How do you folks stop ABS layer delamination? The room’s temperature is ~70°F. I’ve varied the number of perimeters (3-5), % infill (20-40% rectilinear infill), speed (down to 35mm/sec), hotend temperature (230-260°C), layer height (0.25mm - 0.35mm) using a 0.4mm Prusanozzle and a Prusa i3. About the only thing I haven’t tried is putting a box over the whole printer to see if increasing the ambient temperature of the print space might help. Here’s what I’m currently getting, which is a ~6 hr print. I can literally hear the part cracking as I print it. 
Any ideas? I’m using Ultimachine 3mm Natural ABS.
https://www.flickr.com/photos/sbgraber/14411583864/
https://www.flickr.com/photos/sbgraber/14411583864
Higher temps, slightly over-extruding and a heated chamber work for me. Plus, you need to be absolutely sure that the layers are evenly thick.
Encasing the printer, and increasing infill is the only way I can prevent de-lamination. I don’t see a mention of a heated bed, does that mean you’re not using one? What about fans on the hot-end?
I use a PEI heated bed heated to 115°C and I’m using a 3mm Prusanozzle with a 25mm fan pointed at the fins, using an enclosure so the draft isn’t pointed @ the surface of the ABS.
check out the “Print Troubleshooting Pictorial Guide” here
http://reprap.org/wiki/Print_Troubleshooting_Pictorial_Guide
i found your failure under “Part Temperature, Too Cold 01” there are some good corrective actions there as well. the easiest to try is to print a surrounding Skirt full height to keep in the part heat and allow the part to cool slower. good luck
I’ll give the full-height skirt a shot and if that doesn’t work, I’ll try enclosing the entire build area with a cardboard enclosure. If that works, I’ll build a permanent one out of acrylic. Thanks!
Just to be sure, you adjusted the E steps/mm or adjusted the flow rate multiplier to compensate for the smaller effective extrusion rate of ABS versus PLA?
I’m definitely not over or under extruding as that’s one thing I’m actively watching as I print an object.
Yeah…cardboard box (top might not be as necessary) should help. The enclosure will surely help too. For any heat difference in a room, there are convection air currents which means you will get a draft even if you do not have a draft elsewhere in the room.
I would consider your layer heights as “fat”. I have a 0.5mm nozzle and I use 0.2mm layer heights. I do not know if others would agree with me or not, but I do not personally think you have enough squish for your layers.
Your flow ratio will probably change based on your specific roll of filament, but you may need to adjust that as well.
You should try to dry your ABS. Maybe it is too wet ane it is causing delamination.
If it were “wet”, I would surmise I would hear popping coming from the nozzle along with a bit of steam though, and I observe neither…
Not all ABS is born equal, some of it forms much stronger bonds than others. It’s a bit of a crapshoot, but do try a few brands. Keeping ambient temps and extruder temps up is also a really great way of helping.
@Shane_Graber I used to have the same problem. The best thing I found is to not have a draft going across your bed, also the larger the surface area of the part on the bed the more it is going to cause a heat-sink effect on the top of the part, causing it to cool off and shrink. I heard the shrinking effect of ABS when cooled is a desired effect in mold making. the object is injection molded in a cavity and then they run cold water through the mold releasing it without lubrication, it cuts out like 3 manufacturing steps. So basically you need to keep the part you are making as warm as possible because it was designed to deform on cooling.
@Nuker_Bot_NukerBot_3 which leads us to the question of why we use ABS as opposed to something that does not shrink when cooling.
@NathanielStenzel I think the reason is because it is a common formulation recipe and people just got used to it.