Gaps in print

[donnyfl 1]

Hey guys, printer was working fine for the longest time then all of sudden, my prints seems to have gaps in the material even when come out of the extruder.

I took the material out, cleaned the nozzle to make sure there's nothing preventing the flow. Changed the material and still same results.

Any direction would be appreciated, thanks!

Notice the holes in the outer ring

I also tried adjusting the tension on the feeder, same results.

[skinny-kid 65]

How many hours have you been printing? Have you checked the integrity of the PTFE coupler?

It only lasts for a limited amount of time before deforming and causing issues with filament getting fed through properly. I have replaced mine a few times already (my machine has over 1500 hours on it so far) and after I replace it the machine runs like a dream again.

This link will instruct you you how to do it.

http://support.3dverkstan.se/article/56-replacing-the-ptfe-coupler

Let us know how it goes and if this remedies your issue.

[donnyfl 1]

Thanks Skinny, I decided to take apart my hot end and everything was going well until I had to yank out the temperature sensor. I've printed less than two rolls of filament. When I saw the hot end unit, I have a good feeling now I know why my prints are the way they are. Looks like my printer sharted itself.

Now the fun part of trying to figure out how to take apart the UM2 to replace the white temperature wire. Ordered about $130+ worth of replacement parts from fbrc8. My rear fan has always made a weird noise so ordered one of those to see if it suppose to make that noise or not.

I've only printed with PLA so far, so would think it would have lasted longer.

[skinny-kid 65]

Ugh sorry to hear about the headaches. By the looks of it your PTFE coupler was toast. Not sure if you needed to pull the whole apart (the temp sensor and heating cord are a PITA to get out of the original block unfortunately) but since you have I highly recommend purchasing the Olson block for your UM2. It makes nozzle switching a breeze and has a much better method of keeping the temp sensor and heater cord in place. I have almost no headaches since installing it except going through PTFE and Duptef couplers....lol

Good luck man....let us know how it goes.

Edited June 8, 2015 by Guest

[DidierKlein 729]

@donnyfl

If i understand well you have not printed a lot with your Ultimaker 2? I have changed my whole head a while ago on mine, but it had printed around 800 hours, and it wasn't even close to what yours looks like.

I really have the feeling that something is (or was) wrong with yours. It almost looks burned. And it shouldn't. Have you contacted Simon at fbrc8?

[IRobertI 520]

The burned parts looks like PLA back flow. Look at the PT100 wire, it's caked in plastic.

[donnyfl 1]

Thanks guys, I've had the unit for less than 3 months and don't think I've reached the 100 hr mark yet. I've been using Matterhacker's PLA but when I took off the heat shield, there's a build up of the grey PLA that came with the unit. This must've happened a while ago because I haven't used that color.

There's not much info out there on how to take this UM2 apart. After a few hours I was able to take off the motherboard cover to reveal the heat sensor wires. Ideally I would like to yank off the whole black cord that wraps all of the wires for the head but that would mean taking out the motherboard to disconnect the blue and orange wires which are connected on the top. So My workaround this will be to tape the new PT100 wire to the old one from the bottomand pull it out from the top.

I am going to email Simon and see if he has any idea why this burnt out so quickly.

Edited June 8, 2015 by Guest

[donnyfl 1]

Received my Olssen block today and was excited to get it installed. My first test ring went well however, when it was printing the second one, the quality looked like crap again.

I am in the process of taking the whole block apart again and noticed that there are a lot of filament on the threads of the nozzle, is that normal?

I cleaned it up a little before taking this picture but you can see traces of it still.

I checked the step motor pullies and they are still tight. I also ordered OEM nozzles from fbr8 and they also arrived today. Tempted to put those on but will give Olssen block another try. Heard really good stuff about it.

[ultiarjan 1,223]

Don't give up. I'm running it without any problems for a long time now. make sure you heat the block before you tighten the nozzle. And did you print the wrench (best in pla) tool? If not I would advice to still do it.

[swordriff 119]

Plastic on threading happens when not tight nozzle,

Like @ultiarjan says, only screw it when hot!

So to re-attach, move material (head is now hot) then slowly insert

Dirty nozzle .. It will get hot, plastic melt and the screw in.

Tighten with Torque Wrench in PLA (exactly!) until wrench skips.

Print happily away...

[ultiarjan 1,223]

and here the link to be complete:

https://www.youmagine.com/designs/nozzle-torque-wrench

Edited June 13, 2015 by Guest

[swordriff 119]

Thanks Ultiarjan. Last thing: do not leave the Wrench and pipe connected to the hot nozzle more than 10 secs, as the heat transfers through the pipe and weakens he wrench..

Always change nozzle at hot temperature, else anything can happen.

I guess what happened to you is that you just did not tighten the nozzle.

This is not a general problem. I have heard about 1 leak before, and there are now many hundred of these nozzles & blocks out there.

Thanks !

Edited June 14, 2015 by gr5