Poor Layer Adhesion w/ ABS on TAZ4

General Hardware
1

Here are the specs of what I am printing:
Filament: IC3D Black ABS 3mm
Wall Thickness: 2mm
Height - 75mm
Extruder Temp: 230C
Bedplate Temp: 85C w/ PET tape and ABS/Acetone solution
Room temperature: 65-70F
Layer Height - .22mm
No supports
Slic3r Version: 1.1.7
Slic3r Config: Lulzbot ABS Medium Config
CAD software: FreeCAD
Sending gcode with Printrun

ini and stl attached
gcode is 10MB, not sure how to upload.

I am new to 3d printing and this is the first machine I have owned. I am trying to print a simple cylindrical object with a flat base for use as a cup holder. After several prints and adjustments I am still having significant issues with layer adhesion.

Initially, it was obvious we had an issue with the bed plate level. The cylinder printed extremely lopsided and would error out after about 10mm up the z-axis (one pretty disastrous as you will see). We printed on painters tape because we had a little accident with the PET tape the printer shipped with (oops). We knew we had an issue with either z-axis level or the painters tape was throwing us off.

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Yeah, this isn’t right. Notice how lopsided the base piece is in the lower left

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Another not so hot attempt

We got our PET tape in so we laid that on the bedplate. We also adjusted the z-axis to get a snug fit of paper under the nozzle at all 4 corners. The print looked promising while printing. We needed to super glue a spot mid print but overall it was looking much better than our previous attempts. However, it was all for show, for when we tried to remove it, layers snapped apart in a slinky like fashion.

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Looking better at initial print

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45 degree angle cleared with some errors, super glue applied at the bottom of 45

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Removal Results

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Top section separates like a slinky

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Poor adhesion at the base as well

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45 section is actually pretty strong

After this we switched to IC3D Blue ABS 3mm Filament and changed the layer height to .14mm, same settings otherwise. The result was really nasty.

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Now I am just looking for advice on getting a solid print or maybe a suggestion as to why we are having so many problems.
medium_ABS_no-support_pt35nzl_pt22layer.ini (3.18 KB)
printCupHolderBase.stl (157 KB)

2

Have you tried lower temperatures? I have a strong suspicion that the ABS expands proportional to extrusion temperature and then shrinks when cooling down. This can create cracks in the print if the expansion is too high or the cooling is too fast. When lowering the temperatures these cracks don’t appear. A shroud around the piece keeps the newly printed layer from cooling down too fast. An enclosure for your printer can also contain the heat better.

Try going down in 5 dC steps and check the lowest temperature you can reach. I’ve printed Lulzbot ABS filament at as low as 206 dC with 0.5 mm nozzle and 0.2 mm layer height. Make sure you’re bed leveling is near perfect before experimenting.

3

Thank you for the reply!

No I had not even thought to consider that the temperature was too high and it was an expansion/contraction problem. If anything we only considered increasing the temperature in an attempt to perhaps melt the next layer more into the last layer. So thank you for the suggestion.

We are going to spend some more time checking our z-axis level. Are there any other high precision methods to check z-axis level out there? We were considering maybe even mounting some sort of dial gauge to the extruder and getting high precision readings across the bed plate. Then an enclosure might be a good idea to look into as well.

Should a beginner start with a simpler filament material like PLA? We would like to use some of these prints practically in automotive interiors, so some ruggedness and temperature resistance would be ideal.

4

So far the “paper method” for z bed leveling has served me well. It works fine getting the corners level relative to each other. Once that is set it stays. In fact i reckon the only reason i readjust it is when out of frustration i mess with it. Take your time and get the paper to slide with just the right amount of friction with the z axis homed. I do it 10 cm in from the corners for each corner. I change the extruder quite often and so have to readjust the main z axis stop button screw. You do not have to readjust the corners unless you’ve really jarred something into the bed. I like to approximate the z-axis stop button screw position and then just adjust the height based on the thickness of the extrusion. The stock calibration file is good for this! OK, so bed is level and now that’s one less thing to worry about.

I made the mistake of trying higher temperatures for ABS thinking it’s a layer adhesion problem but that never solved the problem for me. That’s how came to the expansion/contraction theory. You can also experiment with the “extrusion multiplier” or just use something like 2.85 mm diameter for filament quoted as 3 mm. You’ll probably end up over extruding getting blobs forming on corners but just ease back on those numbers when you’ve overshot. These blobs are usually easy to remove after printing anyway.

PLA is great for overhangs but fans and ventilation is crucial to get good results. ABS will stand better to higher temperatures and i like to use acetone get a nice look or better layer adhesion after printing. There are loads of other filaments out there but these two will give you a good grounding. I’m experimenting with xt-copolyester at the moment.

5

It looks like you are using the stock Medium Slicer settings.
Did you actually measure the diameter of the filament with digital calipers? The setting is still at 2.89… My measurements for most filament is 2.88. Although for Lulzbot black I’m using 2.92. Also for the Black I use an extrusion multiplier of 0.92 as for me the black seems to over extrude.
If the Filament diameter isn’t spot on your prints will most likely fail.

For Bed adhesion I use the purple, washable, elmers glue stick. It works GREAT. I think the acetone solution is too dangerous for where I have my printer setup and I like being able to cleanup with a damp rag.

Also, never try and remove a part with the bed still hot or even warm. It will either break apart or you will damage the bed or both.

Also, you can’t really just change the layer height by itself and get good results. There are a lot of other settings that need to be tweaked as well. Best bet is to load the “Fine” setting from Lulzbot and tweak them with new filament diamenter, extrusion mult., etc.

And, if the printer is near any kind of draft, open window, fan, air duct your ABS prints will crack. I work exclusively with ABS and while I still get an occasional crack, the printer works exceptionally well. If I built an enclosure for it that would most likely eliminate the cracking problem. I just haven’t gotten around to doing that yet.

Oh, and I print almost everything with a few tweaks to the stock Medium 0.22mm settings.

Best of luck.
Wizard

6

ABS and PC (to a greater extent) will have layer seperating issues caused by low ambient temperatures (in my experience) To get away from layer seperation, the TAZ needs to be in an enclosed space and kept warm inside. Prevent AC vents from blowing on your printer. What temperatures do you need? not sure yet.

7

I greatly appreciate all the replies. We decided we will start with the enclosure first. We will report back with the results.