ABS not sticking to build plate

[renarj 0]

I just received my Ultimaker 3 last weekend and am trying to get ABS printing to work. However I am really struggling to get it working. With PLA I have no issue whatsoever and the prints are fantastic, but ABS is really troublesome.

If I print with a Brim, the brim itself will not stick to the bed at all. When printing with a raft at least the raft will sort of stick but it starts curling rather quickly. Also after the print the raft is very loose and can easily be removed. Somehow yesterday i got one print working with a raft, however the bottom layers of the model on top of the raft started curling, all top layers where great though.

Settings tried:

Head Temperature: 230 / Build plate: 90 (this worked sort of but with curling)

Head temperature: 250 / Build plate: 80 (no sticking whatsoever)

- Tried with hairspray (works great with PLA)

- Tried with the provided glue stick

Note: Cooling is off for all settings i tried so far.

ABS Used: Performa ABS White

I am getting a bit desperate and unsure what else to try? Was really hoping that a printer in this price range would be a lot better with ABS. I am looking for tips that can make the difference here?

Edited January 31, 2017 by Guest

[gr5 2,172]

Definitely increase bed temp to 100C but your main problem is most likely that the nozzle is too far from the build plate. Try simply turning the 3 bed leveling screws 1/3 turn counter clockwise (as seen from below) and try again. If it's still not working turn another 1/3 while it's printing the first layer. Turn them equal amounts. Much more details here:

 

You will have a few other issues with ABS - most notably you will probably find that the layer bonding is weak. That is fixed by enclosing your printer or turning the fan down to about 3% (on UM3, 30% on UM2). Or both.

Many people don't notice the layer bonding issue until their 100th print when they find out how much weaker ABS is than PLA.

[renarj 0]

I started turning the bed more towards the nozzle and this seemed to do the trick first print stuck properly and completed fully. Also I started using abs juice on the glass plate, this seems to also help quite a bit.

However the second print which took a lot longer and is a lot higher started hitting the nozzle once it reached roughly 15mm. Any idea why this can be, did I move the bed up to much to the nozzle?

Find it strange i have to manually do this for an ABS print, why cant cura/ultimaker do this automatically for me.

I have also ordered some ultimaker ABS supposedly this is a lot better, will have a see tomorrow if this make a difference.

[gr5 2,172]

Turning the screws is no good if it does an autolevel after you turn the screws because it will calibrate out any correction you made.

Parts that hit the nozzle are caused by outer overhangs - like the bow of a boat. Or really any kind of overhang - any wall that isn't vertical. The cure is 100% fan but I assume you already have 100% fan.

Really the best cure for me is to make parts stick like hell. Then it can hit the part as hard as the head wants - hard enough to shake the house - but no big deal.

There are other fixes - such as occasional supports on overhangs. Please post a photo of the part where the head hits the part. But if the part never comes off the glass then no big deal.

[gr5 2,172]

>Find it strange i have to manually do this for an ABS print, why cant cura/ultimaker do this automatically for me.

I totally agree.

[renarj 0]

So after quite some fiddling i have this ABS sticking issue down and had quite some nice prints with ABS. However today I had my first failed print when i got home where i had layers split on me in the print. Strange thing is that I had two almost identical objects being printed where one was on the left side of the build plate and one on the right side.

The left one seems to have a layer split, find it so strange that only the left object has this problem? In the picture you can see layer split on both the left and middle object which where on left side of build plate, the right object is totally fine and perfect.

Used temp setting of 255 for nozzle and 85 for build plate and build plate adhesion is excellent to the point i have trouble getting the prints off the plate now.

What am i doing wrong? Is this a fault in bed levelling perhaps, i have active leveling still on?

Edited February 7, 2017 by Guest

[gr5 2,172]

The split is caused because the ABS is shrinking but you have crappy layer adhesion. You can't do anything about the ABS shrinking but bad layer adhesion will be a problem for all your parts. Layer adhesion is the second major issue people run into with higher glass temp filaments like ABS and is another reason PLA is so awesome.

The problem is that as a layer is going down it is not fully melting the layer below so it doesn't bond well (never ever a problem with PLA!). The solution is not as easy as getting it to stick but here we go.

First it really helps to heat the air. So as soon as you set your bed to 100C warmup put a box on top of your machine. I just use a random shipping box that fits close enough with lots of space in the back for the bowden. The boxes that are sitting next to photocopiers at work are the perfect size. also put some saran wrap or someting on the front of the printer. These 2 things should bring air temp from 20C to around 35C (hotter than 50C may be bad for your steppers but it's unlikely you can get the air that hot!)

It also helps to lower the fans. For um3 I like around 3% fan. For UM2 I like around 30% fan. If you have zero overhangs and the part is large enough you can go to 0% fan. so for those 3 parts in the photo - if you print all three at the same time you will need a little fan for the holes but nothing else. But if you only print one of those at a time you will need a fan or the parts won't cool down very well and will look bad.

It also helps to raise the nozzle temp but unlike PLA which has a huge printing range (180C to 240C) ABS has a very small printing range. If you go even just 245C and stop printing for a minute and walk away you will cause a nasty nozzle clog. So I usually am careful to never let the nozzle stay above 220C without it constantly printing. 240C is a good compromise ABS temperature. 230C is too low for me - I get layer bonding issues.

Note that layer bonding issues aren't detectable unless you stress the part enough to break it. If it breaks along layer lines (ABS often does, PLA never does) then you have layer bonding issues.

[renarj 0]

So today I have done a longer print again and with a cover both on the top and the front window, here is the result:

I have printed with a layer height of 0.2, speed 40 mm/s, temp 255 and bed at 100 degrees. Yet i still see the lines on the print being unequal for a bit?

Is this just the level of print i should expect? Anyway unfortunately i will have to send the printer in for repair now as the slider block is cracked (known issue) before I can experiment further.

But just want to confirm if this is as good as it gets for ABS on the ultimaker?

[gr5 2,172]

@renarj please update you profile to show that you own a UM3 so I don't have to read your first post everytime I forget.

Um - UM3 can do better than that with ABS. That looks like Z axis issues, or maybe temperature fluctuation. You can go into the tune menu while it's printing and see if it's fluctuating a lot - it would have to be at least 5 degrees to see that kind of difference in layers. More likely your z axis isn't always moving exactly 0.2mm when you ask for 0.2mm. If it moves less then you get a somewhat overextruded layer that sticks out a bit. If it moves more than .2 then underextruded and sticks in.

Usually the fix is to clean the Z axis. This can be a frustrating thing to get perfect though and you might actually have to somehow figure out if it is the Z nut, the Z bearings, the Z rods or the z screw (z screw is least likely the problem). Pushing it up and down repeatedly and feeling if it binds (higher friction somewhere) might help. Some people put a brick or something on the back of the platform and sometimes that helps. Google about Z screw issues on UM2 and you will get basically identical answers for any possible um3 issues. People are often lucky - a quick 2 minute clean with paper napkin and suddenly it's all good. Also white and black filament shows up horizontal banding more than other colors in my opinion.

[gr5 2,172]

Actually zooming in maybe this *is* as good as you can get with white filament on horizontal banding. The remainder quality will look better at 0.1mm layer height.

[renarj 0]

I also suspect the z-axis movement to not be entirely perfect, will check this when the printer is back from the slider block repair.

Have updated my profile. Thanks for all your help its really invaluable helping me forward with ABS prints