3D print top layer - gaps

[tvel]

Hello!

I’m fairly new to 3D printing and I’m having a bit of trouble. My 3D prints have irregular gaps in between the filament on the top layers-- the rest of the print looks great but that top layer ends up looking pretty spotty with the gaps. Please see attached picture and cura settings. Any suggestions on how I can make my top layer smoother?
Thank you for your help! Excellent community, happy to be on board.

[Perry_1]

Under extrusion. The reason your print looks good on the side is that the filament is squishing well on the walls. Since this does not happen on the top, you can see your obvious under extrusion. Measure your filament, if you have a place to enter that into your slicer. You may need to increase your extrusion width or mess with your extrusion multiplier.

There are two other options to try: More top layers. It is possible that the filament is sagging into lower layers, you may need a few extras layers to get to solid on top. More infill %, can also solve this, so you have less sag on top.

But really, I am pretty sure you are underextruding, as your speeds look good to me.

[tvel]

Hi Perry_1,

Thank you for the help!! This sounds great-- I will adjust and play around with some of the settings you suggested tonight. I’ll let you know how things turn out-- thanks again!

[Asad3D]

What printer do you have @tvel?

[tvel]

I have the Monoprice Maker Select (Wanhao Duplicator i3 clone).

[conorm125]

It may also be a slightly clogged extruder

[tvel]

So I went ahead and replaced my nozzle with a Micro Swiss one and I purchased a caliper and checked on my filament-- once or twice it dipped into 1.74 but I checked about 9-10 places and it seemed to be 1.75 down most of it. I ran another print last and ended up with about the same result as the first time I ran it. That top layer still seems to have slight separation between lines of filament. Are there any settings in Cura that I could experiment with or any other thoughts as to what I might be doing wrong? Thanks again for any help!

[conorm125]

Is there a extrusion multiplier option in cura as it could just be the gcode not pushing enough plastic. I use s3d and have had gaps which was fixed by increasing the extrusion multiplier

[Perry_1]

OK, I think Cura the “Flow Rate %” is the extrusion multiplier. I am no expert on Cura, I use simplify3d.

[tvel]

Thank you! I raised the “Flow Rate %” to 110% and started the print-- it does look better! The back end still has some separation but there is a very noticeable difference between this and my last few prints. I attached the front and back pic from the recent pic. I will raise it a bit more and see how things turn out.

[tvel]

Thanks so much for all the help thus far. I’ve been trying different solutions you all have mentioned-- including trying a higher extrusion % (110 then 115), more top layers, a higher infill % and measuring my filament to make sure it is the correct size. I’ve adjusted my settings a few times – I’ve attached what I am at right now. As it stands, I am getting much better prints with these settings-- the gaps are not nearly as bad but they are still present. My top layer has a smooth feel to it but you can tell there are strands lined up and in a few places there are still some gaps. See the enclosed pictures. Would you guys recommend making any alterations to my current settings to improve my current prints? Thank you again for all the help. These are good lessons and I’m learning a lot as I experiment.

[Perry_1]

OK, looking at your print, I think you should lower your print speed during printing.

When your printer starts out the fill on the top, looks like you have plenty of plastic when it starts to extrude. Then, it gets thin as it accelerates, then is thick again when it decelerates into the end of the print line.

I am guessing here, but that would imply that when your printer is printing at maximum speed, your extruder is having trouble keeping up.

90mms is fast for a monoprice, at least until you get it dialed in. I would move more towards half that for now.