Introduction: Failed 3D Prints, and How to Fix Them
3D printers are seriously cool, but as of right now, they are new technology and pretty unreliable. I have a year of 3D printing experience, and I have tried and failed again and again trying to print various models on my printer. However, after failing that many times I have learn a thing or two about settings and tricks to get 3D prints right the first time. If you have any questions, ask away in the comments, and please vote for me if this is helpful!
Step 1: Bed Adhesion
This is probably one of the most common ways any 3D print can fail. 3D printers work by building up objects layer by layer, and if the layers come off of the bed, you usually end up with plastic spaghetti instead of a clean printed part.
Three things contribute to bed adhesion:
- The bed surface (PET tape, glass, or other types)
- The material you are printing in (PLA, ABS, Nylon)
- And the heat of the bed (usually between 60 degrees and 90 degrees Celsius)
The best adhesion I've found for ABS consists of a 80-90° bed, PET tape, with a thin film of Elmer's Glue stick on top.
The best adhesion I've found for PLA is a 0-50° bed, PET tape or uncovered glass, and Elmer's Glue.
Suggestions and methods from comments include:
- Member gravityisweak suggested his method:
Use hair gel from the dollar store on hot glass for rock hard adherence with PLA.
- Member MikeTheSpike says:
I print ABS at 220 degrees Celsius on a 110 degree bed.
Step 2: Over Extrusion
Another common fail is over extrusion. Over extrusion happens when your 3D printer pushes out too much plastic too fast, causing a jam in the end of the nozzle. This jam builds up more and more until the hotend stops extruding altogether, leaving your print unfinished.
The best ways to prevent over extrusion are:
- Make sure you layer height is less than your nozzle diameter
- Increase your cooling fan's power (this will cool the plastic and cause it to slow down)
Step 3: Under Extrusion
On the flip side of over extrusion, under extrusion happens when the plastic coming out of the hotend is too cool. The layers are not hot enough too bond, and the print falls apart easily.
The best way to stop under extrusion is checking you nozzle for clogs, and increasing the hot end temperature. I suggest increasing it in five degree increments until you get a part that has good strength and good nozzle flow.
Step 4: Filament Gets Knotted
One of the most frustrating fails is when your filament is looped under itself and tightens until it is not extruding at all. The only way to fix this is:
When you change filaments, always make sure to hold the loose end firmly and put the spool back in the box, so that the end cannot slip under itself.
Step 5: Incorrectly Leveled Bed
On any 3D print, the bed must be perfectly level, or various problems will happen during the print, such as:
- Your part will not adhere to the build plate
- You part may warp
- The print can have blobs on the z layers
- The print will fall apart easily
Leveling your build plate is relatively simple.
Watch this great video on how to do it, or use my guide below.
Note:This video is not mine and I take no credit for it.
To level a 3D Printer's build plate (AKA print bed) you will need:
- A 3D Printer
- An Allen Key
- A Piece of Paper
Take a piece of letter paper, normal weight, and fold it in half. Place it under your 3D printers' nozzle and home the hotend onto the paper. The paper should be sandwiched between the bed and nozzle. Now, try to slide it out from under the nozzle. If the paper moves freely, the nozzle is too high above the print bed. If there is too much resistance (you have to pull firmly on the paper to free it), the nozzle is too close to the print bed.
Using your findings from step 1, take an Allen Key that fits your printers' bed clip, either:
- Loosen the Allen screw to raise the bed (Do this if the paper moved freely)
- Or tighten the Allen screw to lower the bed (Do this if the paper was to tight)
Repeat steps 1 and 2 for all four corners of the build plate.
Step 6: Print Print Print!
Have a good time 3D printing. It can get frustrating sometimes, but every time you fail, figure out what happened, and prevent that from ever happening again!