Through trial and error we have slowly honed in our profile settings for different 3D printing materials. This is our second profile tutorial and today we will be taking a look at the settings and profiles that have worked for us while printing in ABS.
Further than just explaining preferred temperature settings, we will be taking an indepth look at advanced support and infill settings, as well as many other factors that go into making a clean and successful print.
ABS is quite unique to PLA for a few reasons. The first is the difficulty to print. Small items are quite easy, and the printer can handle ABS without any issues. The problem arises when printing large parts. Since ABS has a high shrinkage rate which causes warping, we will only print larger ABS jobs with our proprietary enclosure or on our fully enclosed 3D printer.
ABS also allows for the ability to post process using acetone vapor finishing, something we always suggest doing to enhance the strength and look of ABS parts.
***Disclaimer: The following ABS settings are for Cura and work well on Lulzbot TAZ printers with an E3D hotend. We have used these settings on our TAZ3 and TAZ5 printers with HATCHBOX and E-Sun 3.0mm ABS with success. When using Simplify 3D we use very similar profiles. Environmental conditions and filament origin can heavily impact these settings as well***
The layer height of your print is very dependent on the nozzle size of your printer as well as the quality of the print you would like. We run our ABS settings for quality extremely similar to PLA (in case you had already read our PLA Settings guide). A printer with a .6mm nozzle can go up to .4mm layer heights, and a part with .1mm layer heights will take twice as long as one at .2mm, so these factors are important to consider.
Our standard quality print settings are at a .25mm layer height. We then hone in the retraction settings for ABS. Upon clicking the “…” next to “Enable retraction” we have our profile as such:
Minimum Travel: 1.5mm
Enable Combing: All
Minimal Extrusion Before Retracting: 0.005mm
Z Hop When Retracting: .1mm
Combing refers to the printer head following the path of the print rather than attempting to clear gaps. This will help prevent “hairy” sides of a print. The Z Hop when retracting is set to a small .1mm so that skinny prints are less likely to be knocked off.
When clicking into the Advanced Settings tab we then take a look at the Retraction and Quality sections of Cura. We set our retraction speed to 10mm/s and our distance to 1.5mm. Within the Quality area of the Advanced section we do not increase the initial layer thickness but we do increase the initial line width to 110%. We have found this to help stick to the bed without impairing the print quality.
In order for a clean ABS print, we always make sure to include a minimum of 4 bottom/top layers (meaning you would multiply layer height by at least 4). This is even more important when dealing with ABS than with PLA.
This can increase depending on how flat the object is, how high fill density is set to, and how thick your layer height is. A long rectangle piece with a .1mm layer height will require over 10% infill and at least 8 bottom/top layers in order to not have a pitted look. The print below had that exact issue: too small of infill and too few bottom/top layers – leaving the print unacceptable for a final version.
This part was printed with only 15% infill, .25 layer heights, and 1mm Bottom/Top thickness. Something this thin and flat requires at least 5 top bottoms or at least 25% infill.
Prefered fill density percentage is unique to your particular print, similar to the quality settings. That being said, you can click on the “…” on Cura in order to have some advanced settings. The infill overlap settings are where we played around a bit in order to perfect the surface quality of the print.
Infill overlap refers to the percentage the infill will overlap onto the shells. When having a small numbers of shells, and infill overlap % is set above 12%, we notice a “veiny” look to the surface of prints – especially large parts in a translucent PLA color. For ABS, this is definitely not as noticeable. Since we have had no issues, we have kept the infil overlap the same that we have for PLA – 8%.
Speed and Temperature
As we warned above, these settings work well with our Lulzbot TAZ printers with E3D hotends. These temperatures (and speeds) may vary depending on the printer, hotends, and filament you use.
Our nozzle runs at a comfortable 230°-240°C for ABS. We normally run our bed at 110°C in order to prevent warping as best we can. As mentioned, larger parts do need to be in an enclosed environment. Preventing delamination and warping is near impossible otherwise due to ambient temperature grades.
We run our printers a bit slower in order to ensure the best surface quality possible. We normally set our average speed to 60mm/s, with slower settings for the outer and top/bottom layers. In the advanced we have our speed set to:
Travel Speed: 150mm/s
Bottom Layer Speed: 30mm/s
Infill Speed: 60mm/s
Top/Bottom Speed: 40mm/s
Outer Shell Speed: 40mm/s
Inner Shell Speed: 60mm/s
We would like to emphasize the high probability of warping when printing in ABS on a non enclosed printer. Even with our fully enclosed 3DGenie which keeps the ambient air at 55°C, some very large prints will still warp.
Pictured to the left are two examples of this warping effect. Not only can this cause a “skateboard” effect to your flat parts, taller prints can actually delaminate. Since open printers are so much colder near the top of the print than the bottom with the heated bed, top layers will try to rip themselves from the hotter lower ones due to the shrinkage rate of ABS.
We have found that support settings are one of the hardest things to dial in. Not only does each material require a different fill amount percentage and angle, they each also require unique distances from the print for easy removal.
Anyone who has printed long enough has likely come to dislike working with support settings. ABS especially (when compared to PLA), really requires these settings to be perfected. We have been able to make support removal a minor chore and still have a clean under surface quality to our prints. After clicking the “…” next to “Support type” we have our specs as follows:
Structure Type: Lines
Overhang Angle for Support: 45°
Fill Amount: 23%
Distance X/Y: 0.7mm
Distance Z: 0.13mm
ABOVE: The same piece (mirrored) with different support settings. The left has our newest profile settings
Within the same section as the support settings you will also find the platform adhesion type. Since ABS is very prone to shrinking and warping, it is very important to make sure you use these features. I will usually do a brim, or a .01 distance skirt, with at least 15 lines for larger ABS prints.
If you choose to do a close skirt instead of a brim, upon choosing “None” for the Platform adhesion type, click on the “…” for more options. We then change the line count to 10-20, the start distance to .01mm, and the minimal length to 250mm. This allows for a brim to only be on the outside of the print. You may have noticed that setting a brim on your print will also add it to center holes, which do not require such structure support.
Removing brim and skirt is a lot easier on ABS than on PLA, so it isn’t much of a hassle to post process.
And then finally the last section in the advanced tab is the ability to activate and tweak the active cooling fan. When printing in ABS, especially on larger prints, this cooling fan will not be needed. We still like to have our minimal layer time set to 20 seconds, but the cooling fan is unchecked. The only times where we have decided to turn that fan on for ABS is when the prints are very tiny.
One of the best parts of printing in ABS is the ability to acetone vapor finish your parts. PLA and other materials are not soluble in acetone, making them unable to be post processed this way. This is something we have played around with a lot here at SD3D. Not only can it make a print stronger and more water tight, it also gives a great finishing shine to parts that resemble an injection mold quality. Prints are smoother to the touch and overall easier to work with after acetone vapor finishing.
You do have to keep in mind that overexposure can lead to a destroyed print, so use caution when proceeding with these steps.
**CAUTION** Acetone is EXTREMELY flammable, and this process should only be done in a well ventilated area with no open flames.
Step 1: Prepare your slow cooker in such a way that you are using a metal grate (often comes with the slow cooker). This metal grate needs to be entirely taped off on the bottom with packaging tape. This will help prevent the acetone from bubbling up and accidentally directly splashing your part during the heating stage.
Before turning anything on or inserting the metal grate, be sure to add a few tablespoons of acetone. Again, it’s better to insert small quantities of acetone across multiple exposures rather than attempting one big exposure. Above all, you do not want your 3D print to be directly touching the acetone or heated surfaces.
Step 2: Place your part on the newly taped off metal grate and put into your slow cooker. You will then close your slow cooker and put it at the LOWEST settings. This is a VERY fast process, so do not try this without reading all of the steps and researching futher.
Leave your part on the metal grate in the warm cooker for no more than 45 seconds! We have a method down where we leave on for 30 seconds, off for 15, and then on for 10 final seconds. This process will vary with each slow cooker you use.
We actually have a big broiler with a similar setup that we put onto a hot plate for larger ABS prints. This process requires roughly 10 minutes though, due to the large volume of the broiler.
We recommend that you always error on the side of less time. You can always do another round of acetone vapor if you determine that the print requires it.
Step 3: After your quick acetone vapor bath is complete, remove the grate that is holding your part and put the two off to the side (onto a countertop that you do not care about). After allowing for 30 minutes or more for drying, you can remove the part to be vacuum purged.
This step is not needed but definitely helps with the strength of the part as well as the time required to dry. Doing the process above without a vacuum purge will require 24 – 48 hours before the part is to full strength.
While we have had success with these settings, there are times when particular models and prints require minor changes to this formula. Specific geometries may require your support settings to be slightly closer in the Z or X/Y direction.
There are many times we will also use Simplify 3D which requires its own set of custom ABS settings. Normally we turn to slicing with Simplify 3D when Cura does not put support where it is required. Simplify 3D allows for the ability to add manual support when Cura cannot. Cura is also limited to a square infill pattern, so if you want to use the honeycomb, triangle, or another unique style of infill, you will need to use a different slicing program.
Make sure to save your ABS settings in a location that is easy to maintain. Create a protocol for organizing your ABS settings for Cura and make sure to keep them in a seperate folder from your ABS settings for Simplify3d. These 3D print profiles are not backwards compatible and will only work when loaded into the program that they were generated from. If you want to learn more about how your ABS settings and 3D print material profiles affect the strength of your parts – check out Optimatter, a free 3D printing material optimization tool.
And finally a quick screenshot of our Basic and Advanced settings for easier reference: