Tuning the Prusa Core One | Hacker News Reader

Tuning the Prusa Core One

arachnoid.com

59 pointslutusp67 comments

Excellent article. It is very hard to understand a few things about Prusa, lately:

1. The Nextruder looks 5 years behind Bambulab nozzle switching, without to mention the cost of a new nozzle. A clogged nozzle is a non issue in a Bambulab printer, but it causes me a big cost and more work with my MK4 (which has the same extruder as the Core One).

2. How is it possible that these printers still lack at least a cheap webcam?

3. One of the strengths of Prusa should be support. It used to be very good, years ago. Now the issue the OP is reporting about the app that is not able to detect the principal component in the sound of the belt, is an example of a more extended problem, that one can see in many ways, especially in the MK4 / Core One documentation, that is especially lacking.

In general, here the OP is doing the work that Prusa should be doing to provide a better experience, without to mention all the design issues that they are not fixing directly before shipping their printers. I'm also a Bambulab user, and my A1 costed a fraction of my MK4 and it is the printer I always hit because of the zero-issues. It just works.

Now companies may have ups and downs, but there is some problem at Prusa: they are still not understanding what's really happening and where their problems are.

The Buddy3D camera has a firmware update recently, now it can RTSP stream inside your LAN and you can force day/night detection. Also, it saves timelapses to a local microSD. Still not super cheap, but yeah.

1. I think even on bambu people switch extruder so they have swichable nozzles. Atleast thats what i did on my P1S. There is huge aftermarket with these if you need them.

2. Reasoning i heard is that Prusa printers are used a lot by print farms that dont want them for security reasons and that there are aftermarket cams that are going to be a lot better than what they can deliver. Again cam on Bambu P1S is pretty bad so if you like the feature you end up changing it but because the chip in P1S is pretty low powered you end up adding whole different camera system.

3. This is very good point. I guess they were under pressure to release asap and the docs are rushed / in process. The upside is that they have track record of long support for the products.

I am not sure that they are so clueless.

I’ve had P1S for some time. It’s great. I wanted focus on 3D printing not on 3D printer.

But now? Bambu is update away from not being able to print outside their cloud. There is zero openness. They do everything to stop any kinf of reverse engineering or alternative firmwares. Afaik they might just decide tomorrow that they stop support some of the older models and they simply stop printing.

I still ended up messing, modding, tweaking and learning about the Bambu printer anyway.

But i also found a lot of use for 3D printer. So idea of buying 3x times more expensive printer kit that will take me 20h to assemble and then even more time to tweak to print as good as Bambu… is OK? Almost intruging? I will know that with care it will work for a looong time i will know how it works and it will be valuable knowledge.

It seems a lot like linux vs mac. At some point you bite the bullet and never look back. Or you do and go back.

I just buy the built version.

Yeah i am probably cheap OR i have this false idea that i will ubderstand the printer more…

I assembled the mk3s from kit. It was long but at least I have a mental model of where things are, and what to remove first if I needed to exchange parts.

I just finished assembling my Core One.

I definitely understand how the printer works better than if I bought it assembled. It'll definitely save me time troubleshooting/maintaining/repairing it later. But I spent more time building it than I could ever save during teardown/rebuilds.

I bought a kit because I like building stuff, the Core One kit had the same appeal as a Lego model or a model car. If that's not appealing to you, do yourself a favor and buy the completed printer.

If you do get the kit, get a couple of ice cube trays to use to organize fasteners; keeping them organized in the bags Prusa sends was a battle I wasn't interested in fighting.

Thank you! Seems like i am cursed and thus will have to go for a kit.

I think someone says this in every HN post involving CAD, but the reason FreeCAD is "buggy" and Solvespace is small and fast is Solvespace has a fraction of the power. FreeCAD uses the Open Cascade kernel, which can do complex 3d boolean and fillet operations, not having these operations severely limits the geometry you can create, and you will run into walls very quickly using Solvespace, OpenSCAD or anything else with a hand rolled geometry kernel. Even commercial projects use an off the shelf kernel, they're just difficult to write.

This is true, but it's not a reason to put buggy in quotes. FreeCAD is, objectively, full of bugs. Running into bugs all the time also limits what you can create. For hobbyist 3d printing purposes, Solvespace and OpenSCAD can cover the vast majority of simple single-part designs.

I could not imagine trying to design a 3d part without fillets. I use Build123d mostly, and have even gone as far as using the Open Cascade library directly, but if I had to choose between FreeCAD or OpenSCAD/Solvespace I would rather work around FreeCADs jank than give up fillets.

Understandable, there are plugins and workarounds for fillets in OpenSCAD but they're not great.

If you're using Open Cascade through something other than FreeCAD, you may be having a better experience anyway. FreeCAD uses their own fork, which is hundreds of commits behind.

OpenSCAD is verbose, but fillets are just a cylinder subtracted from a rectangular prism.

Fillets in BREP software are so much more complex than this, your statement is a huge oversimplification.

Have you tried BOSL2? [1] Adds a lot to openscad, enough to keep me going at least. Fillets, chamfers, rounding, common parts, anchoring options, and it makes use of parent-child relationships between parts.

Not entirely perfect and some compromises, for example faceting isn't always consistent and hashtag highlighting doesn't seem quite right, but overall still it's good enough for me. The wiki on GitHub is pretty good, and with the source in hand I have had an easy time understanding what it does and tweaking it as needed.

For openscad itself, there are nightly builds with the new geometry engine, which too mostly works for me and is a huge speedup over the older CGAL engine. Renders that took minutes in CGAL now take seconds with the new engine. I like to take faceting through the roof for nicely rounded curves, but that kills CGAL apparently.

[1] https://github.com/BelfrySCAD/BOSL2

I see you still have to add a fudge number to stop the faces intersecting when doing a difference boolean. I'm afraid this is still strictly worse than Build123d or any other DSL than wraps OpenCascade.

I tried build123d with ocp vscode standalone and it seems interesting, but edit->run script->check browser-workflow feels annoyingly slow.

Maybe I'll try blender addon tomorrow.

I've been using it for a while and I honestly don't even check the output until I'm done sometimes. I think it's more important to make good preliminary sketches and have a good idea of what you want to make, checking the output every time you change a dimension isn't that useful.

FreeCAD is a mess. Especially if you're doing things like CAM.

Hard agree.

Alibre CAD has affordable permanent/monthly licenses, I recommend that as the affordable commercial option.

Good timing with this. I had an old maker select v2 from ~2015, and at some point, the SD card got jammed in and ripped the card reader off the PCB, so I just ordered a Core One (preassembled) over the weekend. The CoreXY system (and enclosure) seems more elegant than bed-slinging, but it's evidently more fiddly. Hopefully the enclosure also prevents it from accumulating dust as quickly.

You mentioned you stripped one of the tensioners - does a screw thread into a 3d printed part? Is there a more robust version of the part?

> You mentioned you stripped one of the tensioners - does a screw thread into a 3d printed part?

Sort of. A metal screw is threaded into a square nut that sits inside a 3D printed part. All good unless one gets to the end of the screw's motion range, after which the square nut begins to turn inside the plastic part and strips it.

I have printed spares for the plastic part, also I know better than to trust Prusa's frequency detector applet, so this is not a deal breaker once you understand the system. There are much better ways than Prusa's applet to detect the belt's frequency, some described in the linked article.

Prusa offers free downloads of all the printer's plastic parts: https://www.printables.com/model/1167816-core-one-printable-...

> Is there a more robust version of the part?

The original part is printed using PCCF, very strong, but the embedded square nut is too small to resist worst-case forces.

I didn't realize Paul Lutus had an active blog! I would highly recommend not only reading this post but checking out the author. I read their book Confessions many years ago and it was one of the things that helped push me to look for fulfillment outside of tech.

It looks like he posted this so may see my comment. I just want to say thanks, I appreciate the things you've put out into the world.

The site is filled with cool stuff. I wanted to learn more about optical lenses and found https://arachnoid.com/blender_graphics/index.html to be very useful.

You are most welcome! Because AI has taken over most low-level coding, I think more people will be looking for fulfillment outside tech.

And thank you for your kind words.

Link to my free book "Confessions of a Long-Distance Sailor": https://arachnoid.com/lutusp/sailbook.html

Has anyone made any experience with printer head changes (similar to factory robots exchanging grippers)?

I dont want the print to pause in some gcode function waiting for me to pick &place

The Prusa XL[1] can be configured for 5 toolheads for fast, automatic switching ala factory robots.

[1] https://www.prusa3d.com/en/product/original-prusa-xl-assembl...

There are a large number of "toolchanger" printers out there, include Prusa's XL. They're pretty great: multiple nozzle sizes and types, multi-material and multi-color without a lot of waste, and even the ability to use different tools (like lasers and subtractive manufacturing). In the consumer space the technology is still fairly expensive, and the complexity reduces reliability, but I suspect is going to become more and more of the norm over time.

Most modern printers also support simpler multi-material setups which change the filament in a single tool automatically. Waste is fairly high (because of the need to purge), and speed fairly low (because of the need to purge), but the technology is mature and cheap.

Bambu also has their new 2 head printer the H2D where you can print incompatible materials like PLA and PETG for perfect supports that don't stick to the main print.

Yes, but you could print incompatible materials before just fine. It was just either time-consuming (manual change) or time-consuming and wasteful (AMS-like systems that cut filament)

Two heads lets you keep them completely separate which is good because PETG to PLA tends to jam and you need to purge a LOT to get all the PETG out or it can mix with the PLA causing really weak parts.

Printing multiple materials with an AMS-like system will usually cause print failures. Remnants of the materials will stick in the single print head and mix with the incompatible materials. And manually switching isn't feasible if you're trying to do something like print supports--are you going to swap filament rolls by hand every layer?

I've printed _many_ parts with multi-material using AMS: PLA, PETG, different support materials. Never had a single failure. It's wasteful, but never had issues.

> And manually switching isn't feasible if you're trying to do something like print supports--are you going to swap filament rolls by hand every layer?

No, first because I would use support material just for the interface and if it's curved, then no. Even with X1C's AMS, any IDEX, H2D print time would be hilariously ballooned. I'n saying that dual-nozzle design didn't make it possible, it made it more convenient.

That is curious. I've only tried multimaterial work with an AMS Lite on an A1, but it critically compromised layer bonding due to residue, and it was a reproducible problem.

I have a whole rc plane printed out of PLA-LW and PETG for interface, model used a lot of supports. Still in one piece. My only print issues with x1c:

- I forget which plate was used for petg and which one for pla and mix them up

- Revo nozzles had clogs, solved by switching to diamondback

- Can't pull the very end of the 3rd party spools and either gives me "motor overloaded" or void layers.

I've printed both PETG and PLA just fine (using PETG as a support interface) in the AMS. The key is to turn off the prime tower, and increase the flushing volume between those materials. (I do now have an H2D, and it's definitely an upgrade over having to do that)

What you're looking for a printer with tool changing capabilities such as Prusa XL or DIY like Voron with mods.

What practical reasons are there to choose the Core One over an MK4S or vice-versa? The Core One is slightly more expensive.

The Core One uses a "CoreXY" system where the extruder moves in X and Y directions instead of X and Z, and the bed moves in Z instead of Y. It eliminates issues caused by large prints progressively increasing the mass/momentum on the Y axis, but it requires a more complex system of belts. Also, the Core One only comes in an enclosure, which is good for some materials that need warmer air, but can hinder PLA, which needs cool air.

Generally, it seems like if you just want to reliably print PLA, get a MK4S, but if you want the temp-controlled enclosure or filament versatility, get a Core One.

core one is enclosed and somewhat (20%?) faster

Why does enclosed matter, though?

Apparently there is a filter add-on that might help with printing something smelly?

https://www.prusa3d.com/product/advanced-filtration-for-prus...

Many materials with desirable properties (e.g. temperature resistance, strength) can only be printed in a heated enclosure. ABS and Nylon, for example.

And if you're printing ABS then you need fume extraction because unlike more common materials, ABS fumes are toxic.

It's not strictly necessary for your basic PLA and PETG, but it can help sometimes if the ambient temperature is really low or if the environment is drafty which can cause prints to lift off the bed.

See: https://help.prusa3d.com/filament-material-guide

> Why does enclosed matter, though?

I print mostly ABS filament, and during the winter here in Washington State, I could't make my printer room hot enough to avoid warped prints from my earlier unenclosed printer. This printed completely solved that issue.

Why use ABS instead of ASA? I personally wouldn't be comfortable printing even ASA in an unenclosed printer - ABS would be an absolute no.

> What practical reasons are there to choose the Core One over an MK4S or vice-versa?

The Core One has a Core-XY motion system, meaning the print bed doesn't have to move very fast during printing. This greatly speeds up typical printing.

Also there's the issue of Prusa's open-design philosophy -- you're free to modify the printer's hardware and software.

I've never owned a Bambu Labs printer, so I might not be the best source for a point-by-point comparison.

This article highlights why Bambu has been eating Prusa's lunch the past few years. Imagine spending over $1000 then needing to print parts to get it to work properly.

I swapped my Ender5 for an X1C two years ago, and since then, I have only had to do whatever maintenance the X1C tells me. Using my X1C feels much closer to using my laser paper printer, whereas my Ender5 ended up being a hobby in itself.

this is a nice post on how to maintain and repair a Core One, not things you have to regularly do

kinda irritating that every single thread about a Prusa printer has a dismissive post from someone who went from a janky Ender to a Bambu

> kinda irritating that every single thread about a Prusa printer has a dismissive post from someone who went from a janky Ender to a Bambu

A lot of HN users have bought a Bambu and feel a need to justify their choice after the fact in a way that gels with their outsized need to perform as experts in front of others. This leads to a lot of comments basically just repeating Bambu talking points without having evaluated any alternatives. "The printer for the masses" just becomes received wisdom.

If you know better, just let it wash over you and go do cool stuff.

I'm also sort of wondering if it's a bit of an American thing, where Americans tend to have this odd self-disparaging impulse to call Western-made products crap and point to Asian manufacturers as having figured it out. See e.g. Japanese cars. Perhaps Bambu is perceived as the Toyota of 3D printers or something.

I'm an open source fan boy but my friend is always sending me links to the bambu sales. I don't think she's a self-disparaging american, and we've worked together in FabLabs we've practically used every printer out there so its not for lack of evaluation. She pushes bambu on me because she's sympathetic to what a PITA it is to deal with the majority of printers. Lulzbot is good too but I have to ask myself if my patriotism is worth it to pay 3x as much for a worse product ? Made-In-Colorado is extruded aluminum screwed together with brackets. [0] Made in Shenzhen is welded steel. [1] Also, there is very good reason that Toyota developed its reputation relative to American cars, and it's not Japanophilia.

[0] https://buy.lulzbot.com/products/lulzbot-3d-printer-taz-work...

[1] https://us.store.bambulab.com/products/x1-carbon

The QIDI q1 pro is really good. And pretty amazing for the price/features value

I don't think it has anything to do with a halo around Asian companies. Bambu and Creality are both Chinese. I've used plenty of Prusa, Ender, and Bambu printers, and this is what I've found:

Bambu: break the least. That's it, that's the whole secret to why everyone recommends them. Sure, the print quality is good, and there are some nice QOL things, but they took off because you can hit print and expect to get a print.

Prusa: These are mostly reliable. Not as reliable as Bambu. The Prusa printer I have right now has had two fatal malfunctions over the years I've used it, both of which were due to design flaws Bambu printers don't have. They are making a lot of progress, and I hope they catch back up.

Creality (Ender manufacturer): No one should buy Creality products. They are worthless. Everything from the lowest bargain-bin Ender 3 to the latest K2 Plus will break and might burn the building down.

As someone that went from a janky Ender to a Bambu X1C, I think I can explain the differences. Is your hobby 3d printing? If so a machine that allows you more freedom to tinker and requires more hands on knowledge, but at a slightly lower price makes sense. If you use a 3d printer for your other hobbies, then something more appliance like that just works like the Bambu lines is probably a better fit.

I basically never 3d printed before, because every time I wanted to print I spent more time fiddling with the printer than I spent on my actual hobby. Now I spend almost no time thinking about the printer, and I use it almost daily.

I think both Prusa and Bambu have great printers and target different demographics, Bambu was a better fit for me and my needs, and I think a lot of people fall into the same general class as me. If you want a 3d printing appliance go with a Bambu, if you want to spend time customizing and upgrading and tinkering with a 3d printer go with another brand like Prusa.

> if you want to spend time customizing and upgrading and tinkering with a 3d printer go with another brand like Prusa.

Prusa is the company making reliable, open and therefore repairable/upgradable printers. But reliable is first, and the majority of Prusa printers will not be modified from purchase.

I did not find my Prusa (MK3 upgrade to mk3s and also a new mk3s) to be reliable. It had all sorts of failure modes and eventually I stopped using both of them. I did repair both of them a few times but the extruder design is just really inconvenient. I replaced it with a printer that cost far less - cheap enough that after a few years, if it started to behave poorly, I'd replace it with another cheap printer (after reading reviews to make sure its constraints were consistent with my workflow).

Prusa did some great stuff but the market copied the good stuff and evolved past them.

I bought an MK4 two years ago, it's been printing for 1500+ hours, and I haven't done any tinkering. It's just a workhorse.

Again, you said it yourself: You went from an Ender to a Bambu, and you seem to just assume that a Prusa requires "tinkering".

This was in response to a post about how to setup and calibrate and deal with Prusa Core One issues. The Bambu literally just runs a self calibration on first run, making the need for this sort of process unnecessary.

Maybe it’s not a big deal to do this on first setup, but clearly someone thought it was worth writing a blog post to explain to people.

The article is by a tinkerer. It's not representative of normal use.

The Prusa obviously has a self-calibration, I believe they introduced the idea a few years ago.

Nothing in this blog post is something that has to be done. The normal Core One user experience is to unbox and print a few minutes later.

> ... you seem to just assume that a Prusa requires "tinkering".

I would have said "allows tinkering." Many Prusa buyers expect to be able to improve things by tinkering. It's more a philosophy than a necessity.

There was a time when one's ability to modify a product was a "good thing". When the Apple II came out in 1977, I bought one, and within weeks of tinkering, its designers wouldn't have recognized it. Same idea.

By tinkering I made my Apple II drive a printer, useful for me, but a change the Apple people tried to keep from the non-tinkering public.

It might be genetic, but I've learned to hate closed platforms.

Thanks for making this point, which is very and strangely underrepresented on Hacker News.

I've been made fun of for decades for being a Linux user with slogans like "I want to use my PC, not work on my PC". Guess what, thanks to what I learned and the network it got me I have a nicer occupation than any of them and got to participate in a few projects that changed the world a little. You should seek out experiences that build you, not disparage them.

What makes Prusa so great is that you don't have to "make the 3D printer your hobby", but you definitely can. I can think of few products that balance this so well.

I've just started writing these in the hopes of reaching that 15 yo with potential, not an army of MacBook-wielding TypeScript slingers.

Same boat.

The other thing to note is that they're in stock, folks have had to wait quite a long time to get their core-ones.

I'd love to support prusa or the others instead, but have hardware to ship and can't justify paying more for less reliable and more costly to run printers.

Prusa is great, but it's hard to justify an increased cost to my customers for "greatness".

Core One prebuilt lead time claims to only be 1 week currently, I'll let you know if that's true within a week.

And it has now shipped.

While skimming through this I was thinking "this is a PR disaster", because people are going to see the contrived, extreme ways this guy has fucked up his Prusa printer to illustrate his how-to and think it's representative of the printer that they would receive if they ordered one.

If we're comparing, it would be useful to look at the way these things are done on a Bambu printer.

Z-axis and XY-axis calibration: Designed to be unnecessary. Not possible with stock software. Possible with Orcaslicer on old or custom firmware, in which case the procedure would look similar.

Belt tensioning: Similar, but easier and better designed (no half-baked app involved).

Camera: Bambu also requires an account, I believe. Other than that, it's much better: it comes with the printer, is in color, has a light, runs at a useful framerate, and can take offline timelapses.

I don't think the comparison is positive for Prusa.

> ... I was thinking "this is a PR disaster", because people are going to see the contrived, extreme ways this guy has fucked up his Prusa printer to illustrate his how-to and think it's representative of the printer that they would receive if they ordered one.

Fair comment, but Bambu Labs owners have similar issues on a much less open platform where they can't DIY themselves to a solution.

I'm a bit old-school (and a former NASA engineer). I think being able to fix things yourself is an advantage. Young people might not see the world that way.

But to be frank, I might not be the best Prusa advocate. In the linked article I posted a remedy that involved baling wire, without once asking myself, "Baling wire, really? Won't young people find this hilarious and off-putting?"

There are a number of differences between young people and my generation. One of them is ... we built things.

Learn how to set up and use the new Prusa printer. The article includes troubleshooting tips and example projects.

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