door is the part of my shop where I work with paints and chemicals, so I can open the garage door to vacate the gases quickly and easily.

The Elegoo Mars and Mars Pro

The Mars was introduced a few years ago to pretty much rave reviews, especially for the price. The Mars Pro moves the USB port to the front of the machine and adds a rubber gasket inside to help manage the fumes.

Unfortunately, I found the gasket's fit and finish isn't perfect, although it does do the job. The company tells us that the printer's UV light's power and uniformity have improved. Since this is what actually makes the plastic object, that's worth considering.

In addition to the gasket, the Mars Pro also adds a new filter which should help to better contain the noxious fumes.

The company added a new stepper motor and rail system to reduce the noise and increase the print speed. Finally, a firmware upgrade is supposed to provide anti-aliasing, which should make for smoother prints.

The Zortrax Inkspire

Jumping from about $300 to $10 short of $2,000, we come to the Inkspire. Unlike the two Mars devices, the Inkspire has both Ethernet and Wi-Fi networking capabilities.

Zortrax's Z-SUITE software allows remote management of the printer, which could prove valuable in professional environments. While a Raspberry Pi and Octoprint can do the same thing for filament printers for about fifty bucks, there are currently no plans for Octoprint to support resin printers. Therefore, remote printer management for the Inkspire may well be a substantial advantage worth the added cost, especially for print farms.

Subjectively, the Inkspire is heavier and seems more sturdy than the two Mars printers, but both are shockingly well built for a sub-$300 printer.

And here's where things get really confusing. All three machines have touchscreen interfaces but their performance specs are nearly identical -- including the one that's much more expensive than the other two.

While the Mars and Mars Pro have a 120 x 68 x 155mm total print area, the Inkspire's isn't much larger. It's 132 x 74 x 174mm, barely ten percent larger.

The X/Y resolution of all three printers is about 21 pixels per millimeter, or a resolution of about 47 microns. Zortrax says its minimal layer height is 25 microns, where Elegoo says the Mars can attain a finer layer height of 10+ microns (the plus is the question, of course).

This is why performance testing is so important. You can see me go hands-on (gloves, respirator, goggles on, too) as I put these resin printers through their paces. The resin is toxic, so it was a messy experience. Go ahead and watch the video to see me at my most dapper best.

Test results

After about two weeks working on the project, things didn't go the way I expected. The $250 Elegoo Mars and the $300 Mars Pro performed perfectly. On the other hand, the nearly $2,000 Zortrax Inkspire failed miserably.

I wasn't able to print a single model on the Inkspire successfully. For whatever reason, the Inkspire didn't come with a sample print, so I don't even have a factory-tuned model to print and show you.

Over a few days, I put 20 hours into the Inkspire, with three failed prints each taking about five hours, and another five or so hours fiddling with it and cleaning out the resin and residue from the failed prints. I tried a basic Benchy. Then I tried the foot soldier model I used to test the Mars printers. When that failed using Zortrax' Z-suite, I tried it using the Inkspire profile from Chitubox, the popular slicer that's used with the Mars printers. Nothing worked.

Look, it's entirely possible that what we're seeing here is user error rather than product failure. This is my first time printing with resin, and while I followed Zortrax's directions exactly, it could be I'm missing something. I have reached out to the company, but unfortunately, they haven't responded in time for my deadline.

If they do get back to me and can show me the error of my ways, I'll do another video summarizing any new results.

In the meantime, let's look at the two out-of-this-world Mars printers.

Print quality for tiny objects is impressive. To the naked eye, the prints that come out of both Mars devices seem more like castings than typical 3D prints with the layer lines endemic to filament printers.

In the video, you can see the rooks that serve as the sample prints for the Mars printers. They're quite impressive, although there does seem to be a small blemish at the bottom of the Mars Pro rook. This could simply be an artifact of that individual print run.

Zooming in with a macro lens, you can see the detail both Mars printers can produce. You can see that the double-helix and staircase are rendered beautifully inside the rooks.

Zooming in even more, it's only once you look at the objects under the microscope that you begin to see any artifacts. That's pretty impressive.

The detail difference between filament and resin printers becomes even more apparent in a miniature foot soldier, designed for support-free SLA printing by Thingiverse contributor BriteMinis.

In the video, I show the model printed with filament in 0.2mm layer height on the CR-10. You can also see the same model in a 0.1mm layer height printed using the high-res SL tool head on the LulzBot Mini 2. Unfortunately, I ran out of the gray filament and the bright green has less contrast and is harder to photograph. Even so, you can see layer lines under the shield.

By contrast, you can see the clean output from both the Mars and Mars Pro. From these, you can begin to see why SLA resin printers have such an appeal to miniature gamers, model railroaders, doll makers, and jewelry designers.

Let's put the soldier under the microscope as well. In the video, you can see the big, thick 0.2mm filament layers in the hand and the soldier's face. Again, it was a bit challenging to photograph the green filament, but you can still see the layer lines.

Now, though, let's switch to the Mars printers. This is the hand and face on the Mars printer, and the video shows the detail more than just the artifacts of the print process. While the hand isn't quite as nice on the Mars Pro, the facial detail is so complete you can even see the cheekbones.

Remember, this is a very small model. Lincoln's head on a penny is just about the same size as the soldier's head and the detail is similar.

Finally, I decided to print a slightly bigger model, in this case, the Enterprise NX-01 from Star Trek by Thingiverse user KonP69. This print showcases both the wonder and challenge of resin printing. You can see the front of the Enterprise on the accompanying video. It looks pretty amazing for such a small print.

Even zoomed in, the model is quite detailed. You only begin to see artifacting once you look at the model under the microscope.

But that's on the top. I used the auto-support tool from Chitubox to create a platform that would allow this model to print. On the side of the model with supports, the video shows the pockmarks and blemishes left by the supports. That said, there are resin printer users who hand-place each support pylon and get better results, but I'm not there yet.

Final thoughts

So there you go. After wallowing in toxic goo for a few weeks now, I have to say that resin printing is not a favorite activity for me. I like building brackets and fixtures, which is the domain of FDM filament printers. That said, if I played games with miniatures, made models, or designed jewelry, the Mars printers would be an ideal choice.

For $250 to $300, the quality of the Elegoo Mars prints is excellent. So is the build quality. These two printers are definite price/performance/value champions compared to nearly every other 3D printer I've looked at.

As for whether you should get the Mars or the Mars Pro, I'd recommend you get the Mars Pro if you can handle the extra fifty bucks. It's essentially the second-generation printer and is worth the small added cost.

That said, I do have one complaint about both Mars printers. They don't come with any resin, not even a tiny amount to print a rook or two. Once the printers came in, I had to separately order and wait for the resin to arrive. I know they're trying to keep costs down, but not being able to print even one model right out of the box is disappointing.

As for the nearly $2,000 Inkspire, I can't recommend it at this point. It supports a wide range of resins, including specialty resins like those for dentistry. It will probably find a welcome home in some industrial applications, but it was a non-starter in my testing. I did reach out to the company and If Zortrax responds with guidance that changes my results, I'll try to get back to you with an update.

On a final note, Zortrax did provide an ultrasonic cleaner that came in handy cleaning the models printed on the Mars machines. The cleaner worked just fine and I can definitely recommend it. Of course, at $299, the Zortrax ultrasonic cleaner is the price of the entire Mars Pro. There are also considerably less expensive and equally functional ultrasonic cleaners available on Amazon.

So there you go. Getting started with resin printing can be relatively inexpensive with these Elegoo printers. Let me know in the comments below if you think this is something you're going to explore.

Have you done SLA printing before? If you're a filament 3D print maker, do you think you might expand your portfolio with a resin printer? I'd especially like to hear from miniature gamers, model makers, and jewelry designers? Do you agree with my assessment that a resin printer is ideal for your work?

I'd also like to hear from anyone using resin printers for other kinds of projects? What else is a resin printer ideal for? Share your thoughts with everyone in the comments below.

You can follow my day-to-day project updates on social media. Be sure to follow me on Twitter at @DavidGewirtz, on Facebook at Facebook.com/DavidGewirtz, on Instagram at Instagram.com/DavidGewirtz, and on YouTube at YouTube.com/DavidGewirtzTV.

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