how improve top surface ?

[edit-mesh 1]

i am printing something with 50% infill

0.1 layer, 0.8 shell ,30 mm/sec and infill,50mm/sec,

wondering why the top gets so "squished"?

ok i saw that i accidently had the bottom/top thickness set to 0.5 but are there

any other points to look after to avoid this rough top surface

(already set the top surface speed to 20 mm/sec.) ???

[DidierKlein 690]

This happens because the previous layers don't have enough time to cool down, so they melt.

Two possibilities for this kind of print

1. Enable Cool Head left in expert settings, this will make the head move away from the print a couple of seconds to let the last printed layer cool down enough.

Downside: A lot of stringing and possible blobs because of the many movements of the head (and oozing due to the wait).

2. Print several at once, this will let the layers cool down enough and you'll get a better finish. You can also print a small tower from the same height next to it (if you don't need more than one and don't want to loose to much filament).

Downside: this uses more material than needed

Keep the print temp as low as possible and increase the travel speed to 200 - 250mm/s to avoid stringing

[edit-mesh 1]

hello didier

thank you very much for the 2 solutions! since i don't have achieved any good surface results in printing many pieces at once yet, i tried the cool head option, well some stringing is occuring, but this is easier to remove than to adjust the melted top.

i am missing the temperature option for the UM2 in cura :*(...

[ultiarjan 1,145]

You actually can use your UM2 in a way that you set the temp in CURA. You need to change the Gcode flavour in machine setting to Reprap(marlin/sprinter) i.s.o. UltiGcode.

This will override the UM2 firmware settings, to get the UM2 startup behaviour with the nozzle priming at start you have to add a start code in CURA, I use something like this (because of my special setup I start in the front/middle of the bed but you probably want to change that to the front left corner...)

To be honest I don't think it's worth the trouble for regular UM2 use ... you'll probably get used to selecting material/temp in the printer.

G28 ; home all axes

G1 X110 Y45 F3000 ; bring extruder to the front

G92 E0 ; zero the extruded length

G1 Z30 ; lower

G1 E50 F225 ; purge nozzle with 50mm of filament

G1 X80 Y60 F3000 ; move to the side a bit

G92 E0 ; zero the extruded length again

[gr5 1,179]

Or ignore ultiarjan and just set the temp on your UM2. You can either do it after the print starts printing in the TUNE menu or you can go to material settings on the UM2 and create a custom change, set the new temp, save it, and select PLA after choosing the save option (that's not an obvious step!).

[edit-mesh 1]

hey thank you guys!!!

well, i think its useful for me to have as much information as possible in a good working print file and i am lazy- sorry gr5 ;-)...

ultiarjan, its a good exercise for me to learn gcoding!

while trying to print a file from slicer i almost damaged my nozzle because it started right on the heated bed lever-so theres a serious need for me to use a proper start code- i will experiment with yours thank you for sharing !!!