It’s been more than three months since we revealed the upcoming Original Prusa XL, so it’s time to give you an update on the development and also answer at least some of the most frequently asked questions.

I know these are not the best times to share a dev diary – a war is raging in Ukraine, just several hundred kilometers from our factory, and there are more pressing issues than discussing the features of a 3D printer. We’re trying to help wherever we can and once again I’m amazed by the generosity and support coming from all around. But also we don’t want to keep you in the dark regarding your pre-orders. So, here’s an overview of the current stage of development with more news coming in a couple of weeks, hopefully in better times.

Please understand that we can’t fully disclose everything yet, so if the thing you’re most interested in is not explained here today, it’s likely because that feature is still under development. However, rest assured, that once we’re certain about the exact numbers and specifications, we’ll share them with you in future Dev Diaries.

What’s been happening?

I already covered one major obstacle extensively in the 2021 Recap article, so just in short – the worldwide shortage of various components and materials is affecting our production and development, and the XL is no exception. However, there’s a silver lining to that. The unavailability of the main processor for the XL’s motherboard caused us to look for alternatives. Eventually, we settled on a newer generation of the same chip, which brings a bit more horsepower and allows us to do some extra things with the firmware – like embedding certain information about the machine into the OTP memory, e.g. hardware revision of the board and installed accessories, etc. which will make things like firmware updates more convenient. On the other hand, we’ve lost some time on reworking the firmware to make it compatible with the new CPU…

I also teased that we’re starting our own SMT production line so we can be more independent. The XL features several electronic boards and all of them have been manufactured on our SMT line – this is hugely convenient, especially in these times with uncertain delivery dates and issues with transportation. So while this may not sound very exciting to you, it’s an incredibly important step forward for us.

However, let’s skip to something more visible and practical!

Eliminating the wipe tower

One of the most frequent questions we received was whether the XL will need a wipe tower for multi-material printing. I’m happy to say that we’re on the right track to eliminate the wipe tower in a majority of cases and we have already completed several large multi-material prints that required no wipe towers at all.

To achieve this, we’ve combined the hardware-based advantages of the new extruder with advanced software tweaks (not just wipe to infill) to minimize the amount of filament that flows out of the nozzle during filament changes. Basically, we want to avoid a solution that would require dropping any sort of debris from the nozzle into, e.g., some sort of a container located inside the printer. You would have to constantly think about emptying the “waste bin” – and if you’d forget to empty it, then the debris would start piling up inside the printer. Also, with massive multi-material prints which can go even over 10.000 material changes, there would be a ton of debris constantly.

So we had to figure out a different approach. With the Nextruder on board the XL, we can control retractions and nozzle cooling much more effectively, which gives us the opportunity to eliminate the wipe tower and also prevent the nozzle from dropping bits of plastic into the machine. This way, you’ll save considerable amounts of material, which is useful when, e.g., printing with soluble materials which are generally more expensive.

What’s next?

Right now, we’re focusing on finalizing the Nextruder design and optimizing the printing performance so we can finally share some numbers with you soon. Apart from the Nextruder, the majority of the XL’s hardware is pretty close to the final stage, so we’re currently building a larger number of internal testing units to share with our colleagues in the company who will start testing the new machines.

Of course, the firmware development is also in full swing. Right now, we’re adapting our firmware to new electronics and preparing everything for internal testing. One of the key features is the communication system (think something similar to Plug and play) for the expansion board and tool heads. This process needs to be fully automated, so every time you attach a new tool head, the system will recognize it automatically and assign the correct address to it. The XL uses a completely different system compared to our current models, where the mainboard of the XL needs to communicate with tool-head boards – these small boards contain, e.g., loadcell sensor electronics, so the communication channel is pretty busy, and especially the loadcell sensor requires ultra-fast response times.

We’ve also prepared a handy FAQ for you, so check it out at the end of this article. We’ll be back in several weeks with more updates about the XL’s development. 😉


Orders / e-shop

Q: Will I be able to change my selected tool heads / printer type / payment method / add extra tool heads and materials / change the shipping address etc. before the order is shipped?
A: Yes, by paying the preorder fee, you have secured your place in the queue and your order remains editable. Shortly before your printer is shipped, you will receive an e-mail from us with the request to finalize your order – you will be able to add extra items, change the number of tool heads, change your shipping address, payment options, etc. There’s no need to modify your order right now, please wait for our e-mail.

Q: What is the expected shipping date of the first batch?
A: We’re aiming for Q3 2022

Q: What are the shipping costs for the XL / for the XL with multiple tool heads / for the XL with multiple tool heads and extra filaments?
A: At this point, we cannot estimate the numbers. The shipping rates can fluctuate (e.g., due to the Covid-19 pandemic), plus the hardware of the printer and tool heads is not finalized, which means the final weight may vary. On the other hand, the preorder system gives us more options – we can, e.g., send a large batch of XLs to another location and distribute them from there, which brings shipping cost savings.

Q: Can you tell me what’s my position in the queue?
A: We don’t want to share this information to prevent trading with orders. Once shipping starts, we’ll publish a shipping table with specific dates.

Tool heads / Tool changing mechanism

Q: Will it be possible to upgrade the number of tool heads after receiving the printer?
A: Yes, however, if you want more than two tool heads, you will need to install an expansion card (we will disclose more details about it in the upcoming months – pricing, availability, installation, size, ports, etc.). You can read about the tool changer in the previous article here.

Q: What tool heads will be available and how will they be priced?
A: More information will be provided later once we finalize their design.

Q: Is it possible to design your own tool head?
A: Yes, the design of the quick-swap mechanism can be used to attach a tool head of your own design. However, active tool heads will require users to write their own custom firmware

Q: Is it the E3D Revo / Hemera system?
A: No, we’re using a different (custom) design

Printer dimensions and build

Q: What are the dimensions of the XL?
A: At this moment (!), the dimensions are as follows:

Excluding spoolholders: 504 mm / 19.8 in. (w) × 535 mm / 21 in. (h) × 660 mm / 26 in. (d)

Including spoolholders: 804 mm / 31.6 in. (w) × 535 mm / 21 in. (h) × 660 mm / 26 in. (d)

However, this is only the machine itself. The printer requires extra room around it for correct operation (e.g., space above the printer for PTFE tubes, space on the sides to place/remove filament spools). This is why you should have a space of at least these dimensions to comfortably run the XL:

1100 mm / 43.3 in. (w) × 910 mm / 35.8 in. (h) × 775 mm / 30.5 in. (d) – this is the absolute minimum of space you need to have on your table or shelf to run the XL without issues.

Please note that the dimensions may still change.

Q: What is the print area?
A: 36×36×36 cm (14.1×14.1×14.1 inches)

Q: What is the largest spool the XL can hold?
A: The default spool holders’ width can extend to up to 15 cm (5.9 in). However, you can design your own, if you need larger dimensions.

Q: Will there be an enclosure available for the XL?
A: We’ve already teased the additional draft protection and now we’re evaluating the options for the upper cover for the printer. The combination of the draft protection shield and the upper cover would work as a passive enclosure. We’ll share more information later.

Q: Will the XL be stackable like Prusa Pro AFS printers?
A: No, the XL will require some overhead clearance due to the way the tool heads are connected to the machine.

XL Tech

Q: Is the XL compatible with third-party nozzles? Does it support hardened nozzles?
A: Currently, the XL uses special nozzles in the Nextruder and we’re aiming to provide both standard and hardened nozzles at launch. We expect that third-party nozzles will appear on the market shortly after the launch due to the open-source design.

Q: What is the maximum speed of the XL / How much faster is it compared to MK3S+ / What is the recommended printing speed?
A: All these numbers are being currently adjusted and tested. As we have stated in the previous article, the point of the XL isn’t in beating the SpeedBoatRace. We’re aiming for reliability and high printing quality. However, for those who are looking to find the limits, we’re considering allowing the installation of Klipper firmware (not officially supported from our side).

Q: How loud / quiet will it be?
A: This is largely dependent on the printing speed – see the question above.

Q: What are the max temperatures for the nozzle and heatbed?
A: The nozzle is still being adjusted; the heatbed is generally the same tech as the MK3S+, so the heatbed temperatures are the same.

Q: How well does the Nextruder work with flexible filaments?
A: We achieved excellent results with our testing units 🙂

Q: Is it possible to use multiple nozzle diameters during one print?
A: We’re currently evaluating the pros and cons of a multi-diameter setup, it is something that is on the slicer’s side.