Terrible ABS Layer Bonding

I have close to zero problems regarding layer adhesion and strength with PLA and ninjaflex, plus the ABS-compatible MakerGeeks PLA filaments. However, I have a roll of Form Futura ClearScent ABS. This stuff lives up to its low scent name, but for some reason all my prints in it are HORRIBLY weak, and usually break apart from their own warping force.
I printed this at 230°C, which should be fine for ABS, and is fine per FF's specs. 0.2mm layer height, 0.4mm nozzle size, 15% infill, 0.8mm walls, 0.6mm top/bottom thickness. Using Cura 15.04
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Edited 1 time(s). Last edit at 01/27/2016 09:05PM by Montiey.

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Master Tinkerer

Try printing hotter. I run most of my ABS at 240

The default answer for ABS is to use an enclosure to increase the ambient temperature, but as well as printing hotter, you can also try printing slower and wider. I don't have an enclosure (yet), and print ABS at 260 and 30 mm/s which seems to work for all but the biggest prints. I don't think cura has an explicit way of setting the extrusion width, but they would have to base it off the nozzle size, so try setting 0.6mm for nozzle size and see if that helps. Having said all that, your benchy looks pretty good. You might find that by the time you get the layer bonding sorted it introduces some other problems.

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JamesK
The default answer for ABS is to use an enclosure to increase the ambient temperature, but as well as printing hotter, you can also try printing slower and wider. I don't have an enclosure (yet), and print ABS at 260 and 30 mm/s which seems to work for all but the biggest prints. I don't think cura has an explicit way of setting the extrusion width, but they would have to base it off the nozzle size, so try setting 0.6mm for nozzle size and see if that helps. Having said all that, your benchy looks pretty good. You might find that by the time you get the layer bonding sorted it introduces some other problems.

No, setting the nozzle size to .6 will not have the desired result. Take your extrusion width and multiply by shell layers, then in cura set shell thickness to that number. For example .3 nozzle, 120% extrusion width, 3 shells would be .36x3 = 1.08 shell thickness. The box will turn yellow, and the software will complain, but that will achieve what you want in terms of fattening up perimeter traces.

I'll be away tomorrow, but I will definitely try printing hotter. This ABS seems to be extraordinarily fluid, even just above 230.

...Should I try 290 and see what happens? I can't imaging that pure carbon bonds well, but..

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Master Tinkerer

Interesting. But you need to fatten up all traces, not just perimeters - how do you go about that in cura?

A benchy should be printable without a heated chamber, in worst case a cardboard box over the printer will suffice, but making sure no draft occurs is usually enough for a part of that size,
The more prominent problem is the temperature. Practically every ABS i tried over the years worked best inbetween 240-260°C. 220°C might print but it is very likely that you will have layer bonding problems.

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JamesK
Interesting. But you need to fatten up all traces, not just perimeters - how do you go about that in cura?

Hit the close button and use a different slicer? I used cura a lot when I started, but it's level of user control is not high. This seems to be on purpose in order to make it easier for people to use, and I understand that. But for me the answer was to switch slicers. They all have their faults.

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But for me the answer was to switch slicers. They all have their faults.

I've only really tried Slic3r and Cura, I must try a few more at some point and make sure I'm not missing out on something better.

For the Cura extrusion width question, from a quick google search it sounds like Cura automatically chooses widths in a range up to about 150% of the specified nozzle size. I'd hope they don't use widths less than the nozzle size other than for gapfill, so as far as I can see, using the nozzle size as a way of bumping up extrusion width ought to be a reasonable thing to try.

I like the ease of Cura but hate that you dont have the control of Slic3r. And I hate that Slic3r "feels" old and cumbersome and also hate that it doesnt show estimate print time like Cura.

I print 234°C white ABS, no enclosure, no problems. Do you have any other ABS brand filament to try? Perhaps your filament is mysterious scrap?

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Prusa i3, Ramps 1.4. Catnozzle 0.4mm
SketchUp - Enveloping Globoid Worm Gear - Part One - 3D Printed: [youtu.be]
DesignSpark Mechanical & more precise screw thread: [youtu.be]
Nicer Screw Thread In SketchUp ( Bolts,Nuts): [youtu.be]
How To Model A Heart Shape In SketchUp: [youtu.be]
How To Draw 3D Printable Snap Fit Ball Joint In SketchUp: [youtu.be]

I have no reference for how ABS should behave but I suspect that in making it not smell terrible FF may have screwed up the formula a bit. I printed another Benchy at 0.3mm layer height and at 260, and that one worked fine. Nice and strong, although I still got warping on the bottom. I am currently printing @ 264°C and 85°C, but the bed must nearly be on a 100% duty cycle to maintain temp, and takes about 20 mins to even off with my puny PCB heater under a 4.8mm aluminum slab. I am concerned that this will have bad affects on the RAMPS board, more specifically the bed mosfet. It has a heatsink, but is still too hot to touch. The only reason I never though about putting a fan on is that there is WAY too much cabling for anything to work out. Should I stop printing if things get that hot? The stepper drivers are also too warm to make continuous contact with, but the motors are fine.

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Master Tinkerer

264°C is something like for nylon. I use 108°C on my plate and my bed mosfet is very hot. Time to add a fan. 100+ hours of use and no problems , but surely it's more secure to add some ventilation. The stepper driver calibration can perhaps help to lower temps on them.

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Prusa i3, Ramps 1.4. Catnozzle 0.4mm
SketchUp - Enveloping Globoid Worm Gear - Part One - 3D Printed: [youtu.be]
DesignSpark Mechanical & more precise screw thread: [youtu.be]
Nicer Screw Thread In SketchUp ( Bolts,Nuts): [youtu.be]
How To Model A Heart Shape In SketchUp: [youtu.be]
How To Draw 3D Printable Snap Fit Ball Joint In SketchUp: [youtu.be]

Not sure what i'm doing wrong here.. The prints are now much stronger, but still much weaker than my PLA prints @ 212°C. Should I try without the layer fan? Not sure how having a fan would do anything different than replicate the properties of higher areas further from the build plate (layers that are at room temp). If I need all the layers to be hot for ABS, maybe I should try some normal ABS and rule out Form Futura as the problem, (any good sources?)

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Master Tinkerer

Typically you don't want a fan anywhere near abs. I've played with very very minimal part fan settings along with unusually high extruder temps to try and get around the de-lamination problems on taller prints, but I'm not convinced it's a good idea. If your cold end fan spills onto the print that's enough to play havoc with abs.

Edited 1 time(s). Last edit at 01/30/2016 10:46AM by JamesK.