Rumbling sound over previous layer?

[LePaul 321]

I had a few evenings of good prints but the last two have failed

Last night, same file/gcode, I kept hearing a 'rumbling' like sound as the print head passed over the previous layer. I know the bed calibration is spot on. I do have Coasting on and the model uses a lot of support material.

Any tips on what that could be?

Ultimaker 2+

Cura 2.3.0

Thanks!

[Torgeir 242]

Hi LePaul,

I'll think this is the nozzle hitting the infill when retracting over here. (Yes I have same things happen on some prints).

There is a setting in Cura, see the "Preferences" and go to settings, find "Travel" and cross out "Avoid printed parts".

I have not tried out this in Cura, but it does work in S3D.

OK.

Good luck.

Torgeir.

[LePaul 321]

Thanks I'll hunt for that in Cura 2.3.0

[Snipper 0]

Hello,

When I print Polymax (sort of HQ PLA) I have no problems (even with Nozzle 0.25, layer thickness 0.04, 100% infill), but when printing Innofil PLA with the same settings I also get that rumbling of the buildplate, as if the Filament does not flow out enough... and on top it shows like (micro) Emmenthaler cheese.

Maybe (I will try) reducing the flow or the 100% infill? or temp?

Also U 2+ Cura 2.3.0

Searching for other solutions...

[Snipper 0]

Thanks I'll hunt for that in Cura 2.3.0

 

Hello,

"Avoid printed parts" is NO solution against rumble!

This is only ment to avoid other parts when there are more parts on the build plate.

The "avoid..." action is a "Z hop" if neccecary during x-y movement from one to another part.

[owen 19]

I get a rattleling sound as well. Do you you think it could be from combing?

[LePaul 321]

Phew, it isn't just me

Maybe @nallath has some ideas

[nallath 1,120]

As far as I know this is usually caused by material being pushed upwards (warping / overextruding) that creates ridges. When the nozzle passes them, it makes a rumbling sound. Decreasing the speed helps, as does increasing nozzle temp (you pretty much start doing the neo-sanding thing at that point).

[LePaul 321]

Okay, well a few thoughts...

I can't seem to change the temp in Cura I have been trying to let the newer, smarter Cura choose all the proper settings, changing only the infill, thickness of walls/top-bottom and support.

I can certainly lower the speed a bit.

[gr5 2,172]

Isn't temperature on the machine?  Not in Cura?  For UM2?  I haven't used cura 2.3 with Um2 yet.  Only um3.

Anyway I get the rumbling.  The dreaded rumbling.  Sometimes.  Usually in the areas of overhangs - like if you are printing a BB-8 sphere then you will get it low down where overhang is the worst.  On overhangs you get something I call "raised edges".  The best fix for raised edges is more fan but I assume you are already at 100% fan.  Another fix is more support - add support when it is worse than 45 degrees can kind of hold things down and reduce the "raised edges" effect.

But the best solution is to get your part to stick like hell and just live with it.  That's what I do.  And we've discussed this before but the main thing people don't do is squish it enough into the tape or glass.  If you squish it so much that it's transparent it will stick so damn well it will occasionally (once every 200 prints) remove tiny chunks of glass when you take the print off.  People just don't realize the power of "squish".

[LePaul 321]

Hi @gr5

Yes..100% fan. Support is already enabled

Using glue stick too.

The support is sticking to the bottom...it's as it builds it up something is getting knocked loose (perhaps from the rumbling)

[neotko 1,417]

You could tru a small 0.2-0.6 z hop on retraction moves to avoid hitting the parts.

[LePaul 321]

I'm using nGen filament for a print tonight and have noted some rumbling early on. I have upped the temperature 2C and slowed the printer down to 95% (50 mm/sec)...we'll see how that goes.

[LePaul 321]

Well it happened again

It shouldn't be knocking the support material down! Especially nGen! I mean, between gluestick and 85C, that's quite a bit of force to break that off.

Could Coasting be doing this?

I wanted you to see how the print goes and you see how at some point it knocks the support material around (see 35 second in)

 

[LePaul 321]

I'm going to try @neotko 's idea. It sure makes for a lot noisier printing experience Maybe this will help Here's the settings I used...

[LePaul 321]

Well this failed again.

I suspect a problem with the heated bed...I mean, what else could it be???

I'll process the time lapse...

[LePaul 321]

[LePaul 321]

A few thoughts in review...

I've been doing some research, since this is failing on multiple filaments...

Maybe I just got lucky on the first two prints that worked. The rest have all failed.

zhop helped with the rumbling but I think it boils down to the print is coming off the bed.

Should I be adding brim? The entire base of the print is support material. How much? Distance? Line count?

There's a lot of posts about the first layer being hotter than the rest. I don't see a really good way to control this in Cura 2.3.0 It looks like manually upping your print temp through the printer interface might work best.

This print uses all support material on the bottom, so something is going on down there causing the adhesion to fail.

[tinkergnome 927]

Should I be adding brim?  The entire base of the print is support material.  How much?  Distance?  Line count?

 

In this case i would use a raft (with "Air Gap" changed to 0.0).

This should result in a stable base for the supports.

[LePaul 321]

Worth a try....air gap?

[tinkergnome 927]

Worth a try....air gap?

 

[LePaul 321]

Thank you @tinkergnome

Should I change the support pattern?

[LePaul 321]

Okay, using those settings.  Looks like my 15 hour print went to 24!

[LePaul 321]

...and now 48....what's with Cura's time prediction

[gr5 2,172]

LePaul - I don't think you leveled the nozzle close enough to the glass. You need to squish it even further into the glass. Turn the 3 screws another 1/2 turn CCW.