My last major update article came out in May and it’s almost unbelievable that six months have already passed. We’re still in the middle of the COVID-19 pandemic, but despite the new challenges, we are still moving forward. Truth be told, we were expecting that we would be working on something entirely different by now – like putting finishing touches to the XL and the successor to the Original Prusa i3 MK3. However, the current situation makes sourcing new parts much more difficult and we have to find new ways to solve various problems.

So even though we’ve made major progress on our “next-gen” machines, we’re not ready to show them at this very moment. We have something else, though: I would like to announce that the improved models of our 3D printers, the Original Prusa i3 MK3S+ and the Original Prusa MINI+, just arrived! We also have a new type of print sheet, the Black Friday deals are nearly here and that’s still not all. We started shipping both the MK3S+ and MINI+ last week in secret, so some of you probably already have them 🙂 So, what’s new?

Introducing MK3S+, MINI+, and MINI+ KIT

Even though the MK3S and MINI are established as workhorses for quite some time, we want to push the reliability of our 3D printers even further and make their assembly process faster and easier. The new MK3S+ features a number of smaller design changes and features a new Mesh Bed Leveling sensor, the SuperPINDA. This sensor is now also featured in the MINI (replacing the basic M.I.N.D.A. sensor), turning it into the MINI+. This is a big step forward for the MINI since it makes the calibration of the first layer much more consistent.

When we announced the MINI back in October 2019 with the launch in December, we wanted to bring an affordable, yet fully-equipped and reliable 3D printing workhorse. The demand was (and still is) huge and we’re constantly hiring to bring down the lead times – there are almost 600 of us, wow! We were excited to see all the positive comments and reviews. However, we did not want to rest on our laurels – there were also suggestions on what could be improved, both on the hardware and software side. So while our firmware team keeps bringing new software features (such as the upcoming Sheet profiles for the MINI in firmware 4.3), the rest of the dev team focused on hardware changes. The most important change is the upgrade of the M.I.N.D.A. sensor, which was pretty much the same sensor we used on the MK2S e.g. it comes without temperature compensation. However, it enabled us to reach such a compelling price point. It is now replaced by the new SuperPINDA, which doesn’t suffer from temperature drift and makes the first layer consistent – for example if you are running one print after another, but set the Live Adjust Z with a cold printer.

So, before we get to details, let me say that most of these changes are not major enhancements that would drastically change the behavior of our printers. Think of them as a “reliability upgrade” which is based on the feedback we received from the community, and also by running our printers nearly 24/7 in our print farm. Basically, if your MK3S prints without any issues, the upgrade won’t bring any significant print quality improvements. Nevertheless, some of the changes will definitely make the assembly process and regular maintenance easier, and even improve the user experience with the MINI+.

However, we had to make a tough decision. While the price of the MK3S+ stays the same, the price of the MINI+ has been increased by 50 USD / 40 EUR (VAT incl) – that’s 399 USD / 419 EUR (VAT incl). When we calculate the price of our products, we take into account many different factors – the costs of materials, manufacturing costs, additional costs (e.g. tech support) + potential additional costs such as fluctuating exchange rates. However, the COVID-19 pandemic changed a lot of things, and often for the worse. We have trouble sourcing certain parts, some parts are now more expensive, the shipping costs are higher – just to name a few. The second reason is the increased price of the new SuperPINDA sensor made of higher-quality parts.

I understand the price of the MINI is a big plus for many of you, so we were looking for ways to compensate for this. So, first of all: based on the results of a survey we’ve sent out this year, we decided to introduce the MINI+ Assembly KIT for 349 USD / 379 EUR (VAT incl.). The MINI+ KIT will bring the same experience as the MK3S KIT because many of you miss the opportunity to build the MINI screw by screw, which is the best way to learn everything about the machine and how it works. We’ll bring you the KIT in early 2021, but you can visit the store page right now and use the “Notify me when available” option to receive a notification once the KIT becomes available. Another chance to save on the MINI is to take advantage of our upcoming Black Friday deal: we will offer free shipping on the MINI+ (and other products – more details below), which will effectively bring down the total costs of your purchase. For many countries, this can make a 40 USD difference.

And I think it goes without saying that everybody who is currently waiting for their MK3S/MINI to be shipped will get the MK3S+/MINI+ automatically! 😉 

Let’s dig into the details!

SuperPINDA (MK3S+ and MINI+)

So, while most of the changes are relatively minor, the SuperPINDA, which replaces the P.I.N.D.A. V2 and M.I.N.D.A., deserves more space. What’s the difference apart from the obvious lack of dots? Compared to the older models (and especially the M.I.N.D.A. sensor), SuperPINDA is temperature-independent, features a much higher quality sensor and better quality components overall, plus, it does not need a thermistor. Technically there is still a certain temperature dependency, but nowhere near any significant levels that would affect the measurements. Especially the owners of the MINI should see noticeable improvements in the consistency of the first layer with the new sensor. On the other hand, the difference between the MK3S and MK3S+ will be fairly minor. Please note that if you decide to replace the P.I.N.D.A. V2 on the MK3S with the SuperPINDA, you need to flash firmware 3.9.2 (or newer).

To give you a little background on the development: we’ve been working on a new type of sensor since the beginning of 2020. The very first version of the sensor came out with the MK2 (the MK3/S features an improved V2 version) and it allowed us to implement the extremely useful Mesh Bed Leveling feature. It is designed to smooth out the tiny imperfections of the first layer introduced by the assembly and part tolerances stacking up. However, we knew we could push the consistency and long term reliability.

The P.I.N.D.A. sensor features a thermistor used for thermal compensation. However, we wanted to get rid of the thermistor (because it depends on averaged values) and improve the overall accuracy of the sensor in repeated measurements. To explain: when the Mesh Bed Leveling routine runs, the sensor probes several points on the print sheet, and the measured values are further compensated from the lookup table based on thermistor values. The sequence is repeated several times and averaged based on the user-selected MBL configuration. This was the process we wanted to focus on.

Of course, this brought new challenges: how to improve the accuracy and repeatability of the measurements, while keeping the runtime of Mesh Bed Leveling at a reasonable level – and without the need to rework the extruder? We went through at least five different redesigns and made thousands of measurements until we finally found the right combination. The improved consistency and overall quality of used components is a major jump forward – you can see the measured values for five different SuperPINDAs in the graph below.

It also features a higher quality cable – significantly thinner strands of copper wire will last much longer even with constant bending motion. According to our statistics, when the mesh bed leveling failed, the sensor itself was not the cause, but it was usually caused by the cable.

The SuperPINDA sensor was originally meant only for the MK3S, however, the feedback on the MINI has shown that users would love to have the same “set it and forget it” behavior as on MK3S even at a slightly increased price. This is why we have decided to put the very same next-generation SuperPINDA into the MINI as well, even though it is partially responsible for the 50 USD / 40 EUR price increase. I fully believe it’s worth the price, though. The MINI+ also features new clips that hold the bearings.

SuperPINDA FAQ

Q: Will P.I.N.D.A. V2 and M.I.N.D.A. remain in stock?
A: Once the current stock runs out, they will be completely replaced by SuperPINDA. SuperPINDA will be the new replacement part for MK3/S/+, MK2.5/S and MINI/+. First generation P.I.N.D.A. (for MK2 variants) will remain in stock.

Q: Do I need to upgrade the current sensor with the SuperPINDA to have better quality prints?
A: No. If your printer runs perfectly fine, there’s no need to replace the part.

Q: Is the SuperPINDA compatible with the MK2.5/S?
A: Support will be added in a future firmware update.

Y and X Axes (MK3S+, partially MINI+)

Two major things happened on the Y-axis of the MK3S+. The smooth rods are no longer held by zip-ties. Instead, we designed a new set of robust plastic holders. And another important thing: the U-bolts which were used to secure the Y-axis bearings are gone, too. Instead, there’s a new set of metal clips, which are easier to mount and provide slightly better support for the bearings (the MK3S+ uses Misumi bearings). These are the same clips that are present on the MINI+. However, these clips do not bring any print quality improvements and their only purpose is to make the assembly easier – we do not recommend replacing them on an already assembled printer. This is why they are not included in the MINI+ upgrade kit (which consists of the SuperPINDA only).

There is only one small (yet very useful) change on the X-axis of the MK3S+. The new X-end part is reinforced and features a different tensioning mechanism.

Extruder changes (MK3S+)

A number of smaller changes occurred around and in the extruder. The filament path is slightly altered with the aim to make printing (especially flexible materials) more reliable. The filament sensor lever (FS-lever) has a modified design for improved reliability and the idler door has a greater opening range to allow for easier access to the Bondtech gears.

Apart from this, there’s a number of minor improvements related to the heat resistance of extruder parts. The fan shroud has two attachment points instead of one and the cooling/airflow, in general, has been slightly improved.

Upgrade kits FAQ

Q: What’s included in the MINI+ upgrade?
A: The SuperPINDA sensor only. The bearing holders (metal clips) bring no benefit in terms of print quality or reliability, so they are not included

Q: What’s included in the MK3S+ upgrade?
A: SuperPINDA, Bearing Clips for Y-axis bearings, IR filament sensor+cable, Hotend PTFE tube, Fan shroud printed from ASA, PETG filament to print the plastic parts

Q: I have the MK3S and want to buy the MMU2S. Do I need to buy the MK3S+ upgrade as well?
A: No, the MMU2S is fully compatbile both with MK3S and MK3S+. No additional purchase apart from MMU2S is necessary.

Q: I have the original MK3 (not MK3S) and want to buy the MMU2S. What should I buy?
A: You will need the MMU2S and also the MK3S+ upgrade (sold separately).

Q: I have the MK3, do I have to upgrade to MK3S and then to MK3S+?
A: No, you can upgrade directly from MK3 to MK3S+. Everything from MK3S upgrade is already included in the MK3S+ upgrade.

Q: When will the printable files (STL / 3MF) for new parts become available online?
A: We will add them in the upcoming days.

Upgrade kits coming later, the “2.5” upgrade packages discontinued in December 2020

While all of the changes are aimed to improve the ease of assembly and user experience, the upgrade itself is not necessarily a must, especially for the MK3S. In other words: if your printer runs and prints without any issues, you will not gain any significant print quality improvements by upgrading to “Plus”. This is why we have decided to start shipping the MK3S+ upgrade package early next year and not immediately. However, you can pre-order them from our e-shop right now. The major difference between the MINI and the MINI+ is the SuperPINDA sensor, which is already available on our e-shop.

The upgrade process for “i3” 3D printers will be simplified:

  1. There will be one MK3S+ upgrade kit, both for the MK3 and MK3S
  2. If you have the MK3 and want to add the MMU2S upgrade, you also need to purchase the MK3S+ upgrade kit (separate purchase).

Since the number of hardware combinations keeps growing, we have decided to discontinue the “2.5S” upgrade kits – these will be available only until the end of December 2020, so if you still want to upgrade your old MK2/S in the most convenient way, consider upgrading as soon as possible. However, this does not mean we would completely stop you from upgrading – separate parts for the upgrade will be still available through our e-shop and we will publish a detailed guide on how to purchase the parts separately and upgrade your MK2/S.

And finally, to make the transition smoother, the MK3S+ and MINI+ will use the same firmware as the MK3S and MINI, respectively.

Introducing Satin Steel Sheets for the MK3/S/+

Our double-sided spring steel sheets introduced with the MK3 are one of the things that make living with a 3D printer so much easier. Currently, we’re offering two types – smooth and textured sheets. Some of you may remember, though, that back in 2017, we were actually planning a third one: the glossy powder-coated sheet. While we eventually decided to launch only two sheets, the idea of a third one kept floating around.

Our very talented team members in our “secret lab” on the outskirts of Prague spent more than a year perfecting a brand new formula and I’m happy to announce that the result of their hard work is finally here: the Satin powder-coated PEI spring steel sheet! Our intention was to create a print sheet with properties between the smooth and textured sheets. The kind of surface that would be appreciated by those who often print PLA and PETG. The (very general) rule of thumb is that the smooth sheet works better for PLA and the textured one should be used for printing PETG. This is recommended due to the fact that PLA may have adhesion issues on the textured sheet. PETG, on the other hand, may stick too well to the smooth sheet and cause damage when you try to detach the print. The satin sheet is a good option for printing both PLA and PETG – once a fresh print cools down, it detaches by itself in most cases.

The first layer printed on the Smooth (left), Satin (middle), and Textured (right) sheets, same in the bottom row – only zoomed in

The entire Satin sheet is manufactured completely in-house using our own, internally developed methods. The surface of the satin steel sheet has a very fine texture, which is lightly imprinted in the printed object. This sheet is manufactured in a similar way as the textured powder-coated sheets, however, it has a different surface finish resulting in better adhesion and the signature matte appearance. This is why we call it a “satin” sheet.

Of course, you can use this sheet with a vast majority of common filaments – no matter whether you want to print with ASA, Polycarbonate, Polypropylene, flexible filaments or even Nylon, this sheet can handle them all. For example, Flexfill98A can be printed even without a separation layer. However, smooth and textured sheets may still be better for certain filaments – check our material guide to learn more. The maintenance is very similar to the textured PEI powder-coated sheet. It’s very simple, just don’t forget to read the instructions. 😉

We will offer the first batch of Satin powder-coated sheets on our e-shop in very limited quantities (check out the store page here) with the next batch scheduled for early 2021. And we will also bundle them with the first 300 MK3S+ 3D printers ordered during the Black Friday sale, for free.

Satin Sheets FAQ

Q: Will the satin sheet be available for the MINI/+ as well?
A: Yes, in 2021

Q: Will the satin sheets be added to sheet profiles in the firmware?
A: You can add them any time using the “Rename” option

PrusaPrinters.org News – 3D model viewer and more!

We’ve shared the last major updates on the PrusaPrinters community hub back in May, however, we haven’t been slacking off in the past six months – on the contrary! There’s been a number of awesome creator contests, and we also continue to improve the code and add new features.

We added things like mentions in comments (with the @ symbol), expanded the range of supported files, improved the search function, implemented likes for prints and collections, added spam protection…

And that’s not all. The very recent changes include things like sorting prints in your collections, increased number of collections (from 9 to 20) and above all: adding static and interactive full 3D previews for STL, 3MF, OBJ and Gcode files! We hope this will make navigation among 30.000 projects a bit easier. 😉

New filaments in our Prusament line-up

We also keep adding more new materials to our ever-expanding lineup of high-quality filaments. Starting this Thursday, we’re adding two shiny new materials: The “Oh My Gold” and “Viva La Bronze” PLA Blends. Check out the entire selection at Prusament.com or in our e-shop. We offer plenty of exciting PLA colors, durable ASA and PETG filaments, and even the advanced PolyCarbonate Blend. And you can, of course, see a detailed report on every spool manufactured online. 😉

Black Friday and Cyber Monday deals

As usual, we will join the worldwide Black Friday and Cyber Monday craze with attractive deals in our e-shop!

Start: November 26th at 4.00 p.m. (PST) / November 27th at 12.00 a.m. (GMT) 

End: December 1st at 12.00 a.m. (PST) / December 1st at 8:00 a.m. (GMT)

You can expect the following deals:

  • MK3S+ (kit / complete) – free shipping, free steel sheet (first 300 customers will receive the satin sheet, the rest will get a powder-coated sheet), free spool of Prusament PETG Galaxy Black
  • SL1 (kit / complete) – discounts on printers (see below), free shipping, one extra 1kg bottle of Azure Blue Tough resin for free (one bottle is already included in the package, so you will get two bottles in total)
    • SL1 kit – 250 USD / 250 EUR / 5000 CZK off
    • SL1 complete – 200 USD / 200 EUR / 4500 CZK off
    • SL1 kit + CW1 bundle – 250 USD / 250 EUR / 5000 CZK off
    • SL1 complete + CW1 bundle – 200 USD / 200 EUR / 4500 CZK off
  • 20% discount on smooth and powder-coated PEI spring steel sheets
  • Free Basics of 3D Printing book with every MK3S+ (available in EN, FR, IT, GER, ES, CZ and PL) – This is a great gift to your friends if you are already savvy with 3D printing
  • Free shipping on orders over 200 USD/EUR (conditions may apply)

Update 25/11/2020: since you kept asking about filament discounts: due to a shortage of materials from our suppliers, we cannot manufacture enough PLA Prusaments to satisfy the increased demand. In general, the demand for Prusament is very high and our manufacturing capacities are running at max. Discounting the materials would result in increased lead times.

What’s next?

If you want to learn more about all the things from this article, be sure to tune in for our regular PrusaLive podcast on Wednesday, November 25th (9 p.m. CET / 8 p.m. GMT / 12:00 p.m. PST), where I will discuss all the details with my colleagues and answer questions from the chat!

Also, I understand some of you might have been expecting news about upcoming 3D printers – I assure you that they’re coming. However, like many others around the world, we’ve been affected by the COVID-19 pandemic as well. All of us are facing new challenges. We’re doing our best to ensure a safe working environment for the entire team – and for others, too. We still manufacture protective face shields, because the COVID-19 pandemic is far from over and it puts a huge strain on everyone around the world.

We are working hard so we can share news about our upcoming machines soon. In the meantime, I hope you will enjoy using not only the new sheets but also the MK3S+ and MINI+. And BTW – because we have more time to work on the XL, we decided to add tool changing to it 😉

Happy printing!

Jo Prusa