What to do about delamination of layers?

[tbruggeman 0]

Hello all,

Currently I'm trying to print a very basic model of a bearing block for my CNC but I'm encountering a problem. I'm still fairly new to 3D printing and I could really use some advice from others.

When I start printing the model everything works fine; good density and layers bond well. For now these kind of results would be sufficient.

 

Unfortunately after a couple of layers it all goes wrong. Adjacent lines do not connect properly anymore (there's a gap in between), new layers do not bond with the older ones and there's a lot of stringing going on.

Does anyone know what could be causing this? What should I change to avoid this?

Any help would be greatly appreciated.

Grtz

Thomas

 

[swordriff 119]

Thomas!

For you it is probably combination of build speed and temperature..

Next likely is sticky filament, hard for printer to un-spool... Try unwinding a bit...

Can you post settings in CURA, as well as settings in UM2.?

If you print in a cold(er) room.. then the higher levels dont "inherit" the temperature from

the build bed, (assuming you have a heated bed).. and as the higher levels thus are colder because of

this, the new layers don't attach well. You can compensate somewhat for this by increasing extr temp and

lowering speed.

With a heated bed to 60, CURA speed setting of 70mm/s, and UM2 speed setting of 60% (combined speed is then

60 percent out of 70mm/s = 42mm/s, AND higher extrusion temp, try 235, and fan off,

Then we should make it stick.

These settings will incur stringing, which you work at on the next stage by lowering speed and temperature..

Temp can go down to 220-215-210-200, speed down to 50% (in UM2).

Good luck!

 

[ian 32]

heat up your ultimaker 2 and with a tiny.. less than .4mm needle, give the inside of your nozzle a quick clean out..

Then reload your PLA... print nice and slow at 50 should be fine.. then print temp 220... that just be plenty for PLA.. also you could put the flow up to 105 percent.. that helps me print with colorfabbs wooffill PLA :-)

Keep us updated on what happens !

Ian :-)

 

[gr5 2,173]

in IMG7567 it looks like you have some serious under extrusion. Check to make sure your roll of PLA isn't tangling. This is common on a new roll especially on the Ultimaker 2.

Higher temperatures give you better adhesion but I really don't think this is a temperature issue - it looks like underextrusion. This can be caused by plugs/dust, or by printing too fast, or by nozzle too cold, or defective extruder, but I'm thinking tangling is the most likely.

 

[gr5 2,173]

230C is definitely not too hot. Sometimes I print at 240C.

If you are getting *any* clicking/extruder slip back then you need to slow things down some more.

Here is a test I did with the UM2 but it is for an open nozzle - not one pressed close to a part being printed:

http://umforum.ultimaker.com/index.php?/topic/3418-um2-extrusion-rates/

Since the time I did the above testing I noticed that sometimes the extruder misses steps but without sliding back (clicking). That's harder to spot/notice/detect. It was doing it on nylon so maybe it only does the silent skip with nylon.

 

[swordriff 119]

I looked at the IMG7567 again!

I agree with gr5.. This is underextrusion... could be sticky spool, thin filament.. etc

Low temperatures will also not help you. Suggest, raising room temp to

20+, increasing nozzle temp to 230+, make layers stick first.

Then, focus on strings (which will form at 230) etc... by lowering temp and speed.

.

 

[tbruggeman 0]

Today I tried the print again and it worked!

You guys were right about the temperature and/or the spool.

I put the printer in my living room for a higher temperature and unwound the spool a bit.

The second picture shows it missed the very first lines but as soon as it started on the model the PLA began to flow nicely.

 

Here some pictures of the results:

 

The last picture shows there was one layer that didn't go well. At this point the PLA feed stopped as it was eaten out by the knurled wheel. I pushed it back and at this time I put the spool on the floor. After this everything worked perfect.

The print is really strong and I even tapped holes to secure M8 bolts.

Finally some pictures of the print on my CNC:

 

 

Thanks guys for all the help!

Next project will be some spindle brackets I guess :mrgreen:

 

 

[swordriff 119]

We are glad to help!

Now.. your placement of the spool seems risky.

OOPS:If you put your spool just on the floor, you risk:

- With every unwinding of from the spool 1 warp is introduced. This may cause

serious trouble for you in the machine, breaking of filament (esp if temp <20) etc..

Maybe you do not have space for the original holder that came with the UM2?

(BTW, this holder is also not ideal, the speel should be allowed to reside closer to

the back wall..)

The original holder will keep the spool more than less in the right place for the unwinding of

the filament. As other moderators have pointed out, it can be useful to "unwind" a bit..

but keep it inside the spool..

Your current arrangement asks for trouble... entanglements..

 

[chopmeister 0]

I keep my spools freely rolling on the floor for 2 years now. Never a single problem due to tangling, or underextrusion for that matter. Here and there I unwind it a bit, but even if I forget, it still prints fine.

The spool holder on the UM is something I got rid of some two days after I assembled my printer. It gets in the way all the time, some spools don't fit etc. Never found spool holders all that useful but YMMV.

 

[matengi 0]

I suggest this: https://www.youmagine.com/designs/broomstick-spool-holder

Works perfectly for half a year now, for all kind of spools.

 

[mr 0]

Hi guys,

hope you are all fine. I have got a problem which i do appreciate if you help me with. My frist layer of printing is delaminated from thr following layers, and i don't know how to solve it. does any one can help me with that? thanks

[ghostkeeper 105]

Only the first layer is loose then, mr? Perhaps the initial layer is shifting a bit before the second layer is applied. This could have something to do with the adhesion to the bed.

I suggest you check that the bed levelling is accurate, that the bed is secure and that the print sticks well to the bed. There is a bed levelling wizard in the printer's maintenance menu to help you with the first.

To make the print stick better to the bed, there are a couple of ways. You could apply some paper glue (such as Pritt) to the bed. These glues can easily be washed off the glass afterwards. You could put down a layer of painter's tape, to which many materials will stick better. Or you could lower the speed of the initial layer in Cura (under advanced settings, called "Bottom layer speed") and perhaps increase the initial layer line width (also under advanced settings). You could also reduce the initial layer thickness a bit.

If that is not the problem, maybe you could clarify a bit more what's happening?

[Yuviten 0]

Hey same problem here. Outermost layer peels off. Using 240 C, flow 100 per, bed temp 50 c,