Prusa MK2.5 - Overall Impressions?  

Re: Prusa MK2.5 - Overall Impressions?

Personally, I'm unenthused and considering downgrading back to the 2s.
My take:
https://shop.prusa3d.com/forum/general-discussion-announcements-and-releases-f40/mk2-5-without-the-mk3-problems--t15295-s10.html#p114224

The long and short is, the Mk3 is a regression in some key ways from the 2s. In a lot of ways, it's worth it anyway. All of those ways are left out of the 2.5, so meh.

The 2.5 basically brings a removable bed, temp-compensated leveling sensor, filament sensor, and quiet hotend fan. The bed leads to much greater difficulty leveling, the temp-compensated PINDA doesn't work well at all*1, the filament sensor causes more problems than it solves*2, and the quiet hotend fan eliminates not-enough noise while tanking reliability*3

*1 Temp compensation doesn't work at all - the correction curve, even once calibrated, is basically completely useless. However, the sensor means you can write some custom start code to make sure you always level the bed at a consistent temperature. This isn't a HUGE improvement over the 2s, and it's a big pain, but it is an improvement.

*2 I wanted the filament sensor more than anything else to handle automatic runout detection. In a few months of using the 2.5, I tested this successfully once or twice, then used it in anger on two many-hour prints to use up 400 grams left on a spool, for a 600 gram print (didn't want to use one spool per print and have a whole bunch of leftover partials). It failed every time I used it on an actual print, costing me about $20 and days of time. Jam detection has also failed me multiple times, failing to detect a jam when a print could have been recovered. Worse, enabling the sensor results in false positives of both runouts and jams, stopping prints needlessly mid-way. This might be fixed by FW 3.5.x, but it was badly exacerbated in 3.4.x so much so I had to downgrade to 3.3 again.

*3 The noctua moves way less air than the old loud fan. On the 2.5, it makes a noticeable difference in overall noise, but because the motors and cooling fan are still super loud, it's not the difference between "annoying in the living room" and "quiet enough you don't notice it," so it's sort of who cares. The disadvantage is, because it moves a lot less air, I get REGULAR heat creep jams, especially when trying to print enclosed. Enclosed ABS printing is literally no longer an option. HUGE regression in performance there.

Basically, the 2.5 upgrade is a bust, and its shortcomings are bad enough that I probably wouldn't buy a 3 given the option, either. I'll probably go get a Palette 2 for multimaterial (on any printer in my fleet!), and maybe build my own workhorse with less archaic electronics. Or just mod-upgrade a CR10 or something.

Re: Prusa MK2.5 - Overall Impressions?

I have found the upgrade to MK2.5 worthwhile. The biggest advantage for me is the removable bed since it makes removing parts much easier. I keep one side for PLA and the other for PETG or other filement where a glue stick might be useful.

On my MK2S I always had to adjust the live Z setting between PLA and PETG. I no longer have to do that.

I did have a couple of filament jams after upgrading. But, none since upgrading to the R3 extruder. Although some of that might be related to lower temps in the house. Probably would have been better using the old fan. It is quiet until the parts fan turns on.

Filament sensor has mostly worked except for having to turn it off for black PETG. But, I am usually watching when the filament running out.

David

Re: Prusa MK2.5 - Overall Impressions?

The biggest advantage for me is the removable bed since it makes removing parts much easier.

This is sort of neither here nor there for the discussion at hand, but might be useful. The real benefit of the removeable bed is in being able to un-stick prints fast. If you have the right print removal tool, this isn't a problem at all except for the absolute largest prints, and even then, is pretty workable.

My print removal tool is a 2" putty knife sharpened on a bench grinder (or belt sander, or manually) on only one side at about a 30 degree angle. The corners have been rounded so they don't catch. It's sharp enough that I often use it for deburring too, to give you an idea. Using this, I've never had trouble getting a print off the bed, and i usually find it easier even on the 2.5 bed vs taking the sheet off - now I only remove the sheet for such huge prints that I'd have to fight it otherwise.

Re: Prusa MK2.5 - Overall Impressions?

As one who owns 3 other 3D printers, I can say the MK2.5 is the best of the bunch, finally. This wasn't always the case. A removable flexbed is now the standard I use on all printers, with the exception of a Anycubic that uses a glass base. Personally I don't use PEI as I think Buildtak is so much better. I haven't used a spatula in years. Yes the Buildtak does wear out over maybe a 100 prints, but its well worth it. PEI is too temperamental in my book.

The second BIG improvement is the temp compensated PRINDA sensor. How that old one on the MK2 was allowed to be used on a commercial product, I do not know. It was not repeatable AT ALL. Then there is the filament sensor, and the Bondteck gears. Both VERY big upgrades.

In my opinion, the MK2 was average at best, and very frustrating at worst. the MK2.5 is just so much more refined.

But of course, its not perfect. It could be enclosed with a filter system, and could have a bigger build area. Plus a dual extruder isn't a bad idea, even with the multi material upgrade. I ordered MMU 2.0 but probably won't see it for years. Make one extruder for PLA and another all-metal with a ruby nozzle. I think both are helpful. I use ruby nozzle which works great but brass is better in some situations.

Overall, I wouldn't hesitate to upgrade, one bit. In fact without the upgrade the MK2 is not even acceptable in my book. And don't get me started on MMU V1.0 which MAKE magazine in 2017 named one of its best. I have definitely lost any respect for MAKE magazine.

Re: Prusa MK2.5 - Overall Impressions?

Personally, I'm unenthused and considering downgrading back to the 2s.

*3 The noctua moves way less air than the old loud fan. On the 2.5, it makes a noticeable difference in overall noise, but because the motors and cooling fan are still super loud, it's not the difference between "annoying in the living room" and "quiet enough you don't notice it," so it's sort of who cares. The disadvantage is, because it moves a lot less air, I get REGULAR heat creep jams, especially when trying to print enclosed. Enclosed ABS printing is literally no longer an option. HUGE regression in performance there.

Uh huh. I would say you under-characterized the quiet. It is INDEED a lot quieter and this is awesome! Until you add an MMU then there's more noise from unused stepper motors just being powered than there is from the fans altogether.
Anyway, the point was right - since it stops PRINTING, it stops being useful. I have many quiet rocks and spatulas but none of them print stuff. Neither did my Mk3 until I added fans and heatsinks.

Re: Prusa MK2.5 - Overall Impressions?

I'm currently building/upgrading my MK2S to the MK2.5.

Question - What does everyone think about the upgrade? Worthwhile? I haven't seen much feedback from the users. Curious about speed, consistency, quality, easy of use. https://downloader.vip/the-pirate-bay/ PutLocker https://appsync.biz/123movies/

Are there any features found on the MK3 that you really wish you had on the MK2.5?

Thank you
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Re: Prusa MK2.5 - Overall Impressions?

Personally, I'm unenthused and considering downgrading back to the 2s.
My take:
https://shop.prusa3d.com/forum/general-discussion-announcements-and-releases-f40/mk2-5-without-the-mk3-problems--t15295-s10.html#p114224

The long and short is, the Mk3 is a regression in some key ways from the 2s. In a lot of ways, it's worth it anyway. All of those ways are left out of the 2.5, so meh.

The 2.5 basically brings a removable bed, temp-compensated leveling sensor, filament sensor, and quiet hotend fan. The bed leads to much greater difficulty leveling, the temp-compensated PINDA doesn't work well at all*1, the filament sensor causes more problems than it solves*2, and the quiet hotend fan eliminates not-enough noise while tanking reliability*3

*1 Temp compensation doesn't work at all - the correction curve, even once calibrated, is basically completely useless. However, the sensor means you can write some custom start code to make sure you always level the bed at a consistent temperature. This isn't a HUGE improvement over the 2s, and it's a big pain, but it is an improvement.

*2 I wanted the filament sensor more than anything else to handle automatic runout detection. In a few months of using the 2.5, I tested this successfully once or twice, then used it in anger on two many-hour prints to use up 400 grams left on a spool, for a 600 gram print (didn't want to use one spool per print and have a whole bunch of leftover partials). It failed every time I used it on an actual print, costing me about $20 and days of time. Jam detection has also failed me multiple times, failing to detect a jam when a print could have been recovered. Worse, enabling the sensor results in false positives of both runouts and jams, stopping prints needlessly mid-way. This might be fixed by FW 3.5.x, but it was badly exacerbated in 3.4.x so much so I had to downgrade to 3.3 again.

*3 The noctua moves way less air than the old loud fan. On the 2.5, it makes a noticeable difference in overall noise, but because the motors and cooling fan are still super loud, it's not the difference between "annoying in the living room" and "quiet enough you don't notice it," so it's sort of who cares. The disadvantage is, because it moves a lot less air, I get REGULAR heat creep jams, especially when trying to print enclosed. Enclosed ABS printing is literally no longer an option. HUGE regression in performance there.

Basically, the 2.5 upgrade is a bust, and its shortcomings are bad enough that I probably wouldn't buy a 3 given the option, either. I'll probably go get a Palette 2 for multimaterial (on any printer in my fleet!), and maybe build my own workhorse with less archaic electronics. Or just mod-upgrade a CR10 or something.

It does not have JAM detection, no where does it state so. the sensor could be replaced by a more reliable mechanical switch most likely. Outside of false positives on black, the run out has worked 100% of the time for me. also it would be impossible not to hear the annoying beep unless it was outside in another location.... or your hard of hearing.

The bed is nice.... works fine and i love it. plus you have TWO beds now... it's a whole new one so if it dies you still do have a replacement at least.

The fan sucks yes, but the hotend design for it is worse, fix it and it isn't so bad or uses a duct/extension for the 20mm thick version. Your point about jams in an enclosure is valid but f you're printing in an enclosure ANyWAY you need to use a ducted cooling solution with a hose to pull in outside air with a return to be truly effective. however with a better design and the 20mm version you avoid that for most scenarios. however you risk the PS and electronics failing being in an enclosure at those temperatures.

if your cooling fan is as loud as the 30mm stock V6 fan, it's broke. they're at least 10db quieter.

However, one thing left out is the surface quality. the bondtech gears are also new and they are garbage. if you print with mk2.5 and 3 for months then switch to a CR-10 or any other machine (like mine with a titan aero) you'll have a WTF moment.... the quality out of CR10 and enter 3 for example is superior to current generation MK2.5-3 machines... by far. no it's not the trinamics... i have a duet on another machine and it's quality is top notch. however regardless the reliability is actually near the best you c an get vs machine like the Cr10 so you have to pick your battles. if they actually fixed it instead of saying "all printers do it" and just never talk about it again... that's a problem. i've lost some respect for prusa on that. just wait, the MK4 will come out with it fixed. if not that would be a disappointment.

Re: Prusa MK2.5 - Overall Impressions?

I'm currently building/upgrading my MK2S to the MK2.5.

Question - What does everyone think about the upgrade? Worthwhile? I haven't seen much feedback from the users. Curious about speed, consistency, quality, easy of use. http://movieseriesworld.com/

Are there any features found on the MK3 that you really wish you had on the MK2.5?

Thank you so much
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Re: Prusa MK2.5 - Overall Impressions?

Regretting the upgrade more and more to be honest. I've never had adhesion problems before, but getting things to stick on this metal (gold-ish looking) plate is horrible. I've started using painters tape to have a chance, and even that is spotty. Extruding is more unreliable, and now the bed refuses to heat.

I like the concept of a removeable surface, but I'm not sure it's worth the pain. I had a 100% reliable mk2s and the 2.5 cost me lots of frustration and plastic.

Re: Prusa MK2.5 - Overall Impressions?

I wish i could have just upgraded to the removable plate. As mentioned in previous posts here, the new extruder parts add more problems than they solve. If your MK2S works like a charm: stick to it! (imho)

Re: Prusa MK2.5 - Overall Impressions?

1. No regrets on the update to MK2.5. Removable build plate is a dream, don't want to go back. I've replaced PEI sheet on my MK2/MK2S twice. That's the most time wasting and chemical process. Any sticking/non-sticking issues are the same for MK2 and MK2.5/MK3 PEI.

2. The new reworked R3 extruder is working fine for me. No issues. Even the print quality is the same. I have my old benchys and don't see any difference between old MK2 benchy and new MK2.5 benchy on my machine.

3. New PINDA with thermal sensor fixed any z-adjust roulette issues.

This is my summary after 6 month upgrade to MK2.5.

Re: Prusa MK2.5 - Overall Impressions?

I'm not really sure how to feel about the 2.5 upgrade. It feels a little like a code branch that leads to a dead end of sorts. I really do wish I'd just gone ahead and bought the mk3 upgrade instead, at least to stay in the mainstream. I now have two Prusa printers because the wife gifted me the mk3 for Christmas. It's February now and I finally received it a second time because I had to send it back for repairs. My experience with it initially left me thinking maybe Prusa had lost their minds and I didn't trust it at all. My mk2s was just always spot on, after all.

Even with those misgivings, after I sent my mk3 back for "repair" (which honestly I wish they'd have just sent me a whole new printer and not made me keep one that was defective - even though it appears the DID fix it and I am happy with it now -- but it's the principle of the matter ) I bought and received the mk2.5 upgrade. In a big way I am glad I did that even though now I'm stuck there, basically. The reason is that I always bought assembled printers (thus the warranty service). It did me a lot of good to tear my mk2s apart for the upgrade because I had never taken any of it apart prior to that. So all you who built yours from kits already know what I'm talking about I think. It helps in understanding how the machine works to see it go together... especially around how the new bondtech gears work.

My take is that if there were no option to go to the mk3 instead, the 2.5 upgrade is entirely worthwhile. I'm assuming with the 2.5s upgrade the filament sensor issues are gone, so I won't pick on that. I think we've all had false positives there and I look forward to that little upgrade maybe. Or just turning that piece off, which is totally an option.

BUT THE REMOVABLE PRINT SURFACE IS HUGE. YYYUUUGGGEEE! When I grew up and got a real job I decided I would treat myself as my own contractor. So I decided what my hourly rate would be and used that to start evaluating the real cost of my time with things I used to do because I didn't have the money to pay someone else to do it. Think about replacing PEI sheets on the old mk2s or even the new steel sheets. That is not a rewarding job. It isn't fun. It brings no pleasure. A whole new DOUBLE SIDED smooth steel sheet from Prusa is less than $30. Why in the round world would you even worry about the occasional PEI sheet getting fouled up? The answer might be that you shouldn't. Just keep a couple extras on hand. Swapping around for that next print is an incredible ability, and if something gets crapped up, you can flip it right over and keep going while you submit an order to replace it. I wouldn't ever throw them away I guess... but I wouldn't have to stop printing while I pull things apart, stick it in the freezer and torture myself replacing the dang thing. In that context, fixing them with new PEI doesn't seem like such a bad thing. 🙂

I wasn't really worried about the noise of the machine so that wasn't a big deal to me. I'd long ago dealt with it by sticking it in an enclosure in a remote room of the house. That said, the mk3 is significantly quieter than the mk2.5. But the part cooling fan on the mk3 is a detractor because it is really a lot louder than the rest of the printer, it seems. That said, the 2.5 in my opinion is a lot quieter than the 2s. That old fan was loud. I used the R3 parts, and haven't had any issues with over heating or jams. Maybe I just came late enough to the game to just enjoy the new model?

Anyway, I couldn't resist throwing in my 2 cents. 🙂

RE: Prusa MK2.5 - Overall Impressions?

Do you have a Prusa 2.5, with a Duet 3 card?