At the end of my patience i3MK2  

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robert.w3
(@robert-w3)
Active Member

This machine has been nothing but trouble since I bought it.  I have fought with the machine constantly.  in the time I have had it i have had three fans fail, a motor fail, the Z calibration go bad and the feed motor skip so feed is inconsistent.  the machine also resets randomly so that the print just stops in the middle, usually about 30 min to and hour in.

This started 6 months after I owned the machine.  It took 4 months to convince Prusa that it had a bad fan and it wasn't a plugged nozzle.  then the material would not adhere to the heating plate.  2 months more of discussion and whoops, its out of warrantee, everything now costs a fortune to fix or repair and I if I hear about a plugged nozzle 1 more time I will do something drastic.

Now the feed motor is skipping again and the resets are happening every 2 or three print attempts.  I wish i had never ever purchased this nightmare.  I am using filament from Prusa and have checked temperature ranges from 210 to 240 for PLA.  I have tried bed temperatures from 50 to 72 degrees.  I have run over 50 calibration cycles and done so many z-calibrations don't need the screen any more. 

I thought I would make one more attempt and I achieved 1 print.  Now its back to the same issues: Skipping motor, won't stick to the bed, filament flow is inconsistent and random resets that stop the print. 

I'm just about done.  If I could find a way to off load this onto someone else for even some of the money I put into it, I would in a heartbeat.

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Posted : 05/07/2019 8:35 pm
Tim
(@tim-m30)
Illustrious Member

Kit or prebuilt?

It is always wise to get more than one opinion......
Posted : 05/07/2019 8:51 pm
robert.w3
(@robert-w3)
Active Member

Pre-built.  I tried to make my entry into the printing as easy and with as much support as possible.  It just didn't work.

I should also mention I am not trying complex prints.  I use the Treefrog as my calibration tool because i have found the front legs can indicate problems that the little boat everyone uses seems to miss.  I have had failures and resets even on trying to print the prusa logo.  I am printing from and SD card, not over USB

This post was modified 1 year ago by robert.w3
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Posted : 05/07/2019 8:55 pm
Tim
(@tim-m30)
Illustrious Member

What was the first failure you experienced?  The one six months in?  I ask because that seems to be when things fell apart and you started having painful issues.

 

It is always wise to get more than one opinion......
Posted : 05/07/2019 9:08 pm
robert.w3
(@robert-w3)
Active Member

The smaller fan that cools the heating element was the first to fail.  It would spin but with no air movement.  It was a weird problem and it took 4 months before Prusa would recognize that the problem wasn't a clogged nozzle.  I eventually had to send a video of me cleaning the nozzle before they would look at alternatives.  And you're right, nothing worked right after that.  The worst problems are the inconsistent flow and the problems with the miscelaneous restarts in the middle of a print.  I've used a IR temperature probe to check heat and nothing is getting too hot and a voltmeter to verify I'm not getting voltage sags.  It's also on my computers UPS and surge protector 

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Posted : 06/07/2019 12:05 am
nikolai.r
(@nikolai-r)
Noble Member

I would suggest you check for someone in your local area on the Prusa Map. What you're describing are regular issues after wear and tear. I think either the cooling element got dirty or the fan cable broke and you got your nozzle/extruder clogged. After that happens you might have many side effects as a result.

Often linked posts:
Going small with MMU2
Real Multi Material
My prints on Instagram...
Posted : 06/07/2019 12:23 am
robert.w3
(@robert-w3)
Active Member

The CPU and power supply shutting down for no reason is wear and tear? The nozzle has been replaced and the port is a perfect 0.4mm.  the extruder is bare metal clean as of this morning.  the Fan cable was replaced with the fan which is brand new (both of them)  the unit has maybe 20 complete prints on it and maybe 30 hours of total run time (Lots of time not running, but only 30 hours where material is actually passing though the extruder. 

If that's the case then I am done.  For the time and money i have invested in this thing, I could buy the prints I wanted and use modeling putty to make the modifications I wanted. 

To note:  I did get one good print this morning, then it went back to its old tricks and wont work again.

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Posted : 06/07/2019 12:30 am
nikolai.r
(@nikolai-r)
Noble Member

My original MK2 had cable issues as-well. But I assembled it myself, so I blame myself for that.

Power Supply doesn't last long if you put it in a hot environment.

So yes, this things are wear and tear. But I can't tell if your printer has the same issues or any other. Based on my experience the Prusa Printers are pretty reliable and don't require any MUST-HAVE modifications to run. But they also have many moving parts which operates at a high temperature. Maintenance of such devices is part of the fun.

This post was modified 1 year ago by nikolai.r
Often linked posts:
Going small with MMU2
Real Multi Material
My prints on Instagram...
Posted : 06/07/2019 12:46 am
Tim
(@tim-m30)
Illustrious Member

A spinning fan will move air unless the fan is blocked. Physics.  Unless the fan was spinning slow, which is possible, but I thought even the MK2 used the tach to sense fan speeds. Maybe not. But fans do fail, and on a moving extruder they fail prematurely since the motion causes increase forces on the bearings. 

A hot end that doesn't have adequate cooling can allow heat to creep up the heat break, and plastic will get gooey and jam. Especially after the fan is fixed.   Have you checked the heat break for old melt?  Might be easier to simply replace it ($16 Amazon).  I replaced mine a while back.  Not something you normally expect to "fail" but easier than cleaning. If I ever get around to cleaning the old one it'll be a great spare.

As for the stopping mid-print?   If a bearing is seizing up, that'll certainly cause problems, and bearings are sadly not very good on these printers.  I've gone through two sets now.  First set failed quickly - I never greased them (my bad). Second set were packed with grease but installed on old rods (again, my bad).  This time around I'll replace rods and bearings.

You can check for sticky bearings by powering down and moving the extruder by hand. left-right to the stops; same for the bed. If the motion "sticks" anywhere along the stroke, the motors may not be able to handle the extra friction and stall.  The MK3 has crash detection. Not sure if the 2 has that feature. But a crash (motor stall) stops the print. 

Those are a couple ideas of what to check.  Not being in front of the printer limits diagnostics.  So it's up to you to notice the details around what is happening.  Temps wiggling? Odd noise or sound when it stops? Etc.

 

It is always wise to get more than one opinion......
Posted : 06/07/2019 3:55 am
robert.w3
(@robert-w3)
Active Member

To be correct there is spinning and windmilling.  not all moving fans move air and not all fans moving air move much.  In this case the fan was spinning but not fast enough to actually move any air.

From what I see, this is not apparently unacceptable behavior for the hobby so it is definitely not the hobby for me.  I looked at the technology and the only new thing is the software.  Everything else is at least 20 years old and there are no new ideas here.  I was expecting to have to find flow rates and apertures and speeds to get good prints.  Instead I find the interesting bits about printing are locked where i have to either build my own software or live with what is pre-determined.  I also find that technology that should be robust (industrial grade stepper motors for this size are about $200 in the servo industry) small extrusion chambers are also nothing new to the plastics industry.

If this had been a Chinese knock off i would have expected unreliable equipment.  For the price I paid for this I expected quality hardware.  To me quality hardware is at least 2000 of run time.  That isn't even close to what I am getting and I get no joy from fighting with mechanical equipment. (making things run beyond their capacity, yes; optimizing quality, yes; but plug and play replacing parts because something broke again?  I can buy and old car and get that experience)

As I said earlier, I bought it to save money on terrain for wargaming and to do some customization.  I have not saved any money and I have increased my stress levels.  this is not what I am after so I will have to find a different hobby

But to answer your last questions:

Temps are steady at 217 deg

the only indication that it stopped is that the screen goes dark and then lights up again with the initialization page, there is no other warning.

there is no noise, only the lack of it. 🙂

Roo

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Posted : 07/07/2019 7:46 pm
Tim
(@tim-m30)
Illustrious Member

Sorry to hear - but if you've replaced three fans, that seems to me you've got plenty of hours on the print.  Random resets are known to be caused by short circuits in the bed heating circuitry (broken wires from use), and from some failure in the LCD panel (the reset button somehow fails). 

As for the rest of the complain that FDM printing is too old a technology and you can't enjoy it because everything has already been done and hidden so you can't explore the technology.  That's bull crap.  In Slicer you can change so many settings and totally corrupt a part it is unfathomable.  A real scientist would be taking the existing technology and building upon it; not complaining everything has already been discovered.  Have you tried printing metals with the MK2?  Seems like a great avenue to explore. And I can assure you few have been done that path.  

None of this is helping to get your printer working.  The time to ask for help was six or more months ago when you first started having problem. Right now you are just complaining and not really helping us help you. Which, I've been there and fully understand the frustration, won't help with resolving the problems.

Step back: identify and list the most obnoxious and common of the many problems you are having.  From that list maybe a set of symptoms will help illuminate a problem you can actually fix.  Once one problem is solved, then move to the next item on the list.

It is always wise to get more than one opinion......
Posted : 07/07/2019 8:09 pm
bobstro liked
robert.w3
(@robert-w3)
Active Member

What I said was I didn't want to put up with the reliability issues.  Yes I there might be advanced features but if I only get 10 prints between catastropic failure of the equipment in not going to get much chance to use them, am I? That's the total number of successful prints I've gotten: 10.  Since then in have invested 200 hours of my time and 300 dollars in parts and shipping over the course of 14 months.  That's 2 cases 4 frogs and 4 cobblestone street sections.

Would you continue to use your car if it got 10 trips between major trips to the repair shop?

And I did ask for help.  I asked tech support for tech support.  I got nothing of use except repeated requests to clean the nozzle. Then I had to work 70 hour work weeks for 4 months to keep my company among the living so I didn't really have time to hunt around in the forums.

I was hoping someone could point out a setting or repeatable problem to get it restarted.  I don't have the time to invest in repairs. I now have 7 weeks of travel to cram into this quarter so not going to have much time to work on it in the future either.

It just isn't for me, not now.  If it's not fixable in 4 hours, I just dont have the time for it any more

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Posted : 07/07/2019 11:17 pm
nikolai.r
(@nikolai-r)
Noble Member
Posted by: robert.w3

I was hoping someone could point out a setting or repeatable problem to get it restarted.  I don't have the time to invest in repairs. I now have 7 weeks of travel to cram into this quarter so not going to have much time to work on it in the future either.

It just isn't for me, not now.  If it's not fixable in 4 hours, I just dont have the time for it any more

Every 3D printer requires maintenance. Depending on what you're printing, you will have more or less trouble. I would suggest you get a service contract. Especially if you have very limited spare time, I would even outsource the printing part completely. Your expectations are way too high for any 3D printer and it doesn't make sense to waste your very limited time on that and even get upset about that. 

Often linked posts:
Going small with MMU2
Real Multi Material
My prints on Instagram...
Posted : 07/07/2019 11:36 pm
Tim liked
robert.w3
(@robert-w3)
Active Member

Pretty much my lesson learned.  Just wish I had learned it with a smaller price tag.

My eye for success is apparently much better with cars than printers since both cost the same and I've gotten 5 years of service from the car...

But my expectations were set based on the printing record of 3 mk2, an M3D, and a thingbot. All of them go about 2000 print hours without issue and then the issues are detectable and have known cures.

Life goes on

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Posted : 08/07/2019 7:53 am
Tim
(@tim-m30)
Illustrious Member

Wow - if I spent $35,000 on a printer that didn't work, I'd be upset, too!  

It is always wise to get more than one opinion......
Posted : 08/07/2019 8:49 am
robert.w3
(@robert-w3)
Active Member

<Smirk> 🙂 

Low cost cat, not high end printer.  The Volvo in my driveway cost around 800 USD.  

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Posted : 08/07/2019 10:07 am
nikolai.r
(@nikolai-r)
Noble Member
Posted by: robert.w3

Pretty much my lesson learned.  Just wish I had learned it with a smaller price tag.

You can sell your printer for a reasonable price. The resell value of Prusa printers is pretty high.

Often linked posts:
Going small with MMU2
Real Multi Material
My prints on Instagram...
Posted : 08/07/2019 6:11 pm
bobstro
(@bobstro)
Illustrious Member
Posted by: robert.w3

<Smirk> 🙂 

Low cost cat, not high end printer.  The Volvo in my driveway cost around 800 USD.  

As a dog owner, I was very confused for a second. Sure, you can get a reasonable car for the what you sink into a 3D printer, but pets are a whole 'nother level of expense.

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 : 08/07/2019 6:17 pm
robert.w3
(@robert-w3)
Active Member

I so hate autocorrupt that should be car not cat 🤣 

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Posted : 08/07/2019 7:33 pm
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