printing quality after un clogging still very poor

[londinium-slings 0]

Hello (newbie post)

Have had my UM2 for not even a week and after the usual trial an errors started to make some nice prints, nothing special just trials such as hollow tubes, chess pieces to get the hang of things. Then I ran an overnight dodecahedron (17h hours), first 100 layers seemed to be fine, but next morning the "head was moving in thin air" .. nozzle clogged and the last couple of layers were having "gaps" .. sorry no picture availbale.

I then cleaned and unclogged the whole nozzle, taken apart, heated it up using a small creme brulee torch ;-) ... it does clean out all the gunk very nicely.

Even with the nozzle very clean again, none of my prints seems to be as nice as before .. I think I damaged the nozzle ... all prints were done at .06 mm and I only ran the fan after layer 100 or so at 10% ... tried a lot of different settings but me thinks I damaged my nozzle too much ?!

First couple of layers seem to be reasonable when I use PLA at 230, but ABS I can not get fixed anymore ... also tightend the feeder button (little white marker on the rear)

Images to follow show rook smooth printed in ABS before nozzle issue and in PLA after nozzle issue at 230 ... some attempt in same ABS again at 260 fails also.

 

[londinium-slings 0]

figured out why my gallery picture were not showing up (my bad) .. here are the results .. what I did so far ;

Bought an Ultimaker 2 last weekend. Have been playing with this ever since Sunday 15th. After the usuals trial and errors started to succeed in printing some easy models. A 10mmx10mmx20mm hollow tube in (yellow) ABS and a rook from ABS. Some smaller cylinders in PLA all to a satisfactory result.

Then I started to to a dodecahedron (17h print overnight) , previous attempts failed since I did these without support, decided to do a 10cm large model in ABS with grid support. The first layers went fine and I left it running overnight.

Next morning (after around 7h of print from the total 17h), the nozzle was in “free air” about 5cm from the last printed position and no filament was exiting the nozzle. you can see form the picture it already had printing issues long before that point. I aborted the print, and read on-line instructions on how to clean the nozzle.

I cleaned the nozzle by taking it totally apart and heat up the brass block using a “creme brûlée” burning making all the gunk evaporate.. it was truly very clean and unblocked , prior to this I only heated up the nozzle and tried to unblock with the thin wired from a transistor.

After assembling all back together again I ran another print but all seem to fail. in ABS it fails from almost the first couple of layers, with PLA it appears to happened after 100 layers or so. I did up them temp on PLA to 230 the second time, but still no result.

Taking the nozzle apart again and (re)cleaning this .. I took a macro picture of the nozzle and see it has been damaged. It’s hard to believe this was only by using a transistor needle, but still confused about the damage.

At this moment I have started a print all over again thinking maybe t’s the filament that get’s stuck on the roll and now layer down the roll and keep a close eye on the filament not begin blocked.

This print however is already startng to show "grainy" look .. the filament roll is now horizontal and there is no blocking into the extruder, I moved the print speed down from 100% to 80% and the material flow up from 100% to 107% , but no change ..

 

[SandervG 1,521]

What temperature are you printing?

Could you increase it to 230ºC and see how that affects your print?

 

[londinium-slings 0]

just did .. moved up from 220c to 230c ... will give you live coverage after a while showing results

 

[londinium-slings 0]

results ;

at 220c

at 230

 

[SandervG 1,521]

Have you already tried the Atomic Method?

 

[londinium-slings 0]

I am now getting slight improvement (but not really smooth yet) by setting the retraction length down to 2.5mm and speed down to 30mm/s

 

[londinium-slings 0]

not used Atomic method before in any of the prints but willing to give it shot, can't find it in the Cura expert settings.. whereabout is it ?

 

[Dim3nsioneer 557]

I just had the first clog on my UM2. And I followed gr5's instructions for the atomic method http://umforum.ultimaker.com/index.php?/topic/4118-blocked-nozzle/?p=33691. It worked perfectly! Thanks gr5! :cool:

My UM2 works again like a charm... until the next clog. :eek:

edit:

On the left: first result of the atomic method; on the right: to make sure, nothing is really left inside the nozzle, the atomic method was used again.

 

[gr5 2,172]

Londinium you appear to have possibly two issues.

Your nozzle tip appears to have a crater in it. It should be more flat. You might want to try grinding it down a little. This crater may harm the quality of your prints. Or it might not. I don't see any evidence that it is causing problems with that blue rook piece.

The badness in the blue rook piece is underextrusion which can have many causes. I would agree with the others and try the atomic bob cleaning method but then I would print this test piece at 230C to quantify any issues. Also put the filament on the floor instead of the back of the machine - that may seem silly but the angle it enters the feeder (around 45 degrees) is a problem - putting it on the floor makes the filament enter more vertically. Anyway try this test:

http://umforum.ultimaker.com/index.php?/topic/4586-can-your-um2-printer-achieve-10mm3s-test-it-here/

 

[gr5 2,172]

Also if you still are experiencing problems with the rook piece after the above test, please remember to post layer height, print speed and printing temperature.

 

[londinium-slings 0]

thx gr5, yes I should have been more clear and not assume anything .. layer height for all prints was 0.06, I did mention the temp (albeit not from the start of the thread) used 220 and increased to 230, speed was 100% and lowered to 80% .. for the last part of the rook I changed the retraction down to 2.5mm length and 30mm sec and after 10 min even further down to 1,5mm and 20mm/sec .. all to no availl.

The final pictures show that the flat fill(s) are good quality and the vertical side are c*p ... I will try the atomic cleaning method, but I think the "crater issue" is more the root cause of all this. Given the fact a new nozzle is about 50.- £ I'll whip out the dremel first before cleaning ...

thx everyone for your feedback ...

 

[illuminarti 18]

The poor sides on that rook piece are due to retraction not working right (probably because you lowered the distance), and also a lack of cooling when printing all of those tiny pieces. You need to set a longer minimum layer time, and maybe print multiple pieces at once so that there's more time for cooling between layers.

Also, you might find you get better results with thicker layers. I rarely find a need to go below 0.1mm on the Ultimaker².

 

[londinium-slings 0]

more good tips , thank you illuminati. I have been trying to keep "true" to the settings when it all worked fine, as with the "red rook" .. granted this was ABS and the "blue rook" is PLA, but I have some issue with ABS since the "blockage" ..

In the mean time I have "un-cratered" my nozzle as per gr5's tip. Let's see how that goes and I will use your tips also.

 

[londinium-slings 0]

result after a (very careful) dremel session, might not look much but sure as hell is better than the "cratered" one .. runnign print now ....

 

[gr5 2,172]

1) You really need the area around the hole perfectly flat or you will get very ugly prints.

2) The stringing near the crenelations of the rook is caused by not enough retraction (not too much). When it is printing that tops of the rooks look at the filament in the tube. It needs to be at the top of the tube (at the top of the arc of the bowden) when printing and at the bottom when "retracted". You can change the retraction distance on the fly.

Pull up and down on the bowden tube at the print head when not printing. If it doesn't move at all then 4.5mm should be perfect retraction distance. For every mm it moves up and down add 1mm to the retraction distance. So for example when my printer was new I had retraction at 5.5mm and that was about right but now the tube is tight and doesn't move and I have retraction at 4.5mm which works perfectly now.

 

[gr5 2,172]

To dial this in, consider printing *only* the top of the rook. On advanced tab under "quality" you can sink the rook down into the build plate until only the top few mm will print.