londinium-slings

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

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.

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 ...

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 ?

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

results ; at 220c at 230

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

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 ..

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.

G'Day, I'm afraid I tinkered with my UM2 nozzle too much while unclogging .. the .4mm gap is not as smooth anymore and all my prints seem to have awfull extrusion layers. I havebeen looking on-line but can only find the UM1 nozzle types, not the UM2 type that has the nozzel as part of the block. Even on UM2's shop web-site I can not find the right part ... cheers Jørgen