Troubleshooting¶

In this chapter I'll list some of the most common problems people seem to have and what to do about them. Of course this chapter won't cover all of the possible problems one would probably have to deal with, but at least some of the typical problems beginners struggle with will be covered. If you don't find the answer to your specific problem here, please do a research by your own - there are countless websites as well as YouTube videos out there.

(Note: WIP, so maybe come back another time as well ;) )

Troubleshooting Guides¶

There are many pages and troubleshooting guides out there to find, so maybe do a little research on that as well.
However, to offer you an easier start right away, I'd like to mention a few troubleshooting guides here as well:

• The troubleshooting page from TeachingTech.
• The Print Quality Troubleshooting Guide from Simplyfy 3D.
• The 3D Printer Troubleshooting Guide from Matterhackers.

If you're (also) looking for tuning and calibration guides, see the chapter "Calibration" for some links.

First Layer Problems / Print Comes Off¶

If you're having the problem that your first layer isn't consistent across the plate and/or the print doesn't stick on the plate, then it's most likely that your z-offset isn't right, your PEI plate isn't properly cleaned and/or you're dealing with a warped or tilted bed and therefore experience certain areas where the distance between the nozzle and the plate will vary too much.

• As a rule of thumb you can keep in mind that if the nozzle is too far above the bed, the prints won't stick and (depending on how far above the nozzle actually is) may result in a spaghetti incident (which is filament all over the place) or a blob of fear (which is a large clump of filament built up around the hotend).
  If the nozzle is too close to the bed, the filament will get squished into the plate too much and that will (depending on how close the nozzle actually is) provoke clogging as well as it makes it difficult to remove the printed model later.
  The first layer is crucial for a perfect print, so take your time and get your z-offset dialed in well.
  See the section "Z-Offset" for further tips and check out this handy reference as well for determining the perfect first layer. First tip: check the underside of your print - if you can clearly see or even vaguely identify individual lines, your nozzle is still a bit too far away from the bed.
• Of course you have to pay attention that you really cleaned the PEI plate of the bed properly using e.g. simple dishwasher soap (no balm or 'soft' soap as they often contain some oily ingredients) and IPA to make the prints stick to it.
  I personally prefer and highly recommend silicone remover spray (that's the stuff the guys are using who are painting cars on a professional basis to get off any oil and grease off the chassis before starting the actual paintjob), it just works great.
• Avoid touching the plate with your bare hands and fingers as that'll leave a tiny amount of grease onto the plate as well.
• Also make sure that you chose the correct temperature of the bed for the filament you're using. If the bed is either too cold or too hot, then the print won't reliably stick to it either.
  For PLA for example it should be around 55°C - don't exceed 60°C for PLA as that's already the glass transition temperature of PLA (means, that's where the filament starts to get soft). For PETG I personally have to use 80°C.
• Turn off the part cooling fan when printing the first (few) layer(s) and use the correct fanspeed depending on your filament (e.g.: PLA needs a lot of cooling, PETG needs usually less cooling).
• Once the plate is clean, the z-offset is dialed in and the bedtemp is correct for the type of filament, the PEI plate really works great. There's no need to mess around with some sort of gluestick, tape, hairspray or whatsoever.
• I'd also suppose to add a brim to your model (you need to do it in the slicer), which helps keeping the print staying on the plate a lot. This is especially useful for objects with a small base. You can configure the width of the brim in your slicer. After finishing the print, you just wait until the object is cooled down and then you can break/tear the brim off the object. If tiny amounts of the brim stay at the model, just use a sharp cutter.
• You also should check the functionality and position of the z-offset 'sensor' which is being used by the machine to set the initial z-offset automatically while doing the calibration procedure. So read around that section and pay special attention to the section "Adjusting The Sensor's Height".
  You still have to observe the first layer while it's being printed though and you most likely still have to adjust the z-offset on the fly while printing the initial layer!
• Also make sure that you trammed the x-axis gantry, so that the nozzle has the same distance to the plate across the whole area. This might not be enough though if you're encountering a tilted bed along the y-axis, so check the next listing.
• Wiggle the bed and check if it moves in the vertical plane. If it does, check the bolts and nuts of the bedgantry and check the SG15 bearings for perfect position. Most likely the wheels (or at least one) are a bit too far away from the aluminum frame. Adjust the position of the wheels then, but pay attention to not adjust them too tight as well.

Stringing¶

Stringing can be caused and affected by different factors and therefore can't always be avoided by adjusting retraction settings only. You can find countless articles about it, so maybe do a little research on it.
Based on my own experiences, the following variables besides the retraction settings should be taken into account as well as one probably doesn't think about them in the first place:

• The type of filament (PLA, ABS, PETG, TPU).
• The quality of filament.
• The moisture of filament: moist filament increases stringing.
• The printing temperature: too high as well as too low printing temperatures cause stringing.
• The feeder gear pressure: if it's too low, the gear can't grab the filament reliably and therefore can't retract reliably.
• The state of the feeder gear: if the teeth of the feeder gear which grabs the filament is kinda clogged due to debris of the filament, then it might slip as well.
• The quality and the state of the nozzle: low-quality nozzles as well as worn out and/or slightly clogged nozzles can increase stringing. Also the diameter of the nozzle has an impact as it determines how much filament gets extruded.
• The quality and the state of the PTFE tube inside of the heatbreak.
  As an example: stringing got way better after I replaced the stock PTFE tube with a Capricorn one, it seems that the lower friction of the Capricorn tube affected the retraction capability. Also a slightly clogged and/or deformed tip of the PTFE tube affected this a lot.
• Retraction settings, so the retraction distance and the retraction speed.
  Even though one would usually assume that higher values should/would be better to avoid or at least deal with stringing, it's not always the case. So instead of e.g. going higher than 1mm retraction distance at the direct drive of the Neo (which would provoke clogging), go much lower and see how it goes.
  This seems to be affected not only by the type of filament (flexible filament like TPU needs completely different settings than pretty hard filament like PLA for example), but also by the quality of filament. Often cheap filament is lighter and more flexible than high quality filament and therefore it needs lower retraction settings overall to achieve good results.
• The object one wants to print: certain objects just caused stringing, even tho I usually printed without any stringing. I'd recommend to print retraction towers with two cone-shaped towers as well, to get the different diameter into account as well.
• The settings of the slicer, like wiping, z-hop, outer- vs. inner perimeter and so on. There are many articles and videos about this topic, so I'd recommend to do some research on it for your specific slicer.

Holes And/Or Bulges In Layers¶

These are mostly signs of under- / overextrusion and/or a clogged nozzle.

• If you observe a regular pattern like a vertical line where these gaps and bulges occur, then it's most likely the z-seam. You could change the setting of your slicer for the z-seam to "random", but that'll lead to random artefacts all over the print. In that case you'll most likely also note these artefacts in other spots of your model where layers start or end.
  As you can't use Linear Advance with the stock firmware, there isn't that much you can do about this under- and overextrusion an the beginning and the end of a layer besides making sure that you calibrated the e-steps correctly. You might be able to tweak some settings in your slicer though and optimize it a bit.
• If you observe holes in layers, or even longer lines in layers where filament is missing, then it's most likely too much retraction distance and/or a (partial) clog you're dealing with (which also gets provoked by too much retraction distance btw).
  So I'd recommend to check the retraction settings and clean the nozzle by e.g. doing some cold pulls. If the problem gets a bit better but persists, I'd recommend to disassemble the hotend, clean everything, inspect and maintain it and reassemble it again. Also pay attention to the PTFE tube and make sure you reassembled the hotend correctly. Check out the chapter "Printhead" for further information.

Zits And Blobs¶

If you're printing from an SD card and you notice zits and blobs all over the print in a regular pattern, then turn off the resume function. It makes the printer stop regularly for a tiny moment when saving to the card which results in those artefacts due to the leaking filament.
Best would be to not print from the SD card and use an extra host running e.g. OctoPrint on.

'Rough' Look, Uneven And 'Bubbly' Surface Or Lines¶

This is mostly caused by moist filament. When the filament gets heated up in the hotend and gets extruded, the water 'boils' up and the damp releases which results in a pretty 'rough' look. Even tho PLA isn't that sensitive to moisture like e.g. PETG, TPU or Nylon, it still may be moist - even a fresh and sealed spool can be moist (due to the production procedure). The following picture shows a comparison of PETG - the left 'weird' looking skirt is fresh and therefore moist filament right out of the package how it came from the manufacturer, the right skirt shows the same spool after being dried.

You can also check if the filament is (way) too moist by extruding with the nozzle up in the air. Watch the string of melted filament which comes out of the hotend, right at the nozzle. Does it seem to be 'bubbly'? Do those bubbles even pop? If so, then it's definitely too moist.

The solution for this would be to dry your filament. You can either get yourself one of those (imho overpriced) filament dryers or use a food dehydrator.
If you don't have any of them, you can use the well-controlled solution we all already have: the heated bed! Just lay your spool flat onto the bed (maybe put it on some small wooden pieces or so to raise it up a bit) and cover it with e.g. a cardboard box where you poked in some small holes and which you also placed onto some small objects to raise it up a bit and create a small gap between the box and the bedplate for a better circulation. Then heat up the bed to the specific temp you need for drying the type of filament you want to dry. Let it sit for a few hours.

Don't use your kitchen oven for drying filament, as those are often not capable of heating at lower temperatures (many ovens start to heat at 50°C, which is already close to the glass transition temperature of PLA, which is around 55°-60°C!) - you can end up with a big clump of a melted spool and filament!

When storing your filament, use e.g. some vaccum sealed bags or containers and add dessicant. You can see the solution I personally am using here.

The Pattern Of The Infill 'Shines' Through¶

If you experience a regular pattern on the outside of the printed model, it might be caused by the infill. If you print the infill first and then print the outer perimeters, then the infill will 'shine' through so to say. So try to change the belonging setting in your slicer and print the outer perimeters/walls first.

Dark Pieces Of Melted Filament¶

If you see dark (like honey or even brown or black) pieces of melted filament somewhere on your print, then this is a sign of a clogged or (most likely) even wrong assembled hotend. It's caused by filament which stays in the hotend somewhere, gets burned and when it comes out it's dark.
Most of the time there is a little gap where the filament gets collected, like between the nozzle and the PTFE tube when not being cut or assembled properly.

The solution here would be to do some cold pulls first to get as much filament out as possible, then disassemble the hotend and inspect it. Pay attention to the PTFE tube as well. When reassembling, make sure everything sits in place as it should and the tube is long enough to hit the nozzle (and at the Neo it also has to go up to the extruder gear as well). The tube needs to be cut perpendicular as well.
If any gap occurs, the melted filament will stick there again and get burned and the problem will occur again.

Layer Shifts / Pushed Off Prints / Stuck Axes¶

As a rule of thumb one would say:

• If you're experiencing layer shifts or stuck movements at either the x- or y-axis, check the position of the wheels and the belt tension.
• If you're experiencing problems in the height or if your prints get pushed off the bed because the nozzle hit them at a certain height, check the wheels of the x-axis gantry which run along the aluminum frame of the z-axis as well as the lead screw, the anti-backlash nut, the alignment and the complete assembly of the whole z-axis.

But it's actually better to check all axes (not only the y-axis for example) for being set up and tuned in correctly. Check the position of the wheels (they should touch but they shouldn't be too tight) and if they roll smooth and nice (or if you feel any hiccups due to bad bearings). Check the belt tension - it shouldn't be loose but it shouldn't be too tight as well (ppl always say "tighten your belts", but it's not always that simple..). With the printer being switched off, move the parts at different speeds by hand and feel if it's a smooth movement or if you feel any kind of 'weird' and unusual resistance or hiccups during the movements. At the same time, everything should be 'stable' as well and there shouldn't be any kind of wobble. Also check your z-axis setup as well, as that sometimes can also cause problems like layer shifts on the x-&y-axes - if the nozzle hits the bed due to a wrong movement of z, then that causes layer shifts as well.

Generally speaking, everything should run smooth when you move it manually by hand. If you feel some kind of resistance or a jam at certain spots, check the belonging axis and the involved parts. Deformed and/or too tight wheels can cause 'similar' problems like a misaligned z-axis for example. See the chapter "Axes" for further information.

Can't Load New Filament¶

For loading new filament, you need to have the hotend heated up to the belonging temperature first - you can't load filament in a cold hotend, as it won't melt in there.

If you can't load new filament, first of all check if you pulled the lever on the feeder gear.
If you did so and were able to insert the filament but it seems that it's getting stuck lower down in the hotend, then you might hit the end of the nozzle with an edge of your filament. It helps when you cut the filament in a 45° angle and bend the part you're manually feeding into the hotend so that it's pretty straight.
If you still can't get your filament loaded, it's most likely that the PTFE tube inside of the hotend is clogged or deformed or that you have a clog in or above the nozzle somewhere. To clean, inspect and maintain it, you need to disassemble the hotend. Check the section "Disassembling The Hotend" for more information.

Blue Silicone Sock Comes Off¶

If the blue elastic piece, which covers the heater block of the hotend, came off, try to put it back on. This one is called "silicone sock".
It kinda insulates the heater block and should be used. If it's missing and the fan duct of the part cooling fan is pointing not at the printed piece, but at the heater block, then you even may face a "Thermal Runaway" error.
If it doesn't stay on, just get yourself some new ones. I'd suppose to get yourself the ones which are slightliy shaped different and have bigger lips, they wrap around the heater block much better and therefore stay in place better.
Read the section "Silicone Sock" for further information and to see both types for comparison.

Large Clump Of Melted Filament Built Up¶

If you had a problem with a clump of melted filament that built up around the heater block or hotend, see the violet expandable textbox in the section "Hotend" to get some tips about how to clean everything again.
Also check the belonging sections in the chapter "Printhead" to see how to assemble the belonging parts of the hotend (heater block, heatbreak, nozzle) correctly for avoiding this kind of incident in the future.

Debris On The V-Slot Wheels And Rails¶

Debris of the wheels is normal - to a certain degree.

As these wheels are made of POM and as they're running along the slots of the rails, wear and tear does occur. So if you see that some fine dust is building up, consider it being normal - wipe it off the wheels and rails, inspect the wheels if you can see any irregularities and you should be good to go again.

But: if you see heavy wear and tear like 'flakes' of debris instead of fine dust like shown at the picture below, consider it as not being normal.

If you encounter this degree of wear and tear, especially after only a short time of usage, you should check the position of the wheels.
Most likely you are running them with too much pressure against the rails, means, you need to slightly adjust the position using the eccentric nuts and turn the belonging wheels a tiny bit away from the rail.
The other possible cause is a misalignment of the wheels. As the wheels are running along that v-slot, heavy wear and tear occurs if they aren't positioned correctly and if they're running a bit slanted in the slots. This can happen if something went wrong when installing them initially. In that case inspect the position as well and check if the bolts, spacers and eccentric nuts are mounted correctly.

Debris On The SG15 Bearings And Rails¶

Debris of the bearings and rails can be considered as being normal - to a certain degree.

As both parts are made out of metal, wear and tear does occur.

Imho three main causes can be mentioned:
- The bearings are running too tight along the rails. - The bearings are misaligned. - The bearings and rails aren't lubed.

For avoiding this as much as possible, do maintenance regularly, which means cleaning and lubricating the parts. Also check the position of the bearings - if they're running too tight along the rails, an increased amount of wear and tear will be caused.

See the following picture where you can clearly see a wear and tear, in this case of the rail's surface. According to the user who took this picture, this is the state after printing about one spool of filament - which is absolutely not "normal"!

(add pic rails wear & tear)

The reason for this was most likely the bearings being positioned too tight to the rail. Insufficient lubrification also plays a role as mentioned, but in this case the user did apply lube.

Wrong Temperature Is Read¶

If an obviously wrong temperature is read (like e.g. 10° for the bed when you have 25° room temperature or even a negative temperature when it's obvously not that cold), then it's most likely that you face a faulty wire. The starnds inside of the wires tend to break due to the movement and poor quality, and when only a few wires are left, the resistance becomes bigger - which results in an obviously faulty reading.

Homing/Movement Problems¶

If you face homing problems of

• the x- or y-axis, like the printhead crashes into the limit switch and doesn't seem to stop trying to move (which most likely makes an awful sound as well), please see the section "Homing Failed: X/Y.
• the z-axis, then it's most likely either a wiring problem (like a broken wire or a loose or unplugged connector) or a faulty switch. Of course the mainboard might be defective as well, but this is more unlikely (imho) if you didn't create a shortcut or so.
  So first of all check if the little metal piece at the x-axis gantry which triggers the switch really is in the correct position to trigger the switch.
  Check if the wiring of the switch is correct and if the connectors are plugged in at both the limit switch as well as at the mainboard.
  You can also measure the wire with a multimeter to see if you face a broken wire.
  If you know how to use a multimeter correctly, you can also measure the voltage coming from the mainboard to the switch itself, it should be around 3.3V DC. If that's the case, then it's most likely that the limit switch itself is faulty.

If you face movement problems of

• the x- or y-axis, check the belonging wheels and belts.
  Are the wheels in the perfect position, can they turn how they're supposed to?
  Is the belt neither too sloppy nor too tight?
  Can you move the belonging part (printhead/bed) manually without feeling any kind of unusual resistance or jam while moving it along the axis?
  Everything should move smooth. Check out the chapter "Axes" for further information.
  If no movement occurs at all, check if the belonging motor is working.
  Check if the wiring is correct and if the connectors are plugged in at the motor and the mainboard correctly.
  If that's the case, you could measure the wires using a multimeter to check if there's a broken wire maybe.
• the z-axis, check the belonging wheels of the x-axis gantry which run along the z-axis aluminum frame.
  Are the wheels in the perfect position, can they turn how they're supposed to?
  Is the lead screw system assembled correctly?
  Can you move the axis by turning the lead screw manually without feeling any kind of unusual resistance or jam?
  Everything should move smooth. Check out the chapter "Axes" for further information.
  If no movement occurs at all, check if the coupler between the motor and the lead screw is tight and mounted correctly.
  Check if the belonging motor is working.
  Check if the wiring is correct and if the connectors are plugged in at the motor and the mainboard correctly.
  If that's the case, you could measure the wires using a multimeter to check if there's a broken wire maybe.
  Another problem might be the z-axis limit switch. This is an optical type of switch. So if the z-axis only move a tiny bit upwards or if it doesn't move downwards while homing, then it might be that the problem is caused by the limit switch system here.
  So first of all check if the little metal piece at the x-axis gantry which triggers the switch really is in the correct position to trigger the switch.
  Check if the wiring of the switch is correct and if the connectors are plugged in at both the limit switch as well as at the mainboard.
  You can also measure the wire with a multimeter to see if you face a broken wire.
  If you know how to use a multimeter correctly, you can also measure the voltage coming from the mainboard to the switch itself, it should be around 3.3V DC. If that's the case, then it's most likely that the limit switch itself is faulty.

Error Messages¶

In the following I'll list some of the error messages that might appear on the screen of the control unit.

As I personally didn't come across many error messages yet, please reach out via email (address can be found in the footer of the page) when you face an error message that isn't listed here! Thanks!

The Module Is Abnormal¶

When attempting to level and calibrate the z-offset of the printer, you might come across the following error message:
"The module is abnormal. Please calibrate the position of the nozzle and module."

This message can be triggered when the z-offset sensor isn't working or hasn't been triggered successfully.
(..add description & solution..)