SoliForum - 3D Printing Community — My extruder randomly cooked itself this morning....

Re: My extruder randomly cooked itself this morning....

null@example.com (IanJohnson) — Thu, 28 Feb 2013 00:24:49 +0000

There is no adhesive, the inside of the PEEK is threaded. So it got hot enough the the threads melted and let the barrel slide out. I wonder if it is possible to have a short somewhere on the board that would let it heat up. The safeguards are supposed to cut the power if it overheats, but if the heating was out of control of the software, there isn't much it could have done. Does anything look odd or out of place on the electronics? The heaters connect at the bottom of the board.

When you came back, was it still hot to the touch, or according to RH? Was there anything in the log indicating overheat errors?

Re: My extruder randomly cooked itself this morning....

null@example.com (newq) — Thu, 28 Feb 2013 00:04:30 +0000

The black plastic feeder is what I mean. It might look fine from the outside but the black stuff around the brass barrel's threads looks like it's from the PEEK. It looks like the brass barrel got so hot that it was able to melt the PEEK to a point were it just slipped out. At least on my hotends the brass barrel can (should) be screwed into the PEEK without the need for any thermal adhesive or stuff like that.

I'd wait for word from one fo the experts on this forum (I'm not one of them) but I think the PEEK is gone and needs to be replaced.

Re: My extruder randomly cooked itself this morning....

null@example.com (Aron) — Wed, 27 Feb 2013 23:51:11 +0000

newq wrote:

Wow that looks evil! This was caused by way too much heat from the hot end for sure.
You will have to replace at least the PEEK Insulator if you can clean the thread of the brass barrel and nothing else is damaged. It also looks like you will have a massive clog because the ABS at the tip looks burnt.

Yes, I think I have a massive clog too. I was scared to fiddle with the head because I feared I would gouge the metal. I can fix that with a little patience.

I assume the PEEK part you are talking about is the black plastic feeder. That appears to be completely fine, because I caught the problem very soon after it happened.

I need to figure out what kind of adhesive/resin I need in order to reattach the extruder barrel with wires to the PEEK part though.

Is this stuff called "thermal adhesive" or something at the hardware store?

Re: My extruder randomly cooked itself this morning....

null@example.com (newq) — Wed, 27 Feb 2013 23:43:04 +0000

Wow that looks evil! This was caused by way too much heat from the hot end for sure.

You will have to replace at least the PEEK Insulator if you can clean the thread of the brass barrel and nothing else is damaged. It also looks like you will have a massive clog because the ABS at the tip looks burnt.

My extruder randomly cooked itself this morning....

null@example.com (Aron) — Wed, 27 Feb 2013 23:29:51 +0000

Anyone else have this problem? I connected it to Repetier, set the bed temp to 94 C, walked away BRIEFLY, came back and discovered my extruder head had melted.

No connection problems, both temps were off, and both temps were actively reading temperatures. The bed was slightly warm.

This must be a software problem, right? I've never had it happen throughout the past 4 months during which I've owned it.

So, some of the fail safes worked, but some didn't. I am confident that I did not turn on the extruder heater (nor raise its temp). So, don't leave your 3D printer alone while it is on!!

The adhesive is what melted. Can I fix this with commonly available hardware materials???

-Aron