Prusa mini : The cursed printer ?  

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Maker's Lab
(@makers-lab)
Active Member

Hello Prusa's owners, ^^

 

I'm a French Maker that already own three 3D printers and the prusa mini's my fourth...
I also make videos on youtube about engineering...

 

I received my prusa mini June 15th and it was marvelous, it was working perfectly and the quality of the prints blow my mind... I made a video review of the prusa mini in french on my youtube channel, for me this was the perfect 3D printer...

 

1 week and 20h of printers later, issues started to come, first the extruder was clicking and
after a (very) short investigation, i discovered that the PTFE tubes that are in the heat-break and in the feeder were too short, so i changed those with tube that i had in stock...

 

The prusa mini worked perfectly for about 10 hours more...
I notice the same problem, but I wasn't able to fix it even with the tutorials on the prusa knowledge base, for me, the groove on the gear wasn't deep enough and the filament can't be pushed into the extruder... I also changed again the PTFE tube in the heat break and I did not have any difficulties to push myself the filament into the nozzle... But each time, after about 10 minutes of print, the extruder was clicking and the filament was sanded by the gear...

 

I reached the prusa support and I spent 4 hours with a very friendly support guy, and by the end of the day, a replacement feeder gear was ready to ship, i received this part yesterday and I changed it, the printer was running like before the incident... For 15 minutes :/

 

After a deeper look into the prusa forum, I notice that there is an engineering issue with the heat-break and the extruder, for the heat-break I'm not able to explain what can be issue but
for the feeder, and in comparison to the CEL ROBOX, the groove are not DEEP ENOUGH...

 

In conclusion :
After only 2 weeks of service, my printer seems dead... This is my first Prusa, and I am very disapointed of the Prusa Mini...
A lot of my subscribers asked me if it is a good beginner printer as prusa said, honestly I can't recommend it for a beginner, the's still too many issue for me to be as good as some Chinese printer and it hurt me to say that because I love prusa's products...

 

So, what should I do ?
I'm not the only one asking after prusa to fix their printers, for some of them since January... (And for me the thing that shows prusa's screwed up is Bondtech selling upgrade kit for prusa printer, I can understand this for 200€ Chinese printer but not for a prusa that is a symbol into 3D printing world)
I don't think it's ok for a 400€ printer that need to be fixed only 3 weeks after the first start...

 

Thank you for having taken the time to read me.
Awaiting your reply 🙂

 

Alexandre & Marc from Maker's Lab

 

 

This topic was modified 1 month ago by Maker's Lab
Posted : 12/07/2020 11:29 am
atomleef liked
kaucukovnik.vi
(@kaucukovnik-vi)
New Member

I have to agree with you. I have received the printer a couple days ago and it's been mostly unpleasant experience.

The overall feeling is that they pushed the price down really hard to get just below 10k CZK and it shows. It's generally a wonderful machine marred by relatively small, but fatal flaws.

At first I was amused by candies included in the package and extensively mentioned in the instructions. Then I realized that they are in fact damage control - "we know our machine is going to make you furious, here, have a candy!" I for one would have appreciated proper heatbreak or functioning screws instead.

Despite the brand reputation, Prusa Mini seems to be a very rough first experience with 3D printing. I'm very angry right now so I will leave it at that.

Posted : 12/07/2020 5:41 pm
Maker's Lab
(@makers-lab)
Active Member

Sure, i'm sorry if it is your first experience with 3D printing :/ Hopefully, all 3D printers don't have those kind of issue...

In an another way, and as i said into my post, prusa mini was for me a reliable small 3D printer for my tiny mechanical parts that need precision. I was about to bought it on Maker Faire Paris in November were i was an exponent, i finally order it in January to get it delivered in June :/ ...

The candies are given into all prusa 3D printer, but the issues begotten by the engineering mistakes are disappointing. I don't have a problem with 3D printers that got issues in the first month/year of the marketing, but the thing that drives me crazy is that prusa do not seems to fix their printer, the PTFE tube issue was pointed out in January but it isn't fixed yet. In regard with the heat break i think i will order the Bondtech one that looks bullet proof, i will probably talk talk about it in my future video... And it is not the fault of the filament, as my filaments all failed i switched to the prusament given with the mini

I am awaiting for other post to confirm the way i think, and i have to think on the bright side in concern with those issue...

Posted : 12/07/2020 6:26 pm
kaucukovnik.vi
(@kaucukovnik-vi)
New Member

Am I getting it right that Bondtech is the very same manufacturer that supplies Prusa with some of the default components? Because if so, this situation is pretty much inexcusable. Especially since the order was delayed by several months.

I'm on the verge of refunding just out of principle.

Posted : 12/07/2020 8:31 pm
Maker's Lab
(@makers-lab)
Active Member

I don't know if bondtech is a Prusa supplier for any part, if anyone have a clue about that i'm interested !

By the way and because you're talking about that you're wright, i had about 6 month of wait to get printer, i passed my order January 26 and received my printer June 15, i understand that Prusa was bored by proving medical supply when the Covid19 was hitting to top of the curve but we never had any email noticing us that the delay was extended... When i talked to the support team they were always very kind and friendly regarding the customer 🙂 ... The support guy send me via UPS a replacement feeder gear in one day...

In an other words i'm very concerned by all the beginners that bought a Prusa mini and are stuck due to a part that have an issue, especially if it is the source of a critical error on the printer... Those are very common (mistakes during conception) but what i worry about is the silence around those issue...

Posted : 12/07/2020 8:44 pm
bertuk
(@bertuk)
Active Member

Receive my Mini late March - just as lockdown became serious in the U.K. Yes, some very troubled initial printing but once I went through the whole cycle of resetting the heatbreak PFTE etc. I have been printing now without any issue for the last three months. Daily printing in ASA, PETG and PLA and going strong. Had to replace the heatbreak PFTE two times in total and no issues whatsoever. So, yes, some may be less fortunate with troubled machines, but there are plenty of us who are perfectly happy with the little Prusa Mini!

This post was modified 1 month ago 2 times by bertuk
Posted : 12/07/2020 9:54 pm
Karl Herbert
(@karl-herbert)
Famed Member

@makers-lab

@kaucukovnik-vi

It's a pity that you didn't have much good experience with your Prusa printers. I myself don't own a MINI, but I have heard of problems with the extruder. Maybe you'd like to take a look at this upgrade. I know it shouldn't be necessary with a new printer, but if you already own one, you might consider upgrading it.

https://forum.prusaprinters.org/forum/user-mods-octoprint-enclosures-nozzles/different-hotends/paged/2/#post-225920

Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen....
Posted : 12/07/2020 10:04 pm
kaucukovnik.vi
(@kaucukovnik-vi)
New Member

I would have already tried reseating the heatbreak, but the 3 grub screws were busted right out of the box.

My Mini was actually printing pretty well at first, and sometimes still does, but it's hit and miss with no apparent rhyme or reason to it. I have managed a solid 4-hour print, followed by failure to lay down decent first layer. Same settings, just a different piece of a multi-part model.

Posted : 12/07/2020 10:19 pm
ben.kindt
(@ben-kindt)
Active Member

Ugh....

I guess I’m going to order an i3 MK3S instead.  My inner voice tells me to give the 3D printing hobby another 3-5 years to mature before buying in, but it does seem like a lot of fun when the printer is behaving.

 

 

 

Posted : 12/07/2020 10:55 pm
Kiwo
 kiwo
(@kiwo)
Eminent Member

Anet AM8 and now Mini. Mine works as expected out of box, no problems found, that would make me mad on the product (no upgrades yet; 1 month; 1,5 spools Gembird PLA used).  Nor some inside de/construction of printer since first assembly. Sure, had some bad time, but always that was human lazy-ness or mistake on my side.

Posted : 13/07/2020 7:00 am
Maker's Lab
(@makers-lab)
Active Member

So... If i understood correctly what you said, this is a rare issue that i encounter O_O" In this case maybe prusa will be able to take back my mini into warranty and patch it ? Again, what is getting me angry is that the PTFE tube issue is known and they did not patched it for about 6 month the first issue mentioning this was published...

I am looking to buy a Slice engineering head https://www.sliceengineering.com/products/copperhead%E2%84%A2 to fix my issue with me extruder as it seems to not come from the feeder... What do you think about that ? Will it cancel my warranty if i upgrade this part ? Is Prusa able to take back my printer to fix it for at least 2 years ( I have 2 Creality that are working perfectly since 2 years without any other maintenance than the common one ) ?

Posted : 13/07/2020 1:18 pm
kaucukovnik.vi
(@kaucukovnik-vi)
New Member

All right, I have read some more on the forums and I think I have identified the cause of most of my issues as shifting room temperature. Calibrating the nozzle height before every print job makes it way more reliable.

I could swear I watched an official video that emphasized the Mini being a fully featured scaled down i3 and NOT a lesser machine. Being upfront and clearly stating its weaknesses would go a long way to avoid bad newbie experience. There is nothing shameful about a considerably cheaper machine not being as good as "the real deal".

Posted : 13/07/2020 5:44 pm
Rat_Patrol
(@rat_patrol)
Eminent Member

I received one of the first shipments of the Mini. Something that I said to many folks who were interested was to NOT be a beta tester on a new design unless you already have plenty of 3D printing experience and are willing to work through it. 

After a lot of issues at first, which ended up being 3, count them 3 bad MINDA probes (including a trip back to Prusa from the USA on Prusa's dime to diagnose and fix the last MINDA probe), my Mini has been a reliable workhorse with a few hundred hours of printing at least on the clock over several months. At this point, I can start a print and walk away without any worries of what I will get.

Mods: Bondtech extruder. This is ONLY because I wanted to print flexibles, and the stock extruder does NOT work well with flexibles. The stock extruder will work with a semi-flex, stiffer TPU, but not anything you would call a flexible unless you were printing at literal snail's pace. The Bondtech does a wonderful job with flexibles, but still take into consideration the Mini is a Bowden setup, so keep your feeds and speeds in check.

Upgraded the Bowden tube to Capricorn tubing. Honestly, I saw zip, zero no improvement whatsoever. As short as the Bowden tube is, I just didn't see any remarkable improvement with the Capricorn. Doesn't hurt I guess though.

I did also purchase the Bondtech upgraded heat break, but I have yet to install it. I haven't had any heat-creep issues with the stock heat break. Next time I tear into the hot end, I'll install it.

Posted : 13/07/2020 6:15 pm
bobstro liked
bobstro
(@bobstro)
Illustrious Member
Posted by: @kaucukovnik-vi

All right, I have read some more on the forums and I think I have identified the cause of most of my issues as shifting room temperature. Calibrating the nozzle height before every print job makes it way more reliable.

Are you aware of the discussion on warming up the MINDA probe to a consistent temperature before mesh bed leveling? I don't have a Mini myself, but I do follow many of the discussions. Some users are reporting better success by enforcing a MINDA warmup prior to printing. Something like hovering the probe over a heated bed for something like 5 minutes. 

I do something similar with my old v1 PINDA probe on the Mk3. Unfortunately, the MINDA doesn't have a temperature sensor built in, but you can monitor the temperature of an UNHEATED nozzle (hotend) thermistor to get a close idea. Unfortunately, there's no gcode command to do this, so it's a manual process for now.

I could swear I watched an official video that emphasized the Mini being a fully featured scaled down i3 and NOT a lesser machine. Being upfront and clearly stating its weaknesses would go a long way to avoid bad newbie experience. There is nothing shameful about a considerably cheaper machine not being as good as "the real deal".

Other than lines along the lines of "from the company that brought you the Mk3..." I can't say I have seen anything remotely like that, either from Prusa or any other source. They are markedly different designs, from the cantilever X axis to the use of a Bowden feed mechanisms. There have been heavily emphasized in every video or written description of the Mini I've seen. Not that those are shortcomings. In a smaller printer you don't need to worry about many of the issues that arise with larger parts.

The Mini is still definitely experiencing teething pains, but compared to issues I see with many printers at about the same price bracket, it still seems to be coming out ahead.  It's frustrating, but Prusa has a good track record of making incremental improvements to products over time.

 

My notes and disclaimers on 3D printing and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan...
Posted : 13/07/2020 7:47 pm
mirrad liked
atomleef
(@atomleef)
Estimable Member

i just have problem with ptfe tube, i curious why this happen. You guy answer my question- ptfe shrink. I will afraid it will come back again, so scary. Mini is my first printer, the only one. And in thailand there is no ptfe spare part sell here so sad and so scary. Supplier tell me to cut and use pencil sharpener to make ptfe tube. Will it be ok?

Posted : 14/07/2020 4:49 am
atomleef
(@atomleef)
Estimable Member

@kiwo

Is anet easy to use compare to prusa? What is disadvantage compare to prusa? thank you

Posted : 14/07/2020 4:52 am
greg-5
(@greg-5)
New Member

@atomleef

My first printer was an Anet A8, and now I have a Prusa Mini.

I spent a lot of time tweaking and re-building the Anet, and eventually got fairly reliable printing out of it after reinforcing the frame, replacing the extruder/hot end, rebuilding the firmware etc. This is great if you like tinkering, and you do learn a lot about how 3D printers work.

The mini is completely different - it just works. I have done nothing except bolt it together, switch it on and start printing. I've printed maybe 50 objects, and two have failed (because of bed adhesion, easily fixed by re-doing the built-in first layer calibration test). If you want to tinker with a 3D printer, get a clone. If you want to print, get a Prusa.

I'm aware of the shrinking PTFE tube issue, but it hasn't affected me yet. I'm confident that Prusa will address it, and I'm guessing the crazy demand  for this printer combined with the pandemic have delayed a fix more than they would like. On the other hand, if you get a clone, you're on your own.

One last thing - the mini is a really good size. I finally took the plunge after realising that in two years with the Anet I never printed anything bigger than the mini could handle. And because it is small and quiet, I've moved it from my garage to a cupboard in my office, which is much more convenient.

Posted : 14/07/2020 8:01 am
atomleef liked
greg-5
(@greg-5)
New Member

@atomleef

My first printer was an Anet A8, and now I have a Prusa Mini.

I spent a lot of time tweaking and re-building the Anet, and eventually got fairly reliable printing out of it after reinforcing the frame, replacing the extruder/hot end, rebuilding the firmware etc. This is great if you like tinkering, and you do learn a lot about how 3D printers work.

The mini is completely different - it just works. I have done nothing except bolt it together, switch it on and start printing. I've printed maybe 50 objects, and two have failed (because of bed adhesion, easily fixed by re-doing the built-in first layer calibration test). If you want to tinker with a 3D printer, get a clone. If you want to print, get a Prusa.

I'm aware of the shrinking PTFE tube issue, but it hasn't affected me yet. I'm confident that Prusa will address it, and I'm guessing the crazy demand  for this printer combined with the pandemic have delayed a fix more than they would like. On the other hand, if you get a clone, you're on your own.

One last thing - the mini is a really good size. I finally took the plunge after realising that in two years with the Anet I never printed anything bigger than the mini could handle. And because it is small and quiet, I've moved it from my garage to a cupboard in my office, which is much more convenient.

Posted : 14/07/2020 8:01 am
atomleef
(@atomleef)
Estimable Member

@greg-5

thank you

Posted : 14/07/2020 8:48 am
atomleef
(@atomleef)
Estimable Member

@greg-5

"reinforcing the frame, replacing the extruder/hot end, rebuilding the firmware etc." This look troublesome T_T. I do not have much time to modified it that much. Thankyou fpr sharing. 🙂 Bad pint of prusa in my country is service is rarely provied.

Posted : 14/07/2020 8:52 am
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