More ABS, More Problems!
This is a small elbow joint, where the bottom should look a lot more like the top. What may be the cause of the extreme gradient of the curvature and pilling towards the bottom, but be perfect on the top? I began the print with the heat bed at 110C, and after the first couple of layers dropped it to 70C, thinking that prolonged exposure to the heated bed that was too hot might be causing it, but I get this on many ABS prints.
Any ideas on how to remedy this?
Could be inadequate cooling. ABS overhangs do need a LITTLE airflow for good detail. Usually a little wash off the hot end fan is adequate.
I am taking ABS off of my 3D hubs profile, too many variables to be sure that I can fill an order with the least amount of complications.
Try less infill, and faster outer shell, and two shells max, try lower temperature in steps of 5 each 3minutes, might want to experiment with different speed of cooling fan too
@Nathan_Walkner That makes sense, but I get a lot of conflicting advice with ABS, and I’m guessing it’s because there are too many variables unique to each machine and each user’s ambient environment that will affect print quality to the point where, even in the most optimal of circumstances, there is still a wild card factor - season, curvature of the earth, moon phases maybe - that makes ABS a less reliable printing medium. I’ve had some great prints with it, but I can’t rely on consistent quality enough to make it something I’d offer as an option to clients who are paying me for jobs with deadlines that I can’t make because of a droopy layer or a sticky support five hours into a seven hour print.
@Michael_Anton1 ABS is insanely reliable and consistent when you print it in the right environment. Specifically, a hot build chamber and lots of hot airflow. (~80C is optimal but most printers can’t achieve that.) It’s arguably THE BEST material for FDM in those conditions. Look at all the Stratasys industrial FDM machines. They’re all using ABS in heated build chambers. The problem is, the cooler the printing environment is, the more difficult it becomes to print, and the more brittle the final print is.
This is a function of the glass point of the material. Printing in a chamber around 20-30C cooler than the glass point, with lots of airflow, will give optimal results for every kind of filament. But the colder the chamber is below that optimal temp, the less airflow you want. This applies to PLA too – put a PLA printer in a very cold garage in the winter with a big nozzle blower and it will be warpy and delaminate just like ABS. It just so happens that PLA’s optimal printing environment temp is right around room temp. That’s why it’s easy to print.
You get inconsistent advice from the community because ABS is very difficult to print in a cool environment (because of physics) and everybody has their own little hacks and kludges to try to overcome that. Heated beds, brims, printing multiples of small parts, etc are all kludges to make up for printing in the wrong environment for the underlying material properties. You CAN get very good results with those tricks, but different combinations of tricks are required for different part geometries and sizes. So yes, it’s complicated to get good ABS results without a hot build chamber, because you’re trying to make up for not having the right printing conditions in the first place.
@Ryan_Carlyle You bring up very good points, ABS is a great medium in the optimal conditions, where the optimal conditions are able to be met immediately. For my setup, those conditions are not so easily met and maintained, and is more problematic when there is a demand for a quick turnaround time.
One thing I haven’t considered in this discussion, and should have from the start, is the quality of the ABS filament I’m using. I know that quality can vary between different manufacturers and even between different lots produced by different manufacturers. What I don’t know is, how long does it take for a good spool to depreciate. With the cracking, and the shriveled first few layers on the models for this order, even in the best of conditions, a poor quality filament can be just as much of an issue.
