Filament-based 3D printers spent a long time at the developmental forefront for hobbyists, but resin-based printers have absolutely done a lot of catching up, and so have the resins they use. It used to be broadly true that resin prints looked great but were brittle, but that’s really not the case anymore.
A bigger variety of resins and properties are available to hobbyists than ever before, so if that’s what’s been keeping you away, it’s maybe time for another look. There are tough resins, there are stiff resins, there are heat-resistant resins, and more. Some make casting easy, and some are even flexible. If your part or application needs a particular property, there is probably a resin for it out there.
The quality of consumer-grade 3D printing has gone way up in recent years. Resin printers, in particular, can produce amazing results and they get less expensive every day. [Squidmar] took a miniature design and printed it (or had it printed) on some cheap resin printers and a 65,000 Euro DWS029. How much difference could there be? You can see for yourself in the video below.
We were surprised at the specs for the more expensive machine. It does use a solid-state laser, but for that cost, the build volume is relatively small — around 15 x 15 x 10 cm. There were actually five prints created on four printers. Three were on what we think of as normal printers, one was on the 65,000 Euro machine, and the fifth print was on a 10,000 Euro printer that didn’t look much different from the less expensive ones.
Of course, there is more to the process than just the printer. The resin you use also impacts the final object. The printers tested included a Phrozen 4K Mini, a Phrozen 8K Mini, a Solos Pro, and the DWS 029D. The exact resins or materials used was hard to tell in each case, so that may have something to do with the comparisons, too.
Do you get what you pay for? Hard to say. The 8K and Solos were neck-and-neck with some features better on one printer and some better on the other. The DWS029D did perform better, but was it really worth the increase in price? Guess it depends on your sensitivity. The 8K printer did a very credible job for a fraction of the cost. Of course, some of that could have been a result of the materials used, too, but it does seem likely that a very expensive dental printer ought to do better than a hobby-grade machine. But it doesn’t seem to do much better.
The DWS printer uses a laser, while most hobby printers use UV light with an LCD mask. We’ve seen low-end resin printers on closeout for around $100 and you can get something pretty nice in the $200 neighborhood. In between these two extremes are printers that use Digital Light Processing (DLP).
Join us on Wednesday, October 13 at noon Pacific for the Resin Printing Hack Chat with Andrew Sink!
At its heart, 3D printing is such a simple idea that it’s a wonder nobody thought of it sooner. Granted, fused deposition modeling does go back to the 80s, and the relatively recent explosion in cheap, mass-market FDM printers has more to do with cheap components than anything else. But really, at the end of the day, commodity 3D printers are really not much more than glorified hot-glue guns, and while they’re still a foundational technology of the maker movement, they’ve gotten a bit dull.
So it’s natural that we in this community would look for other ways to push the 3D printing envelope, and stereolithography has become the new hotness. And with good reason — messy though it may be, the ability to gradually pull a model from a tank of goo by selective photopolymerization looks magical, and the fine level of detail resin printers are capable of is just as enchanting. So too are the prices of resin printers, which are quickly becoming competitive with commodity FDM printers.
If there’s a resin printer in your future, then you’ll want to swing by the Hack Chat when Andrew Sink visits us. Andrew has been doing a lot of 3D printing stuff in general, and resin printing in particular, over on his YouTube channel lately. We’ve featured a couple of his tricks and hacks for getting the most from a resin printer, and he’ll be sharing some of what he has learned lately. Join us as we discuss the ins and outs of resin printing, what’s involved in taking the dive, and the pros and cons of SLA versus FDM.
To the extent that we think of 3D printers as production machines, we tend to imagine huge banks of FDM machines slowly but surely cranking out parts. These printer farms are a sensible way to turn a slow process into a high-volume operation, but it turns out there’s a way to do the same thing with only one printer — as long as you think small.
This one comes to us by way of [Andrew Sink], who recently showed us a neat trick for adding a dash of color to resin printed parts. As with that tip, this one centers around his Elegoo resin printer, which is capable of intricately detailed prints but like any additive process, takes quite a bit of time to finish a print. Luckily, though, the printer uses the MSLA, or masked stereolithography, process, which exposes the entire resin tank to ultraviolet light in one exposure. That means that, unlike FDM printers, it takes no more time to print a dozen models than it does to print one. The upshot of this is that however many models can fit on the MSLA print platform can be printed in the same amount of time it takes to print the part with the most layers. In [Andrew]’s case, 22 identical figurine models were printed in the same three hours it took to print just one copy.
It seems obvious, but sometimes the simplest tips are the best. And the next step is obvious, especially as MSLA printer prices fall: a resin printer farm, with each printer working on dozens of small parts at a time. Such a setup might rival injection molding in terms of throughput, and would likely be far cheaper as far as tooling goes. Continue reading “Making The Most Of Your Resin Printer Investment”→
The fascination of watching a 3D printer go through its paces does tend to wear off after you spent a few hours doing it, in which case those cool time-lapse videos come in handy. Trouble is they tend to look choppy and unpleasant unless the exposures are synchronized to the motion of the gantry. That’s easy enough to do on FDM printers, but resin printers are another thing altogether.
Or are they? [Alex] found a way to make gorgeous time-lapse videos of resin printers that have to be seen to be believed. The advantage of his method is that it’ll work with any camera and requires no hardware other than a little LED throwie attached to the build platform of the printer. The LED acts as a fiducial that OpenCV can easily find in each frame, one that indicates the Z-axis position of the stage when the photo was taken. A Python program then sorts the frames, so it looks like the resin print is being pulled out of the vat in one smooth pull.
To smooth things out further, [Alex] also used frame interpolation to fill in the gaps where the build platform appears to jump between frames using real-time intermediate flow estimation, or RIFE. The details of that technique alone were worth the price of admission, and the results are spectacular. Alex kindly provides his code if you want to give this a whack; it’s almost worth buying a resin printer just to try.
Over the last couple of years, we’ve seen massive price reductions on consumer 3D printers based on masked stereolithography (MSLA) technology. As the name implies, these machines use a standard LCD panel to selectively mask off the ultraviolet light coming from an array of LEDs. Add in a motorized Z stage, and you’ve got a simple and cheap way of coaxing UV resin into three dimensional shapes. These days, $200 USD can get you a turn-key MSLA printer with resolution far beyond the capabilities of filament-based FDM machines.
But [JD] still thinks we can do better. His project aims to produce a fully-functional MSLA printer for $30, and perhaps as low as $15 if manufactured in sufficient quality. He believes that by making high-resolution 3D printing more accessible, it will allow users all over the globe to bring their ideas to life. It’s no wonder he’s calling his machine the Inspire 3D Printer.
A test fixture for the LCD module.
This isn’t just some pie in the sky concept rolling around in [JD]’s head, either. You can order the Inspire Development Kit right now for just $30, though he makes it clear what you’ll receive isn’t quite a functional MSLA printer. By leveraging a common LCD module, the ESP32, and several 3D printed parts, he’s proven his price point for the kit is achievable; but there’s still plenty of work that needs to be done before the machine is ready for the general public.
For one thing, he’s still working the kinks out of the Z movement. The current design is 3D printed, but [JD] says he’s not quite happy with the amount of slop in the movement and is considering replacing the entire thing with the linear actuator from an optical drive. We’ve already seen these parts reused for accurately positioning lasers, so there’s certainly precedent for it. The firmware for the ESP32 is also in its infancy, and currently only allows the user to print from a selection of simple hard-coded shapes as a proof of concept.
[Jan Mrázek] is no stranger at all to home-grown improvements with his Elegoo Mars SLA 3D printer, and there is a lot going on in his experimental multi-LED upgrade which even involved casting his own lens array. In the end it did speed up his prints by a factor of three to four, though he cooked an LCD to failure in the process. Still, it was a fun project done during a COVID-19 lockdown; as usual there is a lot to learn from [Jan]’s experiences but the mod is not something he necessarily recommends people do for themselves.
[Jan] started by wondering whether better print quality and performance could be obtained by improving the printer’s UV light source. The stock printer uses a single large UV LED nestled into a reflector, but [Jan] decided to try making a more precise source of UV, aiming to make the UV rays as parallel as possible.
Custom LED array molded in clear epoxy.
To do this, he took a two-pronged approach. One was to replace the single large UV LED with a 4×7 array of emitters plus heat sink and fans. The other was to make a matching array of custom lenses to get the UV rays as parallel as possible.
Casting one’s own lens array out of clear epoxy was a lot of work and had mixed results, but again, it was a lockdown project and the usual “is-this-really-worth-it” rules were relaxed. In short, casting a single custom lens out of clear epoxy worked shockingly well, but when [Jan] scaled it up to casting a whole 4×7 array of them, results were mixed. Mold deformation and artifacts caused by the areas between individual lenses robbed the end result of much of its promise.
More success was had with the array of UV emitters, which enabled faster curing thanks to higher power, but the heat needs to be managed. The stock emitter of the printer is about 30 W, and [Jan] was running his new array at 240 W. This meant a blazing fast one second exposure time per layer, but the heat generated by the new lighting was higher than anticipated. After only ten hours the LCD failed, probably at least in part due to the heat. [Jan] halved the power of the array down to 120 W and added an extra fan, which appears to have done the trick. Exposure time is two to three seconds per layer, and it’s up to 150 hours of printing without problems.
Again, it’s not a process [Jan] necessarily recommends to others (and he definitely recommends buying lenses if at all possible instead of casting them) but as usual there is a lot to learn from his frank sharing of results, both good and bad. We’ve seen 3D-printed lenses as well as adding WiFi connectivity to one of these hobbyist printers, and it’s great to see the spirit of hacking alive and well when it comes to these devices.
