PEEK insulator melted

[alkerlouch 0]

Hi everyone !

I recently built my own Ultimaker from the kit and after a lot of settings I could print correctly some items using PLA.

Yesterday it appears that the peek insulator of the printing head began to melt.

The temperature I could read from Cura was 220°C for all my prints (I'm using Cura's default settings to print in normal quality).

I double checked the wiki to be sure I assembled it correctly and I did.

Any idea about what happened? A fix may be?

 

[SandervG 1,521]

I don't think you can un-melt your PEEK, so a fix would be to order a new one in the shop.

To find the cause, do you know if your blue led was burning while you were printing?

If it wasn't, your signal cable got disconnected, making it impossible to communicate the temperature to your electronics.

Resulting in infinite heating.

You could fix it by guiding the wires through the strain relief so it can not get disconnected again.

 

[gr5 2,177]

Are you sure the PEEK part melted? Or did you just get some leakage? Sometimes PLA leaks out through the edge of the PEEK. PLA can turn brown or black if you keep it hot for too long.

If it melted then something is wrong with your temperature readings. You need to fix this before replacing the PEEK part or you will melt it again.

 

[alkerlouch 0]

Well, there is for sure no way to un-melt it I was thinking about how to fix the problem.

The blue led was on, no problem with it. I read on some topic that the temperature can be wrong on the screen but the PLA was flowing normally (I mean a continuous flow but not really fast), my prints are quite accurate also and not totally melted. It doesn't sound like it's to hot

I'm sure the PEEK part melted, there are some bubbles on it. There's also some leakage from the PLA, i can see some silver but not that much.

Next step is to fix the problem, I'll try to get the temperature of any item and test the sensor on it but i don't have any clue about what to do if it turns to be ok.

PS: I'll send some pictures later on

 

[gr5 2,177]

>PS: I'll send some pictures later on

Please! I still think it's PLA leakage, bubbling, and melting but if those crisp corners and edges of the peek part are now droopy, soft, and rounded then of course it's the peek. The heater definitely has the power to melt the peek if it is stuck on. But PEEK shouldn't melt/deform noticeably below 300C (even though it's glass temp is 143C):

http://en.wikipedia.org/wiki/PEEK

I think I mentioned this but if you let PLA stay hot long enough it turns roughly the same color as PEEK and then if you wait long enough turns black.

 

[alkerlouch 0]

Here is the pic ! There's actually some silver PLA on it (it comes from leakage for sure) but look at the color of the peek. This is why I think there's a problem somewhere.

 

[SandervG 1,521]

The gradient can also come by heating itself, not necessarily overheating.

I do see some filament at the bottom of the brasstube, have you already fixed this leak?

Also, it is hard to tell, but is your Nozzle screwed in all the way to your alu heater block?

Looks like maybe there is a small gap in between.

 

[gr5 2,177]

is your Nozzle screwed in all the way

 

If you decide to tighten this be very careful as the brass nozzle is easy to break. Heat up to 200C and let it sit for 30 seconds before tightening.

 

[ken-zehnder 0]

Great post! I also recently assembled my UM1 and came here to find answers after melting my PEEK. I had sarted my first print (ultimaker man !) But I stopped after a short while when I noticed th print sliding sideways. Fixed a loose pulley.but left the temp at 210 or 220 for some time. Extruder quit working so I read about setting temp to 250 to clear a clogged nozzle. Fooled around reading wiki while nozzle was at temp and when I glanced again the nozzle was discolored and spewing burnt plastic droplets and some smoke. After cooling... PEEK plugged. Dismantled and hole through it plugged with material. Drilled out from nozzle side but now when reassembled filament jams at entrance to brass tube because its now off centr. I though of using 10 mm spacers at bottom of wood to elieve tension then recalibrate z stop till I get parts from NL. I did notice the blue LED intermittently flashing and I did have a MINTEMP error whichI thought I fixed so I'll include a pic of my strain relief too...

[SandervG 1,521]

Hi Ken,

Thank you for your post.

You were right with fixing the pulley when you were printing sideways.

Except when you are not printing you should not let your printhead stay at a high temperature.

It will either burn your material or the PLA inside will drip out, and your nozzle will be empty. Resulting in an underextruded first layer on your next print.

The PEEK can not melt at 250º but since you also detected the blue led to flash that was the cause.

This means it had a loose connection to the amplifier circuit board / thermocouple transmitter and at a certain point lost connection. It could no longer tell what temperature your printhead was and it kept on heating. Hence; a melted PEEK.

The connection could have been easily fixed by re-inserting the signal cable in this amplifier circuit board.

if the PEEK melted that can not be repaired, you would be best off buying a new one and perhaps a new brass pipe as well if this got stuck.