3D Printing Tips & Tricks
Welcome to our 3D printing tips & tricks page. This is a collection of short write-ups we’ve made from mostly our experience through the trials and tribulations of 3D printing including 3D printer software usage. This is tailored to the beginner and intermediate level 3D printers. We hope this becomes THE place to check out when having a printing issue. The tag / filter system allows you to quickly get all the quick tips within a category.
Little particles on the Inside Corners
I’m not sure what to call this phenomena, but basically little particles form on the inside corner(s) of your print and create a little worm-like structure along with some stringing. The example pictured on the right is printed with the same settings as you would choose for a vase: zero infill, zero top layers. However, there is an additional structure in the middle of the part.
Solution: In Slic3r configuration under Print Settings > Infill , uncheck “Only retract when crossing perimeters.” What happens is Slic3r thinks that the nozzle is still within a filled layer even though infill is set to zero, and doesn’t recognize that you want two clean and distinct boundaries.
Detailed Prints and Gradual Overhangs Without Using a Fan
For many reasons, we love printing in ABS. The tricky part comes when you want to print certain small fine details or parts that have gradual overhangs. Gradual overhangs tend to curl up with each layer because there’s no “anchor” below it so tries to shrink inward. With PLA, you would typically use a fan to blow air at the part. You can do this with ABS too, but this can cause cracking with taller prints due to poor layer bonding.
A little trick we use is to design and place a little tower as tall as your print and position it close to your object. When you print these parts together, the tower does two things: 1) it allows the layers of your primary object more time to cool, which reduces the tendency to curl, and 2) allow the nozzle to stay clean and not drool, compared to other non-fan cooling methods such as “slow” and “orbit.”
photo 2 (1)
REMOVING A PART FROM YOUR PRINT BED
Problem: “I can’t remove my part from the build platform.”
Sometimes, a part can be stuck to the print surface really well and you’re unable to get good leverage to pop it off. When printing a pyramid shape, it’s even difficult to get at it with conventional tools. Here are a few tips:
Bring the temperature of the heat bed up (or down) to about 60C for ABS.
Wrap the jaws of a pair pliers with a rag and try to get some leverage somewhere on your part.
Wrap the end of a chisel with some tape and carefully work at a corner of your part. The tape just protects your Kapton or other printing surface from getting scratched.
COMBAT WARPING WITH PADS
Sometimes, when you’re printing a large flat object, such as a simple box container, or a very long thin feature, like a stick, you may see warping at the corners or extremities. One trick is to add little pads to your part where the warping would occur. These can be any size & shape you’d like, but generally, diameter 10mm cylinders that are 1-2 layers thick work well. After the part is printed, just trim them off. Here are two techniques to add pads to your part:
Add pads to your 3D data. Use this method if you plan on printing several parts over time.
Add pads to your part in Repetier (or your GUI of choice). This is a great trick (thanks Charles H.!) for quickly adding pads to parts that you might not be able to easily modify (i.e. STL files, SCAD files, etc.). Just create a pad shape in your CAD package of choice, save as an STL, and add it to your build tray. Quickly add as many as you want and easily move them around!
REPAIRING AN STL FILE USING NETFABB
Problem: “I’m getting unexpected (bad) results from slicing my STL file.”
When slicing an STL file, sometimes the result you get are not what you expected (i.e. features missing, different geometry, etc.). This is often due to the actual STL data not being “perfect” in the eyes of the slicing engine. Most times, it’s difficult to see where the actual “bad” portion is located. Other times, it’s just downright too time-consuming to troubleshoot. The best method, as a first line of defense, is to use the powerful and free STL repair tool by netfabb. The free version is called netfabb Studio Basic and you can get it here. Here are a few quick steps to follow once you load your part into netfabb:
Go to “Extras -> Repair Part”
Click “Automatic Repair” (bottom right) and Execute the “Default Repair”
Click “Apply Repair” (bottom right)
Right click on your part in the file tree (right side) and export it as an STL to your preferred location.
ABS glue is a great addition to any 3D printer operator’s tool box. This slurry of acetone and ABS has many practical uses such as:
Bonding small parts together to create larger or more intricate ones (it’s just a bit easier to apply than straight acetone)
Improving the surface finish of your part (simply paint it on or dip your part into it)
Mending cracks in your parts (if you don’t feel like reprinting/redesigning them)
How to make ABS glue:
Use a small glass jar with an air tight lid. You can find these at most hobby shops. Empty nail polish bottles work too, but they’re kind of small.
Fill about half way with straight acetone (or however much you’d like if you’re using a larger jar).
Add ABS. ABS takes time to completely dissolve in acetone, so the smaller bits you use the quicker the results. We like to simply print a 1-layer thick square sheet (or just start any print and stop it after the first layer), and then cut it into pieces. Snipping small pieces off the end of your filament works too, but it’ll just take more time to dissolve.
Wait and stir. Repeat until all the ABS is dissolved.
There’s no perfect ratio of ABS to acetone. Just use less ABS to make a thinner solution (great for surface finishing) or more ABS for a thicker solution (great for bonding or mending parts).
PRINTING LARGE OR UNIQUELY SHAPED PARTS
If you need to make parts larger than the printing area of your printer or parts that have intricate projections, here are a few choices in order of popularity:
Fuse smaller sections together using acetone.
Design smaller parts to be attached together (without hardware).
Design smaller parts to be screwed together (with hardware).
EXTRUSION TEMPERATURE FOR ABS
The optimal temperature for extruding ABS usually ranges between 215-240C. These are some factors that can influence the optimal temperature:
Hot-End design : How accurate is the temperature reading vs. the actual temperture of the hot-end? Some factors to consider:
distance between tip & heater resistor, thermistor & heater resistor, and thermistor to tip
Moisture in the Plastic
Temperature of the printing environment
Elevation (from sea level) of the printing environment
CRACKING ON TALLER PRINTS
Problem: “There are layer cracks on the sides of my taller prints.”
This cracking phenomenon can occur with taller prints. The reason is because at higher layers (say from ~30mm on a typical Reprap), the part cools quicker and has less “help” from the heated bed. Therefore, subsequent layers cool down faster and faster which causes poor layer adhesion. Try increasing the extruder temperature by about 10C. Also, try increasing the bed temperature between 5-10C.
SLIC3R SETTING SAVE PROBLEM
Problem: “My Slic3r setting changes are not being saved even after I click ‘save.’”
This is commonly a problem for Repetier installs on Windows 7 PC’s. In Repetier, make sure the “Work Directory” (Config -> Repetier General Settings) is not in your “Program Files” folder (usually C:\Program Files). In short, Repetier creates and/or writes into a log file every time slice settings are changed and there is some issue with permissions.
X OR Y DIMENSIONS UNDER-SPEC
Problem: “The dimension of my part in X (or Y) is suddenly under-spec.” -or- “The sides of my round object are flat.”
If your printer was known to be printing with dimensions within tolerance (meaning the settings in the firmware are good) and all of sudden parts are measuring smaller, check the tension of your drive belt. Loose belts will require the motor pulley to need to take up this little bit of slack before the extruder/print bed gets moved. This results in parts being undersized. If for some reason you have difficulties tightening your belt, try printing and attaching one of these nifty little S-clips (Thing:10082).
Problem: “The base of my part is warping.” Try these tips:
Is your heat bed hot enough? For ABS, this is generally set between 100-110C.
Is there a breeze or draft blowing across your printing area? Turn off that ceiling fan, or build some make-shift walls to surround your printer.
Do you have a good connection between your bed thermistor to the actual bed? (ensure that the thermal paste is still effective, i.e not dried up)
If printing with ABS, is your Kapton tape surface clean? Try occasionally wiping it down with acetone and/or rubbing alcohol.
Are you printing very wide or thin features? Try adding little pads to the corners of your 3D data to use as anchors (Check out the tip “COMBAT WARPING WITH PADS”).
Do you have enough 1st layer squish? Insufficient squishing of the first layer can cause poor adhesion, leading to a warped base.
Are you printing your first layer too fast? Trying slowing down your first layer speed to around 30mm/s.