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Prusa Extruder Body Melting  

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SweetnSourKandy
(@sweetnsourkandy)
New Member
Prusa Extruder Body Melting

Hello,

I just received this Prusa i3 MK2 prebuilt about 2 weeks ago, or a couple days over that. I'm happy with it but this concerns me.

I don't print with it 24/7 and I only printed PLA @ 200 degrees. This shouldn't even melt the abs extruder body and the air coming out of it is very cool, and it isn't hot at all to the touch. I did less than 10 prints on it. I was wondering if this is normal, because I feel I shouldn't have to replace the extruder body already. It is also coming apart at the bottom.

I am also in an air conditioned apartment, and the room isn't hot. I don't want to have to keep replacing the extruder body every couple months.

I purchased the printer prebuilt because I was not confident in building it, and figured at least the extruder body would last at the least 6 or so months of moderate to heavy use. I printed 4 small items on it (a couple with 2 parts), but each print lasting at the most 5 hrs.

I always shut the printer off right after a print and only keep it preheating long enough to load/unload, or take off a print.

Here is a picture below, look in the vent bit of the extruder head, its starting to melt. (Sorry the print bed is messy, I been printing a project on it (PLA, 200) and that's all glue).

screen cap

Veröffentlicht : 04/11/2016 4:35 pm
Llarrinye
(@llarrinye)
New Member
Re: Prusa Extruder Body Melting

If you're switching the printer off straight after a print then that's your problem. You need to let it cool down with the fan still running otherwise the heatsink heats up and will melt the plastic and cause possible blockages.

Veröffentlicht : 04/11/2016 5:25 pm
PJR
 PJR
(@pjr)
Antient Member Moderator
Re: Prusa Extruder Body Melting

And why use glue when printing with PLA?

Totally unnecessary. Just get the probe/nozzle adjusted correctly and only use glue stick for the filaments that need it.

Peter

Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…

Veröffentlicht : 04/11/2016 5:57 pm
SweetnSourKandy
(@sweetnsourkandy)
New Member
Themenstarter answered:
Re: Prusa Extruder Body Melting

@PJR : I used glue with printing PLA because sometimes the first layer lifts up (when it starts or maybe even a good bit into the first layer). I tried other solutions such as isopropyl alcohol recommended on the Prusa youtube channel for adhesion (with a clean bed). But sometimes some parts of that first layer like to drag or don't lay down, and the glue helped it out. I don't use it all the time, but for the print before the one (which consisted of several parts), I needed it.

I am fairly new to 3d printing so any other suggestions would help. The bed temp is 60. I also raised the temp of the last print to 210 instead of 200, so that could had helped too.
_________________________________________________________________________________________________

Thanks for the response. That does make sense.

I should be more specific. I don't power it off right after the prints finish since I like to preheat to assist with taking off the print. (Maybe I should look into learning to preheat the bed only...its probably there in the settings).

I am guilty of after I take off my print, I turn it off, instead of turning on the cooldown setting. So that is the culprit. I'll start cooling down now before turning it off.

Guess it's different with a printer made with 3d printed parts instead of the other ones I am used to. (Not bashing the printer, but I mean it's something to be conscious of for now on with a 3d printed extruder head instead of steel/metal parts like some others).

Veröffentlicht : 04/11/2016 6:08 pm
ayourk
(@ayourk)
Reputable Member
Re: Prusa Extruder Body Melting

@PJR : I used glue with printing PLA because sometimes the first layer lifts up (when it starts or maybe even a good bit into the first layer). I tried other solutions such as isopropyl alcohol recommended on the Prusa youtube channel for adhesion (with a clean bed). But sometimes some parts of that first layer like to drag or don't lay down, and the glue helped it out. I don't use it all the time, but for the print before the one (which consisted of several parts), I needed it.

I am fairly new to 3d printing so any other suggestions would help. The bed temp is 60. I also raised the temp of the last print to 210 instead of 200, so that could had helped too.
_________________________________________________________________________________________________

Thanks for the response. That does make sense.

I should be more specific. I don't power it off right after the prints finish since I like to preheat to assist with taking off the print. (Maybe I should look into learning to preheat the bed only...its probably there in the settings).

I am guilty of after I take off my print, I turn it off, instead of turning on the cooldown setting. So that is the culprit. I'll start cooling down now before turning it off.

Guess it's different with a printer made with 3d printed parts instead of the other ones I am used to. (Not bashing the printer, but I mean it's something to be conscious of for now on with a 3d printed extruder head instead of steel/metal parts like some others).

You could always come join us in the Prusa MK2 Google Hangout. Lots of people there already that have varying different degrees of experience.

It sounds like parts of your printer might not be square, or your PINDA probe might not be adjusted quite right for the adhesion issues, that is if you are sure that Isopropyl Alcohol didn't fix the issue.

Dimensions PNG

and an 8 inch (200mm) or greater caliper is recommended.

Veröffentlicht : 04/11/2016 6:22 pm
christophe.p
(@christophe-p)
Mitglied Moderator
Re: Prusa Extruder Body Melting


Thanks for the response. That does make sense.

I should be more specific. I don't power it off right after the prints finish since I like to preheat to assist with taking off the print. (Maybe I should look into learning to preheat the bed only...its probably there in the settings).

I am guilty of after I take off my print, I turn it off, instead of turning on the cooldown setting. So that is the culprit. I'll start cooling down now before turning it off.

Guess it's different with a printer made with 3d printed parts instead of the other ones I am used to. (Not bashing the printer, but I mean it's something to be conscious of for now on with a 3d printed extruder head instead of steel/metal parts like some others).

Hi,

I'm not sure what you are calling cooldown setting.

Anyway you do not have to activate anything, it's automatic: the fan that cooldown the extruder (the small one on the left) is triggered as soon as the extruder reach 50 °C and only switch off once the temperature go below 50 °C. The only thing you have to do is to wait for it to switch off, meaning that the extruder is reasonably cold.

I'm like Jon Snow, I know nothing.

Veröffentlicht : 04/11/2016 6:32 pm
SweetnSourKandy
(@sweetnsourkandy)
New Member
Themenstarter answered:
Re: Prusa Extruder Body Melting


Thanks for the response. That does make sense.

I should be more specific. I don't power it off right after the prints finish since I like to preheat to assist with taking off the print. (Maybe I should look into learning to preheat the bed only...its probably there in the settings).

I am guilty of after I take off my print, I turn it off, instead of turning on the cooldown setting. So that is the culprit. I'll start cooling down now before turning it off.

Guess it's different with a printer made with 3d printed parts instead of the other ones I am used to. (Not bashing the printer, but I mean it's something to be conscious of for now on with a 3d printed extruder head instead of steel/metal parts like some others).

Hi,

I'm not sure what you are calling cooldown setting.

Anyway you do not have to activate anything, it's automatic: the fan that cooldown the extruder (the small one on the left) is triggered as soon as the extruder reach 50 °C and only switch off once the temperature go below 50 °C. The only thing you have to do is to wait for it to switch off, meaning that the extruder is reasonably cold.

When I go into settings, while I am preheating or into the menu, it's something that says "cooldown", which cools down the printer, basically stops it from preheating.

Veröffentlicht : 04/11/2016 6:55 pm
ayourk
(@ayourk)
Reputable Member
Re: Prusa Extruder Body Melting


Hi,

I'm not sure what you are calling cooldown setting.

Anyway you do not have to activate anything, it's automatic: the fan that cooldown the extruder (the small one on the left) is triggered as soon as the extruder reach 50 °C and only switch off once the temperature go below 50 °C. The only thing you have to do is to wait for it to switch off, meaning that the extruder is reasonably cold.

When I go into settings, while I am preheating or into the menu, it's something that says "cooldown", which cools down the printer, basically stops it from preheating.[/quote]

But that doesn't automatically stop the fans.

Dimensions PNG

and an 8 inch (200mm) or greater caliper is recommended.

Veröffentlicht : 04/11/2016 8:13 pm
MrMik
(@mrmik)
Honorable Member
Re: Prusa Extruder Body Melting

I don't think your extruder body is melting at all.

It is not screwed together quite right, and it has imperfections that happened while it was being printed.

I think it probably looked like this all the time but you did not notice it earlier, and it has probably no effect on print quality.

Fo your first layer adhesion problems, you need to learn to use live z-adjust rather than glue for PLA.
PLA does not need glue on the bed.

Veröffentlicht : 05/11/2016 12:32 am
StephanK
(@stephank)
Reputable Member
Re: Prusa Extruder Body Melting


I don't power it off right after the prints finish since I like to preheat to assist with taking off the print.
[...] after I take off my print, I turn it off, instead of turning on the cooldown setting. So that is the culprit. I'll start cooling down now before turning it off.

I think this got overlooked by the posters before.

If I understand you correctly, this is your current "workflow":

1) Print finished
2) Sometime later you manually turn on Preheat in order to make removal of the printed parts easier
3) You used to turn off the printer without cooldown. But you plan to use cooldown now

Correct?

If so,

First of all: Yes, when using the preheat function for whatever reason, then go to Cooldown and wait for the temperatures to drop before turning off the printer. (Extruder fan will get turned off automatically once the nozzle temperature drops below 50°C)

However, when printing with PLA you shouldn't have to use Preheat to remove the parts. And certainly no glue. PLA can be printed with no glue or anything directly onto the PEI sheet on your bed. After the print finishes, wait till the bed cooled down all by itself to roughly 30°C. Now it should be fairly easy to get PLA parts off. There should be no need to reheat the bed using Preheat. Live adjust Z should be all that's needed. If that's not enough to get your prints to stick (and release afterwards), then maybe post a few pictures how the first layer is looking on the print bed while printing and maybe the bottom of a finished print, so we can get an idea what's going on.

Veröffentlicht : 05/11/2016 5:27 am
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