Marvin in bad conditions

[chris_nobody]

I have problems to print Marvin in ABS.

The overhang between the legs is horrible.

See the pics. I have tried bedtemps from 100-110 degrees,

Nozzletemps 220-240 degrees.Flowrate down to 70%.

Any suggestions?

[michel_vanson_5]

Did you try setting the temp even higher? 250 degrees? I haven’t tried printing ABS but did read about a very high nozzle temp…

[chris_nobody]

The problem are overhangs with angle lower than 45°.

Filament is rising up and burning on the nozzle.

[chris_nobody]

Sometimes even angles greater than 45° are not well.

See the left part on the pic.

Also changed the extruder gear to iron.

[Filemon]

Hi @chris_nobody have you been helped yet? If not, I bet @ProdPoint, @James_2, or @key23d can help you out. Cheers!

[key23d]

Hi @chris_nobody,

I also have problems with overhang sometimes but normally not with ABS.

With PLA I sometimes also get the wrinkles of filament and the only way I found to solve this is either to reduce the angle in the design or lower the temperature of the nozzle. When the filament is to hot it forms a thicker layer of filament that crawls up against the nozzle; thats wat you want to prevent.

You can see if that happens by taking a very close look at the nozzle and the filament that is put down. If you see that the filament is higher than the bottom of the nozzle your temperature is too high.

If it still happens after you lowered the temperature you might still be overextruding.

Hope that helps!

Kind regards, Guy

[key23d]

@Filemon, thanks for the tip!

[James_2]

Hi @chris_nobody - I am no ABS printer (mainly use PLA as it is easier for this kind of thing, but some of the principles are the same;

Print as cools as you can

have some cooling - I understand ABS likes a small amount of fan, but also a hot print chamber to reduce rapid cooling

print 2 marvins at once - as I think you re seeing the heat of the nozzle re-heating the layer too soon

print as fast as you can - so the dwell time is low on the nozzle/layer

I don’t think it is flow or your hobbed bolt as they look slightly under-extruded to me. and the bigger one seems to have less artefacts as the layer travel is bigger so less re-heating

Try some of the above and come back to us. - If you have not fan on the machine - run a table fan lightly across the bed - but try the two marvin trick (or a wipe tower.)

Hope this helps - also try PLA!

James

[chris_nobody]

Thx for your hints, i try it soon!

[chris_nobody]

Thx for your hints!

Kind regards, Erich

[chris_nobody]

Best result so far! Heatbed with 90°C nozzle 225°c and 80mm/sec, but when nearly 60% finished the Marvin

lost connection to the bed… grrrrhh…

Thanks a lot.

[Mitch_1]

same issue I get when printing round objects if I use any other infill patern besides honeycombed which suports walls better without pulling them in while printing or not fully conecting to walls.