After 1 Week with the Core One ... was this a good idea?
I've had a Core One for a week - so far there have been good bits and bits that could be better ...
To put things in context I'm coming from a 6 year old Mini (the first iteration, not the Mini+) - so I was expecting to be impressed.
Pros
1) The improvement in the quality of printing is noticeable - less surface blemishes - layers aren't as pronounced
2) The print speed is phenomenal (compared with the Mini)
3) Larger print size
4) Ability to print more 'exotic' materials
5) Prusa Connect (& the Buddy camera) makes setup / monitoring a 'breeze'
Cons
1) Whilst the increase in print speed great, there's a lot more 'faffing' about before the actual printing starts. The initialisation seems to take forever compared to my Mini (it's like I've bought a Ferrari that needs an MOT before every use - fine for a 1000 mile road trip but if I just want to pop to the shops it's quicker on a push bike 😆).
2) I have to pick filament (PETG) off the hot end after every print and then clean it with a brush (the mini required hardly any hot end cleaning unless a print failed).
3) More regular print plate cleaning (with dishwashing liquid - 'dish soap' if you're 'west of the pond') - every 3 - 5 prints or so or the first layer lifts
4) Because of (2) & (3) above I have to 'baby sit' the start of every print ... about 15mins thanks to (1) above
5) The display touch panel doesn't work for the 'low down' buttons ('CONTINUE' / 'YES' / 'NO' answers to prompts) - I have to use the selector knob for these
6) The print plates are thinner than the Mini ones - don't feel as substantial, much more of a 'consumable' - My Mini ones are still 'as new' after 6+ years
I deliberated for weeks over whether to get the kit or the pre-assembled version - I assembled my Mini from a kit so I was 'up' for building the Core One myself. The deciding factor was the issue with the printhead banging on the X/Y gantry which it seems like a lot of people (mainly those who opted for the kit) have suffered from. As it turned out, my pre-assembled version only 'head bangs' 4 times on each axis so I got off lightly (although the decision to go for pre-assembled cost me as much as my Mini). This method of establishing the printhead position seems 'low-tech' and detracts from Prusa's reputation for quality (IMHO).
I 'bow' to Prusa's expert knowledge as to the necessity for all this initialisation and the requirement for some of it is obvious (bed level probing etc.). I was impressed by their attention to detail with the ~8 min 'heat absorption' phase in the pre-print initialisation which I believe is to accommodate the enclosure heat retention and allows the XY gantry to expand and settle down for accurate positioning, but why does this 'heat absorption' phase happen after the 'head banging' checks (which seem to happen for every operation - even a filament change)? I thought these 'head banging' checks were required for 'accurate' printhead positioning, accommodating any expansion of the gantry.
I've noticed I do get VFAs on the X axis (more noticeable with shiny filament) but I can live with them - I think I can reduce them if I angle the print - object size permitting (I haven't noticed any on cylindrical/arc'ed shapes), I don't want to mess with the belt tensioning and worsen the 'head banging'.
All in all I think the 'Pros' outweigh the 'cons' (hopefully some/most of these will be addressed by firmware upgrades - it's still 'early days' yet) and I'm 'blown away' by the speed of the Core One (...for longer prints) and the quality.
RE: After 1 Week with the Core One ... was this a good idea?
I think you have a pretty accurate assessment to be fair. I also feel I have to babysit the printer for a while (whereas my H2D lives outside in the outbuilding, where I send a remote job and don't even have to check until the print has ended), and yes, I also found I need to clean the nozzle after each and veery PETG print (although I print mainly PLA where there is no such issue thankfully).
RE: After 1 Week with the Core One ... was this a good idea?
The cleaning of the nozzle with PETG also happens to me. Some prints fail after a few layers cause the blob suddenly comes of and blocks the axis to cause an shift for the following print layers...that anoying.
RE: After 1 Week with the Core One ... was this a good idea?
BTW, if it makes any difference, Im using a 0.4 ObXidion nozzle (non HF) with Prusament PETG......for now, I'm reverting back to PLA unless I actually have a need for any other material!
RE: After 1 Week with the Core One ... was this a good idea?
for now, I'm reverting back to PLA unless I actually have a need for any other material!
That's not really in line with the promise of the fully enclosed Core One. 🙁
As the product description in Prusa's shop states,
The enclosed chamber, capable of reaching up to 55 °C, features active temperature control for high-quality printing across a wide range of materials from PLA and PETG (even with the door closed) to more demanding materials like ASA, PC, or Nylon.
RE: After 1 Week with the Core One ... was this a good idea?
My first print on the satin sheet with the last bit of my Prusament PETG went OK but the next one with Sunlu PETG (using prusa slicer parameters for Sunlu) failed on the first layer. I cleaned the sheet with washing up liquid, then, based on my Mini settings, reduced the nozzle temp to 240, set the bed temp to 90 and selected stealth mode (to slow things down a bit). Since then I’ve had no failed prints but, as I said in the original post, I have to pick a thin film of PETG off the hot end in order to get it past the nozzle cleaning on the next print.
(I’m waiting for some galaxy black prusament PETG to see if it makes any difference)
I’m still using the standard HF o.4 brass nozzle that came with the Core One (I’ve got the 0.4 non HF obxidian - to play with some PC blend - but I’ve not installed it yet)
RE: After 1 Week with the Core One ... was this a good idea?
I was expecting much 'cleaner' prints with next to no warping with an enclosed printer (the Core One is my first true enclosed unit), but to be fair in actuality my results are pretty much on par with the non-enclosed MK4s I replaced it with. As I said, Im primarily a PLA user, and ventured into PETG with the MK4 with its auto bed levelling, and now the Core One, and, honestly, I'm a bit OCD with my nozzle! I like it to be clean at all times, and I hate seeing any PETG reminents being stuck to it after a single print - even worse when a small blob makes its way onto the actual model, leaving a zit or stringing. Because of that, and the VFA's, I've only used PETG for actual functional parts where I don't care too much about quality - desiccant buckets for my drying station etc.
In comparison, I have a competing enclosed unit that came with a textured sheet by default, and that's never given me any issues no matter what I throw at it.....so far anyways!
I'm sure Prusa will continue to refine and develop the Core One further with more updates, and I can't wait for it to give me the same 'send a print and walk away' feeling the MK4s used to give me, but at the moment I just don't feel it's at that point yet......
for now, I'm reverting back to PLA unless I actually have a need for any other material!
That's not really in line with the promise of the fully enclosed Core One. 🙁
As the product description in Prusa's shop states,The enclosed chamber, capable of reaching up to 55 °C, features active temperature control for high-quality printing across a wide range of materials from PLA and PETG (even with the door closed) to more demanding materials like ASA, PC, or Nylon.
RE: After 1 Week with the Core One ... was this a good idea?
Hmm for me, I tend to not trust the pre-defined profiles for non-Prusa filaments. For example, for eSun PLA, i find the nozzle temperature too hot (250C->230C), and for a few other PETG filaments, I find the bed not hot enough (usually bump it up to 80C depending on the brand's recommendations) and the nozzle too hot.
For context, I use the Obxidian 0.4mm HF nozzle and use both speed and structural print profiles.
Usually I print a benchy for each new brand and type of filament I get to get an idea of the filament settings for that brand and filament.
I'm also not an expert by any means and may not be as attentive/caring to all the details as others are, so that can play a part too.
Again, so much annoyance with Prusa. Why did i go down the MK4 path? wish I hadn't.
I received the MK4 to CoreOne upgrade kit. It's got a gazillion parts and it's going to take so long to upgrade. I don't understand why this is so complicated, but maybe I will while putting the damned thing together. Based on the basic MK4 performance, I'm guessing the Core One upgrade will not surpass the Bambu Carbon printer that shares its' table and is half the cost of the stupid Prusa. But I bought the damned Core One upgrade kit because I was already invested in the MK4 and I need the damned printer to reliably print parts which, to date, it has been incapable of doing. So, yes, I doubled-down in the hopes that "more kit" would help my parts. I will report. So far, as you can probably tell, I'm thoroughly unimpressed with the MK4. Bambu has been way better, way more reliable, so far. I also like to say "damned", apparently.
RE: After 1 Week with the Core One ... was this a good idea?
Regarding the PETG nozzle buildup problem, I found some custom printer gcode (somewhere in this forum) that allows me to reduce the extrusion multiplier to .96 on the first layer and then transition to .99 for the remainder of the print. I'm using VoxelPETG+. It has always been the large bottom layers that kick off the buildup and then it gets worse unless I have enough gyroid infill which tends to allow the nozzle to clean back up. If a model has a large base of 4-5 layers and then very little infill, the build up will continue until it drops off. This modifier seems to help a lot. I ran a 5 hour print today in PETG with no nozzle build up. I chalk this up to filament tuning, and so far I see no evidence of under extrusion anywhere to accompany the significantly reduction of the typical PETG issues. I almost exclusively print PETG, and it has acted about the same between my Mk4S and then my converted Core One. No surprise because it's the exact same extruder.
It might be worth looking into the extrusion multiplier gcode. I can share it here once I'm back to my PC. I don't need to run that gcode on any other materials.
-J
RE: After 1 Week with the Core One ... was this a good idea?
Very good summary. A couple of points:
1. Why PETG? This printer can print ASA and ABS very well.
2. To reduce the head banging, change the start gcode in prusa slicer from 'G28' to 'G28 I'.
3. The absorption ('soaking') delay of about 10 minutes is short compared other printers so it's a plus, and the printer gets to a high chamber temperature due to its small volume (also a plus)
4. Any cheap web cam performs better than this 0.1 fps camera (when using Prusa Connect).
Overall the printer design has many corner cutting (E.g. machine screws into plastic, think sheet threads with no inserts, a single Z driver with no bed leveling, no linear rails for the Y axis, no X/Y end limit sensors, and more) but it produces good prints in a reasonable speed, at least when new.
RE: After 1 Week with the Core One ... was this a good idea?
Curious why you're questioning PETG. To me, it seems the perfect material: non-toxic, strong, builds with minimal fuss, as opposed to all the ABS/ASA overhead/special-processing considerations. Then you have PETG-CF, which is fantastic and in my view, better than ABS. Please shoot holes in this, I'd love to learn.
RE: After 1 Week with the Core One ... was this a good idea?
Also, what does "G28 I" g-code do? Yes, I could google, but for the sake of the thread, would be great to have the answers here.
RE: After 1 Week with the Core One ... was this a good idea?
Curious why you're questioning PETG. To me, it seems the perfect material: non-toxic, strong, builds with minimal fuss, as opposed to all the ABS/ASA overhead/special-processing considerations. Then you have PETG-CF, which is fantastic and in my view, better than ABS. Please shoot holes in this, I'd love to learP
PETG tends to create 'bugger' in the print nozzle. It's popular with open printers as a higher temp PLA that doesn't wraps but with a real closed printer such as the CORE One, ASA and better choices in my opinion.
I wouldn't be surprised if PETG is popular here just because people got used to it on their open Prusa printers. You will find it to be much less likely in open closed printers communities such as the VORON 2.
RE:
Also, what does "G28 I" g-code do? Yes, I could google, but for the sake of the thread, would be great to have the answers here.
Prusa added to Marlin an X/Y homing refinement algorithm that causes the CORE One head banging issues affects many users. 'G28 I' tells the printer to use instead a more standard X/Y homing algorithm, without the Prusa's defective part.
RE: After 1 Week with the Core One ... was this a good idea?
I meant 'booger', those small pieces of PETG that tend to stick to the nozzle.
PETG tends to create 'bugger' in the print nozzle....
RE: After 1 Week with the Core One ... was this a good idea?
@ zapta to answer some of your points (please note, there is no antagonism intended, I'm merely answering your questions - don't take it the wrong way)
1. Why PETG? This printer can print ASA and ABS very well.
As I said, I'm coming from a Mini - my (small amount of) 'experience' is with PLA & PETG so I'm starting with these (PETG being the more 'useful' for functional prints)
Also my current (small) project has a requirement to be 'food safe' (ABS definitely isn't and the 'jury's out' on ASA)
2. To reduce the head banging, change the start gcode in prusa slicer from 'G28' to 'G28 I'.
'Head banging' was a major issue when I was making the decision which way to go (kit or pre-assembled) and the 'G28 / I' mod wasn't available then (or, at least, I wasn't aware of it). As I said, 'Head banging' isn't that bad for me (although I don't think it presents a good image for Prusa)
4. Any cheap web cam performs better than this 0.1 fps camera (when using Prusa Connect).
I'd made an enclosure for my Mini - no real need but I did it anyway - and I included a Pi zero webcam in the enclosure. I have to run a script in a terminal window to take a picture, then explicitly delete it for housekeeping (all of which could only be done while on my home WiFi network), now admittedly this may not be the most 'advanced' script but I 'got by' with it - the Buddy camera is a considerable improvement although evidently there are more advanced solutions.
Regarding the 'heat absorption' - I did say I was impressed but my question was why does it happen after the 'head banging'? If 'heat absorption' is supposed to allow the Gantry to expand and settle then surely the time for establishing accurate printhead position is *after* the gantry geometry has adjusted.
RE: After 1 Week with the Core One ... was this a good idea?
Regarding the 'heat absorption' - I did say I was impressed but my question was why does it happen after the 'head banging'? If 'heat absorption' is supposed to allow the Gantry to expand and settle then surely the time for establishing accurate printhead position is *after* the gantry geometry has adjusted.
The head banging isn't about a perfect position in relation to the XY-frame. It's so extensive to be extremely accurate, if a power outage happens.
The order of doing things doesn't matter, since you'd repeat it exactly the same, coming from a cold printer, but it's better to make sure the mechanical parts are working correctly, before warming the whole printer to then fail the calibration.
RE: After 1 Week with the Core One ... was this a good idea?
While building my conversion kit, I took great care to square the gantry so I've not had any excessive bumping even from the start. Even so, yesterday I took a closer look at the extruder cover piece while sliding the extruder to the right hand stop. I noticed that it was resting flexed out a bit from flush, and was making light contact just before the extruder frame hit the side. I ended up printing out a .2mm shim in ASA and gluing it to the back surface where the two cover screws mount to the extruder. After the glue cured, I sanded a bevel on the mounting surface of the cover and reinstalled. The slight bevel flattened out the interface perfectly, and now the extruder bumps directly into the RH as intended with no contact in the cover at all.
It's important to note that I never got over 15 seconds of bumping before, but so far this small change has reduced it to a consistent (normal) routine of bumping, with no extra. It was an easy fix, and realistically could have been done by modifying the stock cover piece to add a .2mm ridge across the rear surface of where that cover mounts up.
-J
RE: After 1 Week with the Core One ... was this a good idea?
I received the MK4 to CoreOne upgrade kit. It's got a gazillion parts and it's going to take so long to upgrade. I don't understand why this is so complicated, but maybe I will while putting the damned thing together. Based on the basic MK4 performance, I'm guessing the Core One upgrade will not surpass the Bambu Carbon printer that shares its' table and is half the cost of the stupid Prusa. But I bought the damned Core One upgrade kit because I was already invested in the MK4 and I need the damned printer to reliably print parts which, to date, it has been incapable of doing. So, yes, I doubled-down in the hopes that "more kit" would help my parts. I will report. So far, as you can probably tell, I'm thoroughly unimpressed with the MK4. Bambu has been way better, way more reliable, so far. I also like to say "damned", apparently.
So you are disappointed with your MK4 and don't particularly enjoy kit-building. And you are satisfied with your Bambu printer and don't seem concerned about their lock-in strategy.
Remind me again, why did you buy the Prusa upgrade kit, rather than spend the exact same amount of money on a P1S? 🙄