What is the problem here?

[mamo 0]

Hi,

 

Below the picture shows my finished print on my Ender 3.

The problem is, that most of the squares have a damaged, misformed toplayer.

The top layers should be flat, like some of the other squares are,

 

What can be the problem here, I calibrated my print bed, but I think in the middle some of the areas of the print bed are not really leveled as the areas on the sides. Perhaps a warped print bed?

Can that cause top layer problems shown on the picture below?

 

What can I do besides buy a glass print bed?

 

Thank you.

Regards,

Martijn.

 

[Smithy 1,146]

I cannot say much, because I don't know how this object should look like, but the Ender 3 is known that the bed can be warped and that the printer has a serious problem with under extrusion, because of the feeder design.

Edited November 27, 2018 by Smithy
typos

[mamo 0]

Quote

11 minutes ago, Smithy said:

I don't know how this object should look like

 

 

Thanks for your reply, some of the square tiles look as they should, flat and smooth.

The majority of the tiles however have 'frayed' top layer, this is not how I intended it.

 

 

[Smithy 1,146]

I think it is under extrusion. You can search the internet about modifications you can print for the Ender 3. A friend of mine bought the same printer and has similar issues with under extrusion.

[yellowshark 153]

If the areas on the sides are level then the print bed will need to be warped for the inner section not to be level. Take a straight edge, metal ruler?, and gently wipe it across the bed; you will see if it is warped.

 

Bed levelling only affects the first few layers, something many beginners do not realise,  i.e. the first layer but if that produces some ridges or troughs then it may take 2 or 3 layers to smooth them out; really by layer 3 you should be looking at a flat surface. However your print looks very thin, so maybe. What is the Z height? What layer height are you using?

[mamo 0]

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49 minutes ago, yellowshark said:

What is the Z height? What layer height are you using?

 

 

The height is 0,6 mm and they layer height is extra fine in cura .06 mm.

It has 8 layers in total.

[yellowshark 153]

OK well I would say that with a height as low as 0.6mm then problems with a bed, such as uneven spread of the adhesive material could easily show on the top layer, especially with such thin  layers that only compound the problem*. I am not saying that that is causing what you are seeing, it looks random and spread all over the print area which is a bit confusing. It would be interesting to see the result if you set the height to 1.2mm and printed 4x0.3 layers. 

 

* as an example if you are printing 20% infill and 0.3 layers and specify 3 top layers you will just about get a smooth top layer. If you print 0.1 layers and specify 9 top layers you will not get a clean top layer. The thinner you go you need additional thickness to get a smooth top because the individual thinner layers are not good at covering the infill and transfer unevenness up to the next layer which all builds up and you need more thickness to cover it all.

 

[geert_2 558]

Hard to see in the photos. In addition to underextrusion, filament that is too wet might also cause a rough surface.

 

If you make a test cube of 15mm x 15mm x 15mm, 100% filled, same temp and speed, does that come out well? If the cause would be a bed leveling problem, it should be smoothed out after max. 1mm height.

 

[mamo 0]

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15 hours ago, yellowshark said:

It would be interesting to see the result if you set the height to 1.2mm and printed 4x0.3 layers. 

 

 

Quote

15 hours ago, yellowshark said:

s an example if you are printing 20% infill and 0.3 layers and specify 3 top layers you will just about get a smooth top layer

 

 

Hi,

 

I did as you said, a printheight of 1.2mm with 4x 0.3 mm layers and 20% infill and 3 top layers.

 

 

As I was watching I noticed that in layers 1 and 2 there was no adhesion to the printbed at certain points. Do you call this underextrusion?

 

 

As of layers 3 and 4, everything was printed normally.

 

 

I made some pictures of top and bottom.

 

I'm priming the print right now, end result will be shown soon!

 

Thanks.

[Smithy 1,146]

7 hours ago, mamo said:

As I was watching I noticed that in layers 1 and 2 there was no adhesion to the printbed at certain points. Do you call this underextrusion?

 

No, I still guess your print bed is not plain. Please check it with a ruler to be sure. 

 

Or your bed is not leveled correctly. The Ender has 4 screws to level the bed if I am right, which is not so optimal and much harder to level, so take your time to level it perfectly. Do it at different positions on your bed and recheck the positions again after the first round.

[yellowshark 153]

@Smithy is right it is not under-extrusion, well unlikely anyway. Also I am not convinced either that it is bed levelling - although a non level bed will do you no favours. Your first pic shows it to be seemingly random; if your bed is not level say on the x axis then if the left side of the bed sticks OK by the time you get over the the right side it may not be sticking, or the bed is so close to the nozzle on the right side no filament can get out. The point is that as you move from left to right the stickiness will progressively get worse or get better.

 

I suspect you have one of several problems...

Your bed is totally knackered - as @smithy and I have both said run a straight edge over the bed to  see if it is OK.

You have a build up of adhesive - no idea what if anything you are using - clean the bed thoroughly and retry

Your bed to nozzle distance is incorrect, too small or too large; I suspect it may be too large, try to set the bed up so the filament is really squished down; you can do this in real time although probably a bit trickier with 4 screws rather than 3.

Your bed heater may not be very efficient; i.e. and e.g. whilst the centre of your bed may be at the correct temp., the peripheral areas of your print area my not be - wait longer (10-15 mins) to ensure the bed is all at the same temp desired temp. Better still measure areas of the bed with an IR temp gun

 

I think it will help us if you print a 1*0.3 layer and send us a photo

[mamo 0]

Thanks for your help, I used the thin paper between nozzle and bed method, by adjusting the 4 screws under the bed to level the bed.

When I make the bed level on all sides, in the middle there is noticably more of a gap between the bed/paper/nozzle.

When I make the bed level in the middle, the nozzle scratches the bed on all sides of the bed in a way I do not like it, and think it will damage the bed as well as th nozzle.

 

So I i guess my bed is warped.

 

I made a 1x0.3 layer print : 

 

 

 

It looks ok, except from the strange line on the left side of the square?

And the diagonal lines are not melted together, they are all loose strings like a gitar.

 

Perhaps that has something to do with the temperature, I lowered it to 190 degrees, to solve another problem.

 

 

Edited November 29, 2018 by mamo

[Smithy 1,146]

The Ender 3 is known to have warped beds, but if it is not too much it should work anyway.

 

Too low temperature causes under extrusion because not enough material will be extruded. so raise the temperature again to 195 or 200 and try again. You have to find your optimal settings for temperature, layer height and print speed. Changing one of these parameters directly reflects the amount of extruded material.  But normally with not extreme print settings, the default values work quite well.

 

I assume all other settings are the default settings, so you haven't changed line width or something like that, which could cause a similar picture.

 

 

[mamo 0]

4 minutes ago, Smithy said:

You have to find your optimal settings for temperature, layer height and print speed. Changing one of these parameters directly reflects the amount of extruded material

 

Most of my settings are default, yes, but I'll try and experiment more.

For now I primed the tiles and used some putty, and 2 paint coats later it looks more as a tile terrace.

 

I ordered a borosilicate glass plate for my Ender and a metal extruder upgrade, which according to users should improve print quality.

 

Thanks again for the help!

[Smithy 1,146]

40 minutes ago, mamo said:

I ordered a borosilicate glass plate for my Ender and a metal extruder upgrade, which according to users should improve print quality.

 

Both a good investment and you will see with a reliable extruder your prints will get much better.