Thoughts on 32-Bit and MK3S+
Quick introduction, I recently purchased a Mini+ to replace a FlashForge Adventure 3 that kind of worked, but was never completely sold on it. In fact I was ready to give up on the hobby because of how "meh" everything turned out. Stuff just never came out "right" for me. For the longest time I thought that's just 3D printing. But with the Mini and in just a few short weeks I'm back in love with the hobby and making all kinds of things, both for fun and functionality. I'm now at a point to where I need an enclosure for some of the projects I want to do, and there are some things that are just too big for the Mini. I have an XL on order, however I didn't put a deposit down until June of this year. I'm guessing it'll be at least a year before I see one.
I've been kicking the idea around of purchasing a MK3S+ but I keep getting hung up on the archaic 8-bit processor. Reading the recent issues Prusa is having sourcing 32-bit controllers for the XL, I think it's going to be a while before we see a "MK4" with a 32-bit controller. I just "discovered" Octoprint on the Mini and impressed with what information it provides and what you can do with it. I'm now starting to think who cares if it's only 8-bit?
I know there are probably hundreds of thousands of 8-bit Prusa's out there, however I don't want to make a purchase now on something that's probably reaching it's developmental end of life. You all know Prusa, and how things work better than me, should I be concerned about spending $1800 (after shipping to the US) on a printer with an 8-bit controller in 2022? Is there a 32-bit controller around the corner?
Mini+MK3S+XL 5 Tool
RE: Thoughts on 32-Bit and MK3S+
My advice: stop thinking about it as a computer, start thinking about it as an appliance. Do you care what's running on your washing machine? It's not like it's going to stop doing what it is doing well now just because it's running an "old" microcontroller. The 8-bit architecture limitations are relevant for the firmware developers - they have to jump few more hoops due to the limited resources but unless you intend to get involved in that - who cares? Also, don't buy it on the premise of what you think it could be doing in the feature: make your decision based on what it is right now and any feature developments are just a bonus.
RE: Thoughts on 32-Bit and MK3S+
The way I know Prusa, the worst case to happen if they stop supplying 8-bit boards as spare part would be that they offer an 32-bit board upgrade option, which would probably be hardly more difficult to install than simply replacing the 8-bit board with the same (+ installing/updating firmware).
There are some limitations with 8-bit boards but I am not aware that print performance or quality is impacted negatively by it. The one big thing Prusa printers are missing is input shaping. But for that you need more computing power, ie a Pi and also something better than a 1st generation Pi zero.
If Prusa were to go rogue and not offering anything of that sort, one could still buy for fairly little money a Bigtreetech board and a Pi (both together for less than 100 EUR or so) and turn the Mk3s into a Klipper run machine.
PS: How do you end up with 1800 USD for an MK3s? Is shipping+tarifs 400 USD? Wow, I bought my kit just 3 years back for 760 EUR or so incl. taxes, free shipping (ok, being in Europe helps and the kit does cut costs too).
Mk3s MMU2s, Voron 0.1, Voron 2.4
RE: Thoughts on 32-Bit and MK3S+
I'm with Zbigniew — even though it's a legitimate question to ask, in practice the 8 bit board is nothing to worry about. The Mk3S+ is a tried and true workhorse. Would I like to see a color LCD? Sure. Would more memory on the board allow the devs to add new features? Sure. Will a 32-bit board improve print quality? Not by itself. Or at least not dramatically. Of course, a Mk4 will have a 32-bit board but what I'd be a lot more excited about is to see other features of the XL be brought over to the Mk4, such as the Nextruder design.
Having said that, I have a hard time seeing Prusa come up with a Mk4 any time soon, given the headaches they're having from sourcing materials for the XL. They're not a big company, I can't really see them add more to the current pain by rolling out a new printer on top of the XL.
On the other hand…
For a while I was convinced that there wouldn't be a Mk4. A Mk4 sort of implies an upgrade path from the Mk3S+ but I thought they'd move away from the bed slinger model and their next "normal sized" printer would be a core XY like the XL but smaller and with only one or two nextruders. Now I'm not so sure anymore. It feels like they have to come out with something and can't just sit idle, but with ongoing world-wide supply chain issues, maybe some smaller upgrade to the Mk3s+ (like a 32 bit board) would address that issue as the bulk of the printer would still be the same.
RE: Thoughts on 32-Bit and MK3S+
You all bring up good points. Thank you for the input and advice.
@thejiral The assembled version is now $1,100 USD. I thought about purchasing the kit to save some money, I use to build PC's, but now with kids and limited time, I would rather spend the time learning Fusion 360 for the project I have in mind.
Mini+MK3S+XL 5 Tool
RE: Thoughts on 32-Bit and MK3S+
^^ Yes 1100 USD sounds less shocking. I agree with you, with kids and limited time you can spare in one go, the complete printer is probably the better option. It is a pain if you can build only in 1h sessions or so and a nightmare if you have to clean up the mess in between. Better invest a few 100 USD more and be able to start basically right away. The advantage of the kit is a better undertanding of the machine which helps later during maintenance but really, there are so many maintenance manuals for Prusa printers that you don't have to rely on that knowledge.
Mk3s MMU2s, Voron 0.1, Voron 2.4
RE: Thoughts on 32-Bit and MK3S+
I should have mentioned the kids play hockey. Two of them are on two teams each. The MK4S+ and XL2S+ would be out before I finished. 😆 With years under my belt as a manufacturing engineer, I think I've finally learned to ask a stupid questions before I bust a tab off something, or do some other similar stupid thing like that. I just want to print. 😉
Mini+MK3S+XL 5 Tool
RE: Thoughts on 32-Bit and MK3S+
Asking for a 32 bit MK3 is not like asking for a 32 bit dishwasher.
8 bits limit how much memory you can access. See the very, very long thread on what you want next in the 8 bit firmware. The limit is how much memory a feature needs. There is no room for more stuff.
Why can’t, for example, the wisdom of the enormous Life Z My Way thread be built into the firmware? Because their ain’t no room. The firmware first layer calibration feature is dog poo, but no way to fix, because a fix won’t fit.
Don’t trust forum advice.
RE: Thoughts on 32-Bit and MK3S+
The link I had for this no longer works, but a couple of years ago there was somebody offering a so-called drop-in 32 bit Einsy/Rambo replacement for Reprap (including Prusa) printers. I have no clue what happened to that effort.
On the Reprap forum (not that active) there have been off and on discussions of driving printers directly from Raspberry Pi boxes, using external stepper drivers and I/O expanders, of course. Those who try this seem to drop out of sight or go (back) to the 'traditional' 8 bit Arduino type solutions.
Personally, I don't care how many bits it has or what kind of a platform it runs on, just so it delivers consistently good prints. So far, my MK3S has done just that with little futzing around and very little down time.
RE: Thoughts on 32-Bit and MK3S+
The 12mhz 8 bit board cannot compete with a 100mhz 32bit board. Yes the 8 bit board works but it will not give you the gcode resolution capabilities a 32bit board setup with 0.9 degree steppers can.
I recently upgraded my X & Y steppers to 0.9 degree Moons and I found out later while modding my firmware that you have to reduce the microsteps from 16 to 8 or else it will overload the Einsy board. See the attached screenshot of my firmware and read the Kuo comments.
Also see the photo comparing the same STL printed on Mini vs MK3s+ (3/4 Down the forum page)
https://forum.prusa3d.com/forum/postid/572413/
The more bits the higher your print resolution is, simple as that.
RE:
Edit* 10kHz for 8 bit not 12mHz*
"the obvious difference is that PandaPi control the motor directly.the gpio on the RPi speed being able to signal at 10+ Mhz as compared to 8/32bit MCU limit of about 10Khz/200khz for steps.that is one of my reason to explore this project. although the <100Khz speed is enough for our FDM printer recently but not the future."
https://github.com/markniu/PandaPi
RE: Thoughts on 32-Bit and MK3S+
The 12mhz 8 bit board cannot compete with a 100mhz 32bit board. Yes the 8 bit board works but it will not give you the gcode resolution capabilities a 32bit board setup with 0.9 degree steppers can.
I recently upgraded my X & Y steppers to 0.9 degree Moons and I found out later while modding my firmware that you have to reduce the microsteps from 16 to 8 or else it will overload the Einsy board. See the attached screenshot of my firmware and read the Kuo comments.
Also see the photo comparing the same STL printed on Mini vs MK3s+ (3/4 Down the forum page)
https://forum.prusa3d.com/forum/postid/572413/
The more bits the higher your print resolution is, simple as that.
I caved and purchased a MK3 during the recent promotion. I have projects where I needed the larger print bed. It’ll be interesting to run some comparisons like those in your link once my project is complete. Thanks for the link.
Mini+MK3S+XL 5 Tool
RE: Thoughts on 32-Bit and MK3S+
You bet. If you need any help feel free to reach out. I’m currently trying to get my new Palette 3 Pro dialed in with my printer being more accurate, especially the extruder resolution. I had an MMU2s but the board went bad in it three months after use…
RE: Thoughts on 32-Bit and MK3S+
@smibble I've been learning a lot lately about 3D printing. Never heard of the Palette 3 Pro, having looked it up all I can say is wow! Interested in seeing how things work out for you. Please do a follow-up.
Mini+MK3S+XL 5 Tool
RE: Thoughts on 32-Bit and MK3S+
My relation ship with my Palette 3 Pro is of the love hate variety as of now. I feel like I made a breakthrough after a few failed attempts on this print below. There is many variables to consider and my advice to you is wait until your printer is reliable enough for you to be comfortable starting a regular print and walking away.
Prerequisites:
- a printer that is perfectly calibrated with a digital micrometer, well maintained; near perfect slicer settings
- high quality filament recommended
- most importantly, a lot of patience…
You will have to take apart the brand new expensive unit and put a heat sink on the Raspberry Pi 3 compute module’s CPU or else it will lock up on you. The Kisslicer in Canvas is garbage so I went the P2PP route which allows you to still slice in PrusaSlicer. PrusaSlicer is based off Slic3r which is an option in Canvas but I have not tested it yet. The scroll wheel on the P3P gets covered in filament dust which can cause your splice offset to slowly shorten until you get the wrong colour coming out prematurely on large prints like below.
I had to disconnect my OctoPi because the P3P is incompatible.
These were taken at the time of this post:
RE: Thoughts on 32-Bit and MK3S+
One day I'll give my Palette another try. I was hoping that after the MMU2 hell I'd have something more reliable but my initial stabs were disappointing, and support was dismal. I finally got it to print sort of okay but I kept having splice issues, at which point I put the Palette on the back burner. I'm not damning the Palette (nor the MMU2 in fact); it's that either of them appear to need more TLC than I'm willing or can afford to invest.
RE: Thoughts on 32-Bit and MK3S+
@smibble That’s a beautiful print. It’s a shame how finicky these things are considering how much they cost.
Mini+MK3S+XL 5 Tool
RE: Thoughts on 32-Bit and MK3S+
Thank you, that was attempt 3 (third time is a charm). When I figured out that my extruder microstep correction to flow multiplier was throwing the P3P off. (Had mine set at E390 instead of E415 so I could leave it at 1 in the slicer). P3P in connected mode must read your firmware's configuration instead of adjusted EEPROM settings. I’ve had very good success running the P3P in accessory mode. That mode is when the print head pauses at your ping interval for 10 seconds two times and Palette senses the pause on its scroll wheel to measure filament extrusion.
RE: Thoughts on 32-Bit and MK3S+
This got me thinking, with a 32-bit processor would you could create a better MMU experience. Having a processor with more headroom in it should make it a “smarter” controller, and enable better algorithms to catch things like load/unload errors and handle them more gracefully.
Mini+MK3S+XL 5 Tool
RE: Thoughts on 32-Bit and MK3S+
MMU printing will always a challenge but I definitely agree that a 32 bit processor and more sensors would definitely help. I emailed Prusa support asking when their 32bit MK4 is coming out. They said Q2 2023 depending on supply shortages and that there will be an upgrade option (MK3S to MK4).
After spending hundreds of hours with my Mmu2s I found that the weak points are:
-the small Bowden gears which tend to strip the filament
-the control board because I had multiple glitches where the selector didn’t home/locate correctly but the Mmu thought it did. adding heat sinks to the stepper drivers helped a bit.
-if there was a loading issue the printer would stop the extruder after it’s timeout, while I cut out the bad piece of filament, and not restart the extruder after I cleared the Mmu error.
- and the last one which turned my MMU2S into a $300 paperweight was it loading the wrong filament 36 hours into a 72 hour print.