PLA Ripples

[Dana 2]

Hi All, I have had the issue below with two attempts at the same print in exactly the same place, is this a print bed heating issue, levelling issue or adhesion problem? I am using pritt-stick glue that was supplied with the Ultimaker 2+ and all i do is put it on then even it out with a wet sponge, normally this give be excellent results

I have not printed to this corner of the bed before so I hope its not a heating element problem

many thanks in advance for your help

.4mm Nozzle, profile set to Ultimaker PLA

[Dana 2]

oh and what do you think is causing these lines in the last image?

[Dana 2]

looking under a jewellers glass I can see that in the bottom picture on the bed face the extruded lines seem to cross over, its like the extruder is jumping sideways slightly and the layer is splitting into two, one side is higher than the other. then over the next 10mm it merges back into one layer, this happens on every line, very odd.

for the top pictures the extruded material seems more rounded underneath which I presume is a levelling issue? i.e. not pushing the first layer into the bed enough? is a very very small difference

Edited November 27, 2016 by Guest

[limburgmetaal 9]

have you tried to make the same print with an other slicing program as well

cura and s3d? if so this will eliminate the error in a Gcode

[Dana 2]

thanks for your reply, I don't have any other slicer, perhaps I should try that

I am new to this so was trying to keep life simple

[limburgmetaal 9]

I have both cura and s3d, if i can help than let me know

[neotko 1,417]

In my experience tidal waves always means that the nozzle is too close to the print. So tinny waves, tiny bit too close to the bed. When the nozzle is too close if the first layer speed is fast (or just not way too slow) the nozzle passes over the print area pulling up some of the printed parts, making small tidal waves.

Readjust a little tiny bit the screws under the bed so the nozzle is a bit more away from the print.

[Dana 2]

ok will try that thanks.

thanks for your reply "Tidal Waves" is a good description of the problem, I googled that and didn't find anything so you probably just invented a new phrase/description

just wanted to add that the two times I tried this print were with completely new designs but same dimensions and orientation on the bed

the second time I really made sure that there was the same about of glue over the print area

so it must only be one of the following surely

Bed heating

Bed level

alignment of the nozzle, drive chain etc

I didn't have this before, the only thing that I have changed is new cura and firmware

Edited November 27, 2016 by Guest

[gr5 1,999]

How thick is your bottom layer? 0.3mm? That's the default - just checking.

It's probably not the temperature of the glass. More likely the glass is either not quite level or not quite flat. Or your gantry isn't flat. Glass can be warped and can be corrected by inserting a thin shim such as a washer or a few pieces of paper in the "low" corner(s). But usually the glass is warped less than the first layer thickness. Still this seems quite possible.

Try putting a metal straight edge on your glass in various angles to see if that corner is low/high. It could still be the gantry above. The 4 rods in the outer edges of the printer might not all be in the same plane. Especially if your printer was shipped using DHL which apparently hires elephants to stand on the corner of each package as part of some critical shipping process. But all shippers seem to use the elephants occasionally. Does your printer sit flat on the table or does it rock?

[Dana 2]

so I seem to have resolved the problem but I do not know the cause, I didn't follow my own rule of fault finding i.e. do one thing at a time. instead I reset the bed (actually I think its still too close but it worked) I also reorientated the piece on the bed avoiding the top left corner, I put a little oil on the rails.

So it worked but if I have the issue again I will not know how to resolve it in one step, not great for tuning

here are the results, the white one is a PoC which didn't actually work. it has magnets in the back but it wouldn't hold bigger knives so I added two slots to the copper fill versions and halved the word thickness

I covered the copper fill in salt and vinegar over night and gave it a quick polish, there is a bit more finishing to do

thanks for all your advice and suggestions

Edited December 4, 2016 by Guest

[gr5 1,999]

You never answered the question about how thick your bottom layer was in cura.

[Dana 2]

I believe it was .8mm as I was using standard PLA settings on fast and light fill