Tag: 3dprinting

Sometimes, the Bowden tube will pop out of the extruder. It can happen at either end, but I have found that it happens much more frequently at the extruder end.

This can be caused by two things:

  1. Clog in the nozzle. The nozzle gets clogged, then the extruder keeps pushing filament. Eventually, the Bowden tube will pop out to relieve the pressure.
  2. The teeth in the pneumatic coupling have worn out. In my experience, this comes from frequently removing the coupling and pushing it back on. If this is the case, you just need to get a new coupling.

I’ve seen some users having issues when using Cura 5. After doing some experiments myself, talking to some folks, and looking around through the help forums, it seems to me that Cura 4 profiles don’t carry over well into Cura 5. I’ve personally had the best success, and seen others with the same conclusions, when they create brand new profiles in Cura 5. The default action is for Cura 5 to import all of your Cura 4 profiles. It will work, but most users end up with ugly prints. I’ve found that Cura 5 works much better when I create brand new Cura 5 profiles and update them.

I read a user’s help request in an online forum that was interesting because it illustrates what can happen from time to time. The symptom that the user was experiencing was that there was way too much squish in their first layer of printing. It was almost non-existant.

They were stumped for a while as to what the cause was. In reading through their comments and the things that they tried, it turned out that they had a BLTouch. Basically, what had happened was that they had set up a mesh bed level manually, and then they allowed the BLTouch to override that stored level. A misconfigured BLTouch was the culprit, in this case. It was going through the motions, but it was storing an inadequate bed level, which was overriding the valid mesh bed level that they had stored previously.

This is probably the most difficult thing to troubleshoot, and I had it happen to me a while ago. After checking everything that I could think of, I tried a test print. It worked, ah, what a relief. I tried a few more prints. So far so good. Now to go ahead and try the overnight print. It failed at around hour 12 or 13. Ugh. Back to the drawing board. After going through several logs, I found a T0 error. Ah, something to look into.

In my case, it turns out that my temperature sensor wire was frayed. A $12 replacement fixed it, probably something that I should have done to begin with.

Live and learn.

Sometimes people want to create parts that have an aesthetic top surface. This can be done with the ironing function in Cura. It’s similar to ironing clothes, in the sense that it uses the heat from your nozzle to smooth out the top surface. One caveat, though, is that that it only works on flat top surfaces.

“My filament keeps snapping off!”

I hear this a lot. This is almost always the result of too much tension on the extruder. Most extruders have a knob that is used to adjust the amount of tension on the filament. Too little tension and your filament slips and you will have underextrusion issues.

Too much tension and your filament will look like it has bite marks on it or even snap off. Find the sweet spot in between.

I frequently get requests for help, or see help requests that are something like “my printer isn’t working right, how do I fix it?”

Such a vague description of what’s going on makes it very difficult to troubleshoot. It could be a setting, it could have something to do with the machine, it might even be your filament. For that matter, it might be the environment. When I first started I had my printer right next to an AC vent and it would throw off my prints every time the AC came on.

Most people in the help forums want to help you, but they need some basic information to be able to do so. What have you tried already? Provide some details about what is going wrong. Describe your machine, how long you have had it, any issues you have had with it in the past.

As far as some basic troubleshooting. Try a generic Cura profile (or other slicer of choice). Go through your machine and make sure everything is tightened and running smoothly. Make sure that your machine is calibrated and that your bed is level. Make sure that your filament is clean and dry. Doing these things will eliminate 75% of problems that you will experience with your printer.

You can get “bands,” or horizontal lines across your print for many reasons. Typically, it means that something is loose. It’s not always obvious where to start looking, though. I usually look at the roller bearings first. Then I make sure all the nuts and bolts are tight. Then I check the belt tension. Just keep going through your machine until you find something that wiggles more than it should and tighten it. It’s not a glamorous process, but you should be going through your machine periodically anyway. 

Salmon skin, I’m guessing most people have seen this.

In a word, salmon skin is the result of vibrations. Your nozzle isn’t exactly where the printer thinks it is while it is extruding, which causes variations in the surface texture of the finished part.

To improve your surface finish, go through the components of your printer and make sure they are tight. Like many things, some parts of your printer loosen up over time. It’s a good practice to make sure everything is tight periodically anyway. Make sure all of the bolts and nuts are tight, make sure that your roller bearings are smooth. Make sure that your printhead doesn’t have any slop in it if you try to move it with your hand, etc.

Regular maintenance checks should get rid of most of the effects of salmon skin.

Every once in a while I want to pause a print at a specific height. Sometimes it is to change filament, other times it is to add a weight or embed something into the print before it continues printing.

Frustratingly, many printers come with this functionality disabled. If you run into this roadblock too, you have a few options, all of them require reflashing the firmware.

  • Many manufacturers publish their firmware on places like github. You can download it, activate the settings, then reflash your firmware.
  • On Thingiverse, I have found many versions of firmware that people have created where they have updated to activate the most common settings. Just download and flash onto your printer.
  • Download and install something like Klipper, where you can easily enable or disable settings like this with just a printer.cfg file.

Whatever option you choose, it does require a certain comfort level with flashing new firmware onto your printer.