Introduction: Failed 3D Prints, and How to Fix Them

Picture of 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

Picture of 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

Picture of 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

Picture of 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

Picture of 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

Picture of 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.

My Method

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!

Picture of 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!


TomasD32 (author)2016-09-19

I managed to reduce warping and maximise adhesion (PLA) by decreasing extrusion temperature to 195C and increasing bed temperature to 80C for the first 5 layers, then decrease bed temp by 5C every 5 layers. I also used Maple Syrup on the printing bed for it is extremely sticky and super easy to clean. I have 15 consecutive successful prints by following this process.

td10 (author)2016-04-07

i use lemon juice or sugary water when printing pla on to a heated glass bed. Preheat bed, apply lemon juice, it steams away the liquid fairly quickly leaving surface sticky. Other trick is to turn on cooling fan after 3 or 4 layers have already printed

BradBuilds (author)td102016-04-08

Cool! I've never tried lemon juice. Do the prints smell nice too ?

td10 (author)BradBuilds2016-04-08

There is a lemon smell when the liquid boils away then just normal plastic heating smell. I found that the sticky surface can last for 3-5 prints. It is almost too good because do have to wait for bed to cool so the print separates from bed. Then clean with hot water/detergent, dry. Test bed alignment. Then rub with acetone/paper towel to clean grease off the glass surface. Reapply juice then good to go. I got bottle from supermarket so it was reconstituted.lemon juice used for cooking.

TheCoffeeDude (author)2015-12-22

I was pulling my hair out over layers separating on my m3d micro...this helped me fix it. Great ible.

Do you like your M3D Micro and would you buy it again?

I like it a lot and would buy it again, however, it has made me want a larger one for bigger prints too. Its a gateway drug for 3d printing. :)

BradBuilds (author)TheCoffeeDude2015-12-23

I'm so glad I could help! Good luck with you printer,

fdea (author)2016-04-08

Better ABS bed adhesion. Use a light mixture of ABS dissolved into accetone on the bed. I apply it with a small bottle of eye drops. Does not need to be a perfect bed painting, just make a thin paint covering as much place as you can.

BradBuilds (author)fdea2016-04-08

Yes, that does work very well for ABS. The only reason I don't use it is that I switch between ABS and PLA often.

iceng (author)2015-12-12

Great failures can lead to great success !

BradBuilds (author)iceng2015-12-12

I agree!

VectorRobo made it! (author)2015-12-04

Thanks so much! Your story sounds just like mine. I have a Pruda i3 and a Cubify Gen 2 and this is accurate. The picture I attached is one of my earliest prints from a year ago that was pretty awful.

BradBuilds (author)VectorRobo2015-12-04

Thanks VectorRobo!

J SquaredA (author)2015-12-03

BradB5 (or anyone else who knows how to solve this problem),

I print stuff on my school's 3 3d printers. The only problem is that 2 of them stop printing after about 5-10 minutes of printing, sometimes longer. They're Makerbots (below picture is the model I think). It says "Extruder Error" when it stops, but I'm not sure if it is Over Extrusion because there is not silky strands coming from different parts of the print and we don't have to clean out the extruder. We just push the knob twice and it heats up (to 215 C) and starts printing again until it stops again.

HELP!!! My dad won't let me and my brother get our own 3D printer because he says we can just use the ones at our school, but we can only use 1. Does anyone know what is happening???


Dlbray (author)J SquaredA2015-12-04

That model of Makerbot is notoriously bad. It looks like the newest generation that has a "smart" extruder head. One thing that helped ours was turning off "Jam Detection." Another was having the filament go straight up and down into the head without running through any tubing.

J SquaredA (author)Dlbray2015-12-04

Is Jam detection under settings?

Also, would we need an external spool holder to make the filament go straight up and down? There is a shelf above the printers.

BradBuilds (author)J SquaredA2015-12-03

Hi J SquaredA, I personally don't use a makerbot, but with any Cartesian robot (normal 3D printers with an extruder), can have some of the following problems that can cause prints to stop suddenly:

*I would guess that your printer's extruer motor driver (A small board in the electronics box on your printer) is overheating, and needs to cool down. When it does cool, all you have to do is heat it back up and resume printing.

To fix this, I would make sure that the printer is in a well ventilated area, and no sandwiched between anything (desks, wall, bookcases, etc.)

Good luck!

erniehatt (author)2015-12-03

The solution to sticking to the bed is.

On plain glass, I mix PVA wood adhesive with water about 70-30 find this works very well.

After a few prints, simply wipe over the glass with a damp sponge then reapply..

BradBuilds (author)erniehatt2015-12-03

PVA glue, huh? Never heard that before. Cool.

erniehatt (author)BradBuilds2015-12-03

Your welcome,Forgot to mention I heat the bed to 60 degrees.

Spudwiser (author)2015-12-03

What works best for me with ABS, is a slurry of Acetone and
left over ABS. I mix them together in a small bottle (airplane booze bottle). Then
use a Q-tip to smear a thin layer on the glass before printing. This hold much
better than the glue stick.

BradBuilds (author)Spudwiser2015-12-03

Yeah, I used to use slurry, but glue sticks are cleaner and less of a hassle.

PierreGi (author)2015-12-03

Thanks a lot from Belgium :-)
Can you describe or post a picture of that hair gel you mentioned ? We don't have Dollar Stores over here (I know them since I've been living in the US though).

BradBuilds (author)PierreGi2015-12-03

Your most welcome! I will try to get a picture up.

gravityisweak (author)2015-11-28

Ive never tried it with ABS, but for bed adhesion to a glass bed with PLA, use hair gel from the dollar store, you will never need anything else. Your prints will be sold as a rock while the bed is hot, and come off by themselves once the bed is cool. The gel also cleans right up with a wet paper towel.

BradBuilds (author)gravityisweak2015-11-28

I've heard of gel and hair spray for PLA, but since I switch ABS and PLA so much, I use glue on PET tape. Thanks for the comment, I will be updating this instructable today and adding all the suggestions from commentors.

MikeTheSpike (author)2015-11-27

I print ABS at 220 degrees C on glass that's at 110 degrees C, so this may not work for other materials.

Firstly, bed leveling is pretty critical. The first layer needs to be even over the whole first layer surface otherwise you'll get some sections that are either too thin or don't stick to the bed properly. I have resorted to using auto bed-leveling with a capacitive sensor and this works beautifully every time. No more tweaking the bed screws like I used to when I first started. I do a G28 followed by 2 x G29 commands to get the average of two bed leveling runs over four points on the plate. Sometimes the first G29 gets slightly too close to the bed, but usually the second time round it averages out and is spot on. Watch the logs to see the heights reported and if they vary too much between them you will get an idea of which screws to tweak to get them all the same.

Secondly, I use ABS juice (100ml acetone and 2m of 1.75mm filament) and pour it on cold glass. Use some tissue paper to smear it on. I tried the glue stick stuff, but that didn't work for me. Parts popped off too easily and generally left the glass all messy.

Thirdly, put up a wind screen around the printer. Even a slight draft can cause the print plate to cool and cause warping.

And Finally, take a break every now and then. 3d printing can get awfully addictive and if you are not careful you'll end up with boxes and boxes of printed things like I have.

Have fun!

BradBuilds (author)MikeTheSpike2015-11-27

Thanks for the great advice.

ABS will print on an extremely hot bed with bare glass, but my printer's bed can not do 110°, so I resort to glue sticks.

I definitely agree that bed leveling is crucial. I will add a step on that tomorrow.

ABS juice work well, but I liked Elmer's Glue more, because to me it seemed like less of a hassle.

My printer does have a case around it :) you just can't see it in the picture.

I know what you mean about taking a break! 3D printing is quite addicting, and I'm a little crazy about it.

Again, thanks for your comment, I love it when people take the time to respond to my instructables.

fdengine (author)2015-11-27

Great article. Thank you.

I've recently changed filament and found it difficult to remove the raft from the print. Can you suggest how I might overcome that?

BradBuilds (author)fdengine2015-11-27

Thanks for the comment! What slicer are you using to generate your raft? You might want less raft layers, and more cooling fan in between the raft and print.

Yonatan24 (author)2015-11-27

That was interesting even though I don't have a 3D printer!

Yonatan24 (author)Yonatan242015-11-27

I voted for you in the contests you entered

BradBuilds (author)Yonatan242015-11-27

Thank you! I appreciate it.

LouisP1 (author)2015-11-27

You forget the distance between the nozzle and the bed.

BradBuilds (author)LouisP12015-11-27

You're right! I did not cover all of the fails in this Instructable, just the most common ones. I may add on to it though, hang tight!

taylor.matson (author)2015-11-26

Hey cool to see that someone else is using the same method I'm using! I also learned a little in the article, thanks a lot!

BradBuilds (author)taylor.matson2015-11-26

No problem, glad I could help!

MarauderX (author)2015-11-26

Calibration is also one of the big problems and should be mentioned, along with quality of printer parts, filament types, etc.

BradBuilds (author)MarauderX2015-11-26

Yes, I agree. I plan to add on to this guide over time, and I hopefully will be able to add all that you mentioned.

DIY Hacks and How Tos (author)2015-11-25

Great 3D Printing Tutorial. Thanks for sharing.

Thank you!

About This Instructable




Bio: I make stuff. #makermovement
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