Multiple print failures  

RE: Multiple print failures

I'm curious to know if a simple cube or cylinder would also fail. The temp change on the display is my concern. That should not be happening with the pre-generated code. I am at a loss for an explanation of that behavior.

So frustrating to experience this problem during prime time holiday season. I feel for you. Do keep at it! 

RE: Multiple print failures

Posted by: @bobstro

I'm curious to know if a simple cube or cylinder would also fail. The temp change on the display is my concern. That should not be happening with the pre-generated code. I am at a loss for an explanation of that behavior.

So frustrating to experience this problem during prime time holiday season. I feel for you. Do keep at it! 

I didn't actually observe the temperature change on the Prusa frog printing, but was not recording then.  However, failure was exactly the same as with other parts.

I am now going to keep printing Buddy models (this is a Prusa code provided on their SD card) and record the display, even though this means re-staring the video recording every 30 minutes and changing cameras when the batteries run out. Or until my patience runs out and I post it back to Prusa!!

RE: Multiple print failures

@bobstro,

Are you sure that the left hand is the set temperature?

I am recently not with my printer , but I would bet the left hand number is the measured one. Will check immediatelly I am at home.

RE: Multiple print failures

@zoltan

No, I believe the right hand is the set temperature which stayed where it should be  It is the left hand reading that dropped.

RE: Multiple print failures

@epzcaw wups, brain cramp. Ok, that makes more sense. Does the temp drop quickly or drift? 

RE: Multiple print failures

@epzcaw

I agree with you

@bobstro posted: The left-hand temp value shows the settings value, so if that changes while printing the sample gcode, something is way off.

So in my previous post i questionmarked @bobstro's statement

RE: Multiple print failures

Nothing is ever simple.   I started printing "Buddy".  It is 150um layer thickness, 2 hour printing time.

It failed after about an hour at a height of about 26.5mm

I videod the display throughout the process.  The nozzle temperature did not vary by more than a degree either way from teh required value.  However, round about the failure time, the bed temperature dropped from 60 to 45, returning again to 60.  This took place over two minutes.   I don't know if bed temperature is significant or not - hard to see why it should have such a dramatic effect.  But the nozzle was blocked when I started  a new print, and I had to unload and re-load the filament to get going.

So????

RE: Multiple print failures

Crazy idea - is your power supply of your 240V stable? 

Decrease could influence the heating power.

Btw. which firmware do you have recently installed?

Those temperature fluctuations could be the result of faulty current controllers.

RE: Multiple print failures

@zoltan Board and electronics are run off 5V (Arduino) stepped down from 24V, no? The 24-5v convertor could step up a sagging 24V input to keep the board and display alive while the 24V being fed to the heaters and motors sags, could it not? 

RE: Multiple print failures

The MK3S power supply has a drop-out detection circuit that would trigger a power fail-alert at the Einsy; and normal power-fail recovery would be invoked.

RE: Multiple print failures

Posted by: @zoltan

Crazy idea - is your power supply of your 240V stable? 

I'm nor sure how I can find that out but I think the generating companies have an obligation to keep the supply. I've found something that says it is 230V +10% and -6%

Decrease could influence the heating power.

Btw. which firmware do you have recently installed?

I haven't installed the most recent one.  I guess I should.

Those temperature fluctuations could be the result of faulty current controllers.

RE: Multiple print failures

I told you crazy idea 😊, but the real life can create situations that no writer is capable to imagine.

This leads me to the question @epzcaw please, do you have a feeling the power supplier or the einsy does not heat too much? Could be also power supplier fault after heating up not feeding enough voltage.

5 V step down regulator for einsy could hadle this but the heating controllers are operating with 24 V.

Reading your profile I also appologize for some stupid questions 🥀 I could issue in the past.

I am not sure whether the 24V is stabilised. The heater resistances do not care exact voltage but when it is not enough they just do not heat enough. 

This was the reason of the question how long time takes to heat up from 22 to 225 degrees. 

RE: Multiple print failures

More confusion.

Treefrog failed at 2.5mm with no discernible change in either temperature.  Its a Prusa gcode, so must be machine failure.

Gets worse!

I think I will have to wait until Prusa gets back to me.

RE: Multiple print failures

Posted by: @tim-m30

The MK3S power supply has a drop-out detection circuit that would trigger a power fail-alert at the Einsy; and normal power-fail recovery would be invoked.

That's at the input is it not? A separate board in front (220V) of the power supply proper? I'm wondering if a drop in the 24v side might be an issue. 

RE: Multiple print failures

Posted by: @tim-m30

The MK3S power supply has a drop-out detection circuit that would trigger a power fail-alert at the Einsy; and normal power-fail recovery would be invoked.

That's at the input is it not? A separate board in front (220V) of the power supply proper? I'm wondering if a drop in the 24v side might be an issue. 

RE: Multiple print failures

@epzcaw - I imagine that you're getting a bit tired of repeating your story each time you contact support. I would create a story (novella?) outlining each step with pics that you can simply cut & paste to them each time. At this point, it really sounds like a hardware issue. Unfortunately, testing the power supply sounds like a next step, but you would need a meter and have to do some opening of the case. Even then, an intermittent issue could still evade detection. Was this a pre-built or kit?

Given all that you've done, if Prusa support doesn't come up with any better ideas, I'd ask for either a hardware swap or a full refund. Hopefully they'll do a swap and you can start afresh in the new year. You've been more than patient, and I commend you for your persistence.

RE: Multiple print failures

I thought you might all like an update.

As @bobstro suggested, I contacted Prusa and asked for either a refund or a repair. I said i would only accept a replacement if they gave me a fully assembled model (mine was a kit) but said I would pay the difference if they did this.  This is the reply I got

RE: Multiple print failures

It is sad , but I would say this should be the first step. Unfortunatelly we as customers,  agreed on terms, that in the kit situation Prusa does not take the liability for the assembled set , but only for parts.

At the moment you have the new hotend we could exclude it from the suspects list. 

RE: Multiple print failures

Uff. This should serve as a cautionary tale for anyone recommending wholesale replacement of Prusa-approved and authorized parts, no matter what "evidence" is provided. Swapping parts can cause warranty issues. Not that it would make a lot of difference in this case -- and at least @epzcaw is getting a replacement hotend -- but it would be a real shame if a pre-built warranty was voided.

RE: Multiple print failures

Posted by: @epzcaw

[...] We will replace your hotend. We also need to take your back for testing. Please add the original heatbreak from the printer back into the hotend. Within 2 days, you will receive a return label for thee hotend, along with the instructions to post it. As soon as the carrier picks it up, we will send a replacement hotend, and you will receive a tracking number.

I just re-read this. They're shipping a replacement hotend and are asking that the original hotend be returned. I thought you were being asked to return the entire printer!

That's actually pretty good. Once you've got it apart to stick the new one in, putting the old heatbreak back in the now-removed original hotend shouldn't be much work. They're being a little pissy about the "unauthorized" heatbreak swap, and they really should have offered up a new hotend originally if they're accepting now that there must be something wrong with it, but it sounds like you're getting the maximum level of warranty support for a kit. It is nice that they're shipping a replacement first instead of waiting for you to ship yours back.

Glad to hear you're at least making some headway with support. Here's hoping the new hotend fires up without fuss.