under estimated print time / print quality

[jimc]

the holes in the surface can be from too high a temp combined with too low of an infill. the plastic gets too soft and gooey and breaks apart during the infill process. also what helps is to be sure you turn the "random infill placement" off. also under extrusion and too low a temp as oldward said can be a cause.

[vOidward]

the holes in the surface can be from too high a temp combined with too low of an infill. the plastic gets too soft and gooey and breaks apart during the infill process. also what helps is to be sure you turn the "random infill placement" off. also under extrusion and too low a temp as oldward said can be a cause.

There isn't a reason for that to happen if he's extruding at 220 with the filament fan on. The settings have 4 bottom+top layers.
His prints also look like they're peeling apart between the first and 2nd layer. There's no way he's getting layer separation like that from temps that are too high.

[TenKOhms]

Ill never understand how makerbot can extrude PLA nicely at ~220-230 C. I always print PLA at 185-190. Possibly low extrusion multiplier then in his case. Also, I think measuring the diameter of filament is an underrated factor, as more often than not, my filament is a bit smaller than promised on the packaging. I print with 3mm filament (usually have to set my it to 2.89) though, so I'm not sure how 1.75mm usually comes.

[jimc]

tenk, its really not that the plastic is being printed at a different temp than you. its all in the hot end and where the thermistor picks up the temp. the original hot end in my makergear took the reading on the nozzle which would extrude at the same temps as you. newer block style hot ends pick it up in the block usually close to the heater causing the temp to read higher than it actually is at the nozzle.

[MasterFX]

printed the donuts using your files and a key widget but having problems with the finish at the top layer =(

I observed the same problem... but only when using concentric infill. I was able to prevent this problem by only using one layer of concetric infill and the other infill layers are set to rectilinear.

Use two or three profiles:
1. a profile with concentric infill and 0.2mm "stop printing height",
2. a profile with rectilinear infill from "start printing height" of 0.2mm to "stop printing height" with model-height - 0.2mm
3. a profile with concentric infill "start printing height" with model-height - 0.2mm

[paeonius]

thanks for your suggestion guys, i solved the problem by bumping up the settings of the top layer 6-8 usually did the trick