surface blisters with concentric infilk

[zakkus]

I like concentric infill, make for a pretty effect. However i am pretty consistently getting an uneven, blistered surface along the "seams" when i use it (see photo).

Anyone knwo how to deal with this? i suspect some sort of speed/retraction/temperature shenanigans (though i guess nearly everything revolves around those settings..)

[TenKOhms]

I have yet to use the concentric infill, but it looks like you should either increase the infill percentage or add a couple more top solid layers

[inhouse]

I think it has something to do with little uneven bumps that occur in the same place in every layer. This will then add up to a big bump.

try making a rectilinear layer in between with 25% infill, any unevenness will be pressed downwards in between the mesh.

I also learned this way that 100% infill is a bad idea...

good luck!

[ashleywebster]

Reduce the flow multiplier. Depending how many tight corners there are in the shape of your object, you may need to set up a new process for the top layer so that you can reduce the flow more than normal.

[zakkus]

i noticed the blistering will occur even on the first layer that goes down (though you dont normally notice, since that layer will be on the inside). Since this doesn't happen with the rectilinear, im thinking it might be a heat build up issue (since concentric passses the same area over and over, unlike rectilinear). Ill fiddle with the cooling and see what happens

[zakkus]

i fiddled with a few values, but nothigng really helped too much (though dramatically lowering the maximum printg speed helped moderately). Anyone else have insight into this?

[theintrospective]

Slow the print speed for that layer by at least 25%, as well as drop the temp by 5 to 10 degrees. Make sure your hot-end fans are on full.

Whenever I do concentric surfaces, I usually do 50% print speed for the top layer, a 10% drop in temp, and have solid linear fill for two to three layers below, and seldom have issues.

-Dirk R