Two Puppet Thumbs Down on the "Original Prusa i3 MK2"

[jhcs_mike]

I rarely post negative things because the last thing we all need is more negativity in this world. However, that being said… DON’T INVEST IN AN “ORIGINAL PRUSA i3 MK2”! … Look, I get it… the thing has got a ton of positive reviews… I get it that, even here (3DHubs) it ranks/ lists at the top of the “Budget” category… I get it that it does take a lot of the hassle out of 3D printing… UNTIL it ceases to be reliable in every sense…

I work at the Jim Henson’s Creature Shop. We are currently in pre-production on all the fun stuff for the upcoming series “The Dark Crystal: Age of Resistance”… & that’s all I can say about that. I am one of the 3D guys here & am honored to be working with legendary guys on a bunch of the Mech stuff (Mechanicals/ Animatronics) for a ton of the puppets for the upcoming series. Unfortunately I came onto the project after decisions had been made about the purchase of 3D printing gear, Including 2 “Original Prusa i3 MK2” machines.
I have been in Industrial Design since the late 90’s & involved with (What used to be referred to only as “Rapid Prototyping”) 3D printing since the early 2000’s, when everything was sent out to be printed on big expensive SLA machines. Then in late 2006 3D printing became even more of a staple for me when I started working in TV, Film, Children’s Toys & Product design for several companies & studios out here in L.A.

So, needless to say I have been doing this a while & have worked with many 3D printers & every type of 3D print technology. Currently between myself & with one of my other industry partners (who has his own shop) I have 14 3D Printers I own, or we purchased together. Those 14 machines range from FDM, SLA, and DLP types from 8 different manufacturers…
I hate to say this, but I have NEVER had as many problems with any of those machines as I have with these two Prusa machines…

Now, let me backtrack a bit on my words and say this: when these machines run, you can achieve excellent prints. If you are a hobbyist who will be printing one-offs for the most part of your designs & makes, this may be a machine for you. For the print volume it does come in at a good price point.
However c’mon with the 3D printed parts made by the 3D printer already! Aren’t we passed this gimmick?! ALL 3D Printers now should be ALL Metal construction… Period. In fact I just recommended someone just getting into 3d printing the other day, look into an MP select Mini. Literally less than $220 for a completely assembled, all-metal frame, solid little machine. These Prusa things even resort to zip-ties to hold guide-rods & linear bearings on for cryin’ out loud! What is the point of sacrificing precision on a precision machine?..

The nitty-gritty of our two machines:

Automatic Mesh Bed Leveling constantly failing… I have had “sensor triggered too high” errors. Have had the sensor not triggering at all resulting in the nozzle crashing down into the bed, during Z calibration & during the Mesh Leveling routine right prior to a print RIGHT AFTER calibrating the Z! Have had to re-calibrate the Z from one day to the next when the machine would not store it’s Z calibration after being turned off. Have had to painstakingly adjust the proximity sensor little-by-little till the errors went away & got a successful print, only to come back the next day & have sensor errors & all the other problems again. ON BOTH MACHINES.

Little Nugget… So One Day… Yeah, I think pictures tell a thousand words on this one. Resulting in having to tear apart/ disassemble the entire hotend/extruder/x-axis assembly, print new parts, soak the nugget in acetone to see if anything was salvageable, etc, etc… For the Record, this is the first time I have EVER seen something like this happen to this extent. I mean weird ooze here and there from something loose or the nozzle catching on a part of the print, sure. But this?.. Thermistor was shot by the way… So how did the machine not error out with “Thermal Runaway”?.. interesting…

The Nugget Strikes Back … Yeeeeaaaaaahhh… it happened again. Same Machine. Complete re-build with a new parts/hotend. … interesting…

Firmware… When I met these machines both still had the 3.0.10 (Feb 2017) Firmware. I did my duty & upgraded both with the July 2017 3.0.12 version. While one is running fine *When it Runs* with the latest, I had to re-flash back to the 3.0.10 on the other to get it to perform reasonably stable *when it runs reasonably*

Other Bits… These were optioned with the upgraded assembly U-bolts to hold the linear bearings that live on the underside of the bed. (Thank the maker, because those standard are again, apparently only held on with zip-ties… wtf people?) After relatively low hours for the life of a 3D printer, the bearings under the bed on both machines began to go bad. Now, if you’ve seen the inside of a linear bearing, it has itty-bitty ball bearings living inside, awwww… Anyway, yeah those were all starting to bind up & were wearing away gouges/trenches in the simple stainless steel (not hardened steel) rods from the Y-travel motion. We replaced the rods & bearings completely on one machine with hardened steel rods & non-cheap-chinese-quality linear bearings. … And are about to have to do the same with the other machine as well. In my opinion, thermistors should almost be considered in the ‘consumables’ category on lower-end machines… We’ve had to replace the thermistor on one machine once, twice on the other. Yet, even when the thermistors were fine I’ve had “Thermal Runaway” as the the extruder is heating up for a print.

I’m sure I’m missing some things… Like I said, I hate posting negative things, but this had to be done. Please, consider a more pro-sumer choice versus the ‘Original Prusa i3 MK2’ if you need to run any kind of repetetive production runs, if you need a work-horse that you don’t have to think about. This machine will be fine for some of you, but not for others… not for established shops that need to get shit done.

[keebie81]

Have you tried lulzbot? I have had great results with mine and they have phone support which is helpful

[cobnut]

Hi @jhcs_mike I won’t down vote your comment because it’s clearly heartfelt and from someone that knows what they’re talking about, however, I will make some comments that hopefully you’ll treat with the same courtesy.

I’ve owned my Prusa i3 Mk2 for over a year now and since 3D printing is my primary business - not a hobby - it runs pretty much 24/7, it’s printing right now in fact. Has it been totally problem free? No, of course not, the original bearings were awful, so I replaced them, it also put a hole in a freshly fitted PEI sheet during calibration a while back, but that’s it. In a year. I know other Hubs and printers who’ll say similar things. It is odd that you’ve had problems with both machines, if it were just one I’m sure you’d agree that one was probably a lemon, but these failures do seem to be very uncommon for the Prusa - just look through this board and see how few bad experiences are reported. Maybe it was the batch they were bought in, maybe their quality has dropped (you don’t say when you bought the machines), I don’t know, but your experience does seem to be unusual.

I’d also suggest that buying for a professional environment, knowing that the machine(s) would be hard tasked, I probably wouldn’t have opted for a budget printer like the Prusa. When I bought mine I was just starting out, I had no idea how many orders I’d receive, or how busy I’d be, if I could go back in time I wouldn’t buy the Prusa now (in fact I’d probably not buy FDM at all, but would concentrate on SLA).

Never does the phrase “you get what you pay for” apply more than in 3D Printing, and if you’ve bought a Prusa, sitting pretty much towards the bottom end of the market in terms of price, then expected it to deliver professional levels of output, then perhaps you were asking too much.

[jhcs_mike]

Hi Keebie, I have actually used Lulzbots in the past! I have never owned one though. I currently own 3 Afinia “H480’s”, 2 Leapfrog “Creator Dual’s” , 1 Zortrax “M200” (soon to be 2), 1 Rapidelite 200, 1 Xmachines “Lorei Dual”, 1 Full Spectrum Laser “Pegasus Touch”, 1 Kudo3d “Titan 1”, 1 Formlabs “Form1 plus” and 1 3DPlatform “Workbench”

[jhcs_mike]

Hey cobnut! Thanks I do appreciate your viewpoint! Perhaps you missed or glanced over the bit where I stated: “Unfortunately I came onto the project after decisions had been made about the purchase of 3D printing gear, Including 2 “Original Prusa i3 MK2” machines.” No worries. I am also running a several tens of thousands of dollars Stratasys machine which the company purchased… have mixed feelings about that one too. Anyway, I believe these two were purchased, together, at the end Feb/ beginning of March. Believe me, I find it very odd that the problems have occurred in both! In well under a years time. This was also a huge reason for my write-up.