MK4 vs. MK3S+ - Two Days Later
Here are my impressions, two days after having assembled the MK4 kit:
- The assembly instructions, as always, are a brilliant example of how instructions should be written. A monkey with a wrench could do it, given it could read.
Some steps do need prowess, but they are likely to be simplified in further iterations. Read the users' comments below each step before you start doing it!!!
- Nextruder solves the infamous Issue #602 due to the flat contact surface between the filament and the extruder gears. The extrusion consistency is now by far more better. It also reliably handles even very soft TPU filaments, that older models struggled with. On my old MK3S+ I had many failed prints with 82A TPU, due to the heat-creep and tangled filament around the extruder gears.
There is also a sensor in the heat break that detects heat creep and thermal runaways - which is a great feature!
- Printing speed with Input Shaper (5.0.0 RC) is awesome, without any noticeable drop in quality, while normal prints are generally the same or slightly faster than on MK3.
In order to use the IS you have to install the 5.0.0 RC or newer firmware, and Original Prusa MK4 Input Shaper printer profile.
When using IS you will also have to use special filament profiles (suffixed @PGIS) as it requires higher than normal filament temperatures.
I still need to test how it handles ASA, as it would require temperatures around 280° which I don’t feel comfortable using for longer periods of time.
Still there are no official IS profiles for 0.25 nozzle.
- Print size is now the whole 20mm taller, giving you a total of 250 x 210 x 220 mm.
However, due to the taller extruder assembly, if you use a Prusa Lack Enclosure with a concrete tile underneath the printer, you might need to print legs extension and get taller plexiglass sides.
- Nozzle cooling is better engineered on MK4. On my MK3S I had to carefully choose how to Z-rotate some objects, in order to keep the overhangs to the front to ensure better cooling. On the MK4, the prints start showing issues only above 60° overhangs - no matter how you turn the object.
- I love the LoveBoard, and you will too (I guess that's how they got the name). Working on the extruder without having to disassemble the cables and the X-axis is a great improvement. I can now replace the nozzle within a minute, without any tools and without fearing that I would break something in the process!
If you need printing with additional nozzles, I recommend buying an extra nozzle assembly for each (heater block + heater + sensor + nozzle). It is not cheap, but it will save you money on the long run.
- The Color LCD display looks great. It is a bit slow, but I can work with that. The LED status light is also cool, but some users will want to turn it off.
The printer lets you customize what information you want displayed in the footer, but I would also like to have a possibility to swap the header and the footer, and/or to have the same items added to the header.
No touch screen support in the firmware yet, but looking forward to it.
- Bed leveling is much better. It probes only the area occupied by the print, ensuring a better first layer on the print. As the nozzle very gently taps against the surface to find the bed, it eliminates the need for manual "Live Z-Adjust", as it now exactly knows where the surface is. It also eliminates magnetic interference that PINDA had to take care of and allows you to print on non-ferrous materials. It also does a strange, but efficient procedure that detects and cleans the head from the filament ooze. Therefore, the "skirt" that was used mainly to stage the nozzle is no longer needed, which leads to effectively bigger print surface.
The result is an almost perfect print on a smooth, silk and the textured plate, without having to change any settings in the printer.
The procedure sometimes leave tiny dabs of filament on the print surface that can be noticeable on smooth and silk prints. It’s a pain, that I hope would be fixed soon.
These pre-print steps also take a few minutes more than MK3, as the printer moves the temperature down to 170° and back to 210° (for PLA) to prevent filament from oozing.
Speaking of the strain sensor, it could also be used to detect issues like clogged nozzle and prints getting detached from the print bed, so hopefully we might see that feature too.
- Printer Sock now sits much tighter, as the wires don’t pass through its sides. On MK3 it used to curl and “peel off” after some time. There is also an option in firmware to set when there is a sock installed (I guess it affects the heat monitoring algorithm). The Nextruder socks are now even available on Prusa Shop.
- Noise during the print is pretty much the same as on MK3 in "Silent" mode. So yeah, it is quieter.
When using Input Shaper, it gets somewhat louder, but it is still a very quiet printer that shouldn’t bother you or your neighbors much during the nightly prints.
- PrusaLink (local web UI) and PrusaConnect (cloud remote control) are a great alternative for OctoPrint. There are still things to be desired (like sorting by time instead of just by name), but it’s a work in progress. It is great that MK4 comes with built-in Ethernet and Wi-Fi module.
On my old MK3 I had a Wi-Fi SD card that appeared on the network as a DavWEB shared directory. It would be nice if PrusaLink added that as well, because I'd rather have an option of a network directory, instead of having to use a web interface to transfer files.
Web camera support is currently poor. We need the possibility to attach any web cam to the printer! It can, and hopefully will be done.
- Instead of standard spacers, the print bed is attached by “expansion joints” that should minimize warping of the bed when it gets hot.
I haven’t seen the actual measurement results as I could with my old OctoPi & Nylock Mod, but I’d very much like to.
Overall, I don’t think I’ll ever regret changing my old MK3S+ for MK4.
RE: MK4 vs. MK3S+ - Two Days Later
- PrusaLink (local web UI) and PrusaConnect (cloud remote control) are a great alternative for OctoPrint. There are still things to be desired (like sorting by time instead of just by name), but it’s a work in progress. It is great that MK4 comes with built-in Ethernet and Wi-Fi module.
On my old MK3 I had a Wi-Fi SD card that appeared on the network as a DavWEB shared directory. It would be nice if PrusaLink added that as well, because I'd rather have an option of a network directory, instead of having to use a web interface to transfer files.
Web camera support is currently poor. We need the possibility to attach any web cam to the printer! It can, and hopefully will be done.
Great overview, thank you! Quick question - with the MK4, do you still have the option to use Octoprint or do you have to move to Prusa Link / Prusa Connect ? I have multiple printers on Octoprint, and I would prefer to keep the MK4 on that as well.
Prusa is MK4S w/ MMU3 (formerly MK4 / MMU3, MK3S+/MMU2), 2 Prusa MINI+, Octoprint. PETG, PVB, (some) PLA.
RE: MK4 vs. MK3S+ - Two Days Later
Great overview, thank you! Quick question - with the MK4, do you still have the option to use Octoprint or do you have to move to Prusa Link / Prusa Connect ? I have multiple printers on Octoprint, and I would prefer to keep the MK4 on that as well.
Thanks, these are the questions that I've been wondering before I got my hands on it.
As I said, at the time being, OctoPrint can not connect to MK4, so you will have to use PL/PC. Hopefully the good people that work on OctoPrint would solve that in the foreseeable future.
RE: MK4 vs. MK3S+ - Two Days Later
Correction: Compared to MK3, the Z height on MK4 is 10mm taller, not 20mm.
RE: MK4 vs. MK3S+ - Two Days Later
As I said, at the time being, OctoPrint can not connect to MK4, so you will have to use PL/PC. Hopefully the good people that work on OctoPrint would solve that in the foreseeable future.
That is incorrect. Octoprint can connect and print on the MK4. I use it every day!
There are some features missing from the MK4 firmware that impact certain capabilities. For example, the MK4 does not communicate "filament runout" to Octoprint, so Octoprint does not know when filament runs out. And MK4 firmware doesn't implement M117 for status, or M23/24 commands for selecting/starting a print of Gcode stored on the USB stick. Prusa has said these items are "on the todo list" but have not yet provided a schedule.
RE: MK4 vs. MK3S+ - Two Days Later
If you need printing with additional nozzles, I recommend buying an extra nozzle assembly for each (heater block + heater + sensor + nozzle). It is not cheap, but it will save you money on the long run.
This was my plan when I bought the MK4 -- it seemed like having complete assemblies (nozzle, heatblock, heater, thermistor) would make swapping easier.
But after trying both ways, I have decided it is easier and faster to just swap the nozzle. The nozzle swap can be done without removing the heater block or wiring (i.e., just loosen the thumbscrews, hold the heat block, and replace the nozzle). I found disconnecting/reconnecting the wires, and tucking them into place, was more hassle than just grabbing wrenches and swapping the nozzle in the existing block. The one-piece nozzle/heatbreak/feed-tube allows a cold-swap, so much easier than on previous models!
RE: MK4 vs. MK3S+ - Two Days Later
Same here. I spent the money on heater blocks, thermistors, and heater elements but after a few weeks I've come to the conclusion that it's much easier and faster to just swap the nozzle. The way the print fan is mounted on the Mk4 makes it so much easier than on the Mk3s. On my XL it took less than ten nozzle swaps using the "replace the whole hotend" approach to break a thermistor cable as they need to be pushed through the hotend to go up to the board. I switched to just replacing the nozzle like I do on the Mk4 and haven't had an issue since.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE:
Still there are no official IS profiles for 0.25 nozzle.
Update: I see there is one now.
RE: MK4 vs. MK3S+ - Two Days Later
- Instead of standard spacers, the print bed is attached by “expansion joints” that should minimize warping of the bed when it gets hot.
I haven’t seen the actual measurement results as I could with my old OctoPi & Nylock Mod, but I’d very much like to.
I found the way to see the actual Z position (Footer>>Item ...>>Z) of the head and the "nominal" current layer heigh (Footer>>Item ...>>Z-height). So in order to see if the print bed is perfectly level, you can observe how the first value changes against the second value, when the print bed moves.
For example, while printing the Spatula that came with the printer, I saw that on the first layer (Z-height: 0.2), the actual Z was changing from around 0.05mm when the head was on the leftmost position, to 0.15 when it was on the rightmost. Then I manually turned the left Z-motor by 2 clicks counter-clockwise, and then it straightened, so the values now change between 0.13 and 0.16mm.
So, yeah, I would really still like to have the good old Nylock Mod as an option for manually leveling the bed. Even though the head movements compensate for the slant in order to get a uniformly thick first layer - that way the imperfections just reflect to the printed model. Having the bed leveled properly is my way to go.
RE: MK4 vs. MK3S+ - Two Days Later
jonnieZG did you test pla and pet? Does the printing improve on them too and is 602 resolved? Thank you.
RE: MK4 vs. MK3S+ - Two Days Later
jonnieZG did you test pla and pet? Does the printing improve on them too and is 602 resolved? Thank you.
As I said in the first post, the 602 is gone. Tested ASA, PETG, PLA and FLEX. Still did not try Nylon.
The contact surface between the extruder gears and the filament is now flat, and the 32-bit controller also allows much more precise control - so the extrusion is much more consistent. Combined with the significantly more precise bed probing, the print is visibly smoother.
RE: MK4 vs. MK3S+ - Two Days Later
This was my plan when I bought the MK4 -- it seemed like having complete assemblies (nozzle, heatblock, heater, thermistor) would make swapping easier.
But after trying both ways, I have decided it is easier and faster to just swap the nozzle. The nozzle swap can be done without removing the heater block or wiring (i.e., just loosen the thumbscrews, hold the heat block, and replace the nozzle). I found disconnecting/reconnecting the wires, and tucking them into place, was more hassle than just grabbing wrenches and swapping the nozzle in the existing block. The one-piece nozzle/heatbreak/feed-tube allows a cold-swap, so much easier than on previous models!
Same here. I spent the money on heater blocks, thermistors, and heater elements but after a few weeks I've come to the conclusion that it's much easier and faster to just swap the nozzle. The way the print fan is mounted on the Mk4 makes it so much easier than on the Mk3s. On my XL it took less than ten nozzle swaps using the "replace the whole hotend" approach to break a thermistor cable as they need to be pushed through the hotend to go up to the board. I switched to just replacing the nozzle like I do on the Mk4 and haven't had an issue since.
Very interesting. Do you have a silicon sock on the heater block? I imagine having a sock on will not make it this as easy to accomplish, as I assume it will have to be removed in order to screw the nozzle off.
But I'm also worried about the cables breaking or the sockets on the loveboard wearing out if swapping out the whole assembly every time. Really unsure what to do, as I want to order more nozzles. I guess I should practice taking out the one nozzle I have from the heaterblock and putting it back in, to see how easy I find it.
RE: MK4 vs. MK3S+ - Two Days Later
You know, silicon socks are like religion, you believe in them or you don't. I'm a sock atheist. But even if you have a sock on, it's what, a tenth of a second or so to pull it off, so no real time added to the process.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE:
I'm a sock believer, at least with the Nextruder heatblock, since the sock is very secure and can't slip down (that was sometimes a problem with other designs). But as @fuchsr says, it takes very little time to remove/replace the sock -- might add 5-10 seconds, at most, to the entire operation.
The nozzle-to-heatblock interface does need to be clean (free of plastic) before unscrewing the nozzle. If there is plastic stuck around there, you need to heat the nozzle, clean off the plastic, and cool it down again before removal. A sock can eliminate that step, assuming it protects the nozzle-to-heatblock interface from errant plastic (some are designed better than others in that respect). But if you monitor your prints, and take care of issues like stringing, over-extrusion, or a spaghetti situation, then there won't be any errant plastic to worry about.
RE: MK4 vs. MK3S+ - Two Days Later
Thank you for this info! I am reading before my Mk3 to Mk4 kit gets here and since I have the lack enclosure, this is key that I print taller lack leg connectors to modify the enclosure before disassembly as well as the printed parts...
"Print size is now the whole 20mm taller, giving you a total of 250 x 210 x 220 mm. However, due to the taller extruder assembly, if you use a Prusa Lack Enclosure with a concrete tile underneath the printer, you might need to print legs extension and get taller plexiglass sides."
Strange women, laying in ponds, distributing swords, is hardly a basis for a system of governance!
RE: MK4 vs. MK3S+ - Two Days Later
I have two Mk4's in lack enclosures, with a paver stone. No need for any extensions, unless you're planning on using an MMU. Even then I'm not sure you need any. Of course I assume we're talking Lack v2.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE: MK4 vs. MK3S+ - Two Days Later
I have had MK3S before, and I usually ran it with Stealth Mode on, for overnight prints. MK4, without stealth mode, even without IS, is noisier (concrete block, pads etc) and effectively blocks me doing this.
For me this is the drop that tilts the balance in favor of MK3S, regardless of its slowness. Not to return, of course, but to be unhappy, generally speaking, and use it less than before. I'm on my way to install the 6.0 RC now, that adds a stealth mode...
RE:
Lack v2
What is Lack v2 ? I just can buy these here in Germany:
LACK Beistelltisch, weiß, 55x55 cm - IKEA Deutschland
RE: MK4 vs. MK3S+ - Two Days Later
V2 doesn't refer to the table itself but the printed parts: https://www.printables.com/model/3673-prusa-enclosure-v2-mmu2s
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...