MK2.5 owner - Any reason to upgrade to Core One  

RE: MK2.5 owner - Any reason to upgrade to Core One

My experiences:

I started in 2017
Mk2 - 2.5 - 2.5s  all the upgrades + MMU =  everything but the MMU was great (original MMU took alot of tinkering)

I skipped the Mk3 and got a Mk4 kit -upgrade to the 4s + MMU3 = fantastic machine.   MUCH faster than the 2.5s and generally more reliable including the MMU3.
(however the MMU hates flex - sot he 2.5s is my flex and misc backup machine.  still bangs parts out )

I just recently upgrade the 4s to Core One.  Again a great machine and fun to watch - really fun build.  I have NOT set up the MMU again.  Still debating that...

All that said as background info.

Yes, the Core One or 4s are both great upgrades.

In my opinion about the MMU in general:  it is a fun toy.  MMU3 is a reliable fun toy.  But unless you have a specific part you need multi-color and have the time to tweak the settings for that specific part - filament and colors. AND have a nice payoff for that specific part.   MMU is still just a fun toy.

RE:

I have an older Mk3 that I've updated to almost a Mk3s; repaired and modified a bit, but still running strong.  I just purchased a Core One for the speed and enclosure (easier for high temp plastics).

At this point if I want a "correct" print I still use my Mk3.

The Core One is factory assembled, passed all the calibrations and tests available to me. I've had to do a mod to make it run reliably: static arcing from the belts during long travel or print moves resets it, so had to modify a couple of screws going into the X and Y motors. Simple mod, but the fact it needs it was surprising. Prusa made an attempt to solve this defect but failed: they added a ground wire to the plate the motors sit on, but failed to ensure the screws that hold the motor can pierce the powder coating on said plate.

The printer can be amazingly fast, but with that speed comes a price: detail is lost, and sometimes parts are broken (small features get missed or have serious print issues).  The Bowden system requires relearning old habits and impedes filament handling compared to the Mk3. The UI of the Buddy board is also slow, with a bunch of added checks you must hurdle over to do simple things like start a print or even unload filament - the UI seems to get lost waiting for this or that and requires multiple "OK" steps after selecting a task. IMHO, the UI is a step backwards in time. 

You get two basic print profiles with a 0.4 nozzle: SPEED (questionable quality on fine details); STRUCTURAL (slow prints not much faster than the Mk3, but still has print quality issues, but is a bit better than SPEED profiles).  There is a single 0.8mm nozzle QUALITY profile.

I've had to slow the printer down to Mk3 speeds to get anywhere close to Mk3 quality. See images.

Gray: Mk3, Blue1: Slowed down to 1/2 STRUCTURAL; Blue2: base STRUCTURAL; Blue3: Slowed Acceleration to 1/2 STRUCTURAL.

Beige boxes are STRUCTURAL top, SPEED next to gray box. Gray box is Mk3.

RE:

I can't speak to the comparison, but @tim-24 's images above show much worse quality than I'm seeing from my Core One.  The prints I've done have been very clean with nice looking seams etc., as should be expected.  I would suggest Tim's machine is showing unusually poor quality.

I agree with the critiques mentioned regarding the amount of time it takes to do simple things like loading and unloading filament (why does it need to home, for example?) and starting a print.  The Mk4S I converted from was much quicker to launch.  We've had a pause in firmware updates recently, but I expect the next one will bring welcomed refinement, just like they did for the early Mk4 after launch.

If you are unsure, and generally happy with what you have, there is no reason to rush to upgrade, and I would even recommend holding off.  The next year or two will bring "proper" multi color and multi material options to the market, both inside and outside Prusa.

From purely a speed and quality standpoint, even the budget alternatives are getting very good lately, with positive feedback on the Centauri Carbon and more recently the Qidi Q2.  We just purchased and received the Q2 at my office and the couple of prints I've done have been beautiful, and even cut time off of the same model sliced on my m Core One.  I don't for a second expect the Qidi to be as durable as my Prusa, but it's putting out beautiful parts right out of the gate.  It's good to have options.

-J

RE: MK2.5 owner - Any reason to upgrade to Core One

I came from a MK3, which worked very well, so I wasnt in dire need of a change, but changed to the C1 kit.

+ Very good quality prints

+Very fast, and print quality doesnt change much with at different speed levels.

+Much higher chamber temps than my MK3+DIY enclosure, definitely helps with more difficult materials.

+Robust and compact design

+Remote control of the printer is nice to have for sure

- Fiddly to change filament, the MK3 was so quick at that.

-Heavy to move around, and quite abit more complicated with the belt routing etc

-Maintenance and changing of parts is more time consuming with the integrated core xy design

-both have low maximum nozzle temps, which could be a bit limiting for newer high performance filaments.

So overall very happy so far, the MK3 also did very nice prints, but had some ringing marks etc which my C1 doesnt have, even though it prints much faster.

RE: MK2.5 owner - Any reason to upgrade to Core One

Have to say I came from owning a MK3S+ that started out as a MK3 in 2018 - I was watching the upgrade prices for mk4 and never "bit" due to them being so high compared to the kit price. So when the Core One came out I thought it was a better upgrade after 7 years than disassembling and reassembling my mk3. In my case the prints on the MK3 are starting to look a little "rough" probably due to wear (the printer has over 20,000 hours of printing and I've only replaced the belts, bushings and nozzles/pfte/heat breaks). So in my case generally prints come out mostly better than the MK3. The biggest difference has been in tackling ABS and ASA - I struggled with these due to living in cold and draughty homes, the enclosure on the Core One solves all these issues.

I did buy a Bambu Lab P1S a year ago, in contrast, and like yourself, I found that certain things failed on it that worked perfectly on the MK3. Also find it less good on PETG and non BBL branded filaments whereas I think I only ever had 1 filament that just wouldn't print on the mk3. I'm hanging onto the MK3 for now and will probably give it a good clean soon, but ultimately might end up giving it to my nephews who are just getting to the age they might take an interest in these things.

For a lot of people, obviously there is no good reason to upgrade if your MK3 is doing everything you want it to do but it is really nice to get prints done faster.

RE: MK2.5 owner - Any reason to upgrade to Core One

I'm just a bit surprised by how many easy prints are failing on the Core One. Simple supports that work very well on the Mk3 - like 2mm trees in organic supports - fail and break on the Core One. You'd think Prusa would tune the profiles so supports are effective on their new printers, but that doesn't appear to be the case as I try to print things - looking like 3mm is better for speedy.

Speed kills in going to be my motto for the Core One... lol.

RE: MK2.5 owner - Any reason to upgrade to Core One

Posted by: @tim-24

I'm just a bit surprised by how many easy prints are failing on the Core One. Simple supports that work very well on the Mk3 - like 2mm trees in organic supports - fail and break on the Core One. You'd think Prusa would tune the profiles so supports are effective on their new printers, but that doesn't appear to be the case as I try to print things - looking like 3mm is better for speedy.

Speed kills in going to be my motto for the Core One... lol.

I genuinely think there is something wrong with your machine.  The things you are reporting are not normal on the core one.  I would reach out to Prusa support and make sure they help you troubleshoot until you are getting proper results.  

I do have some noises that show up during heated chamber prints, and I added the nozzle wiping mod just for good measure, but my print quality has been really good from the start.  Just tonight I printed a Bosch router bushing adapter for a friend in ASA, and the finished part looks incredible.  It was a load filament, send the job and walk away process for me.  The core one isn't perfect, and it's not as hands-off as the Mk4(s) was, but it's a very solid printer.  I believe it will continue to improve over time as they always do.

-J

RE:

I'm going to second that. My Core One was a kit, and aside from the feet falling off and a minor issue with my assembly where I inadvertently had the cable for the filament sensor on the left instead of the right of the ptfe tube, causing the y axis to hit it and fail calibration, it's printed perfectly every time for me with no failures.

In contrast when I built my MK3 I had months of trying to get things right because I hadn't correctly tightened up the cable bundle under the extruder that was tipping off prints, and my assembly of the extruder was probably not great either.... Eventually I got both right and the printer printed perfectly.

RE: MK2.5 owner - Any reason to upgrade to Core One

After roughly 2 months of frustration I now have a printer which I can say is superior to the MK4S that spawned it. 

TL;DR 

I bought the MK4 as a kit, upgraded a year later to the MK4S and then a year after that to the Core One. I can say (in my experience) that the MK4 and MK4S never had issues (well no major ones). The Core One on the other hand took about 8 weeks to settle down. The craziest parts of the build? Belt tension for sure, that was much harder than it needed to be. And those feet... I peeled off that awful (anti)-adhesive and glued them on. Eventually I printed new feet; the old feet are somewhere in the county landfill. Then there was the noise from the enclosure resonance that went away when I bought the accelerometer and recalibrated phase stepping. And lastly, all of the grounding issues that took a couple of weeks to fully resolve by grounding the motor housing to prevent the printer from crashing and patching g-code for the nozzle cleaning/Z axis errors. Oh, and the latest firmware updates that allowed turning off that stupid door sensor and nag screen for the top vents.