Category: Troubleshooting

I switched filaments. I’ve been meaning to change my nozzle, so while I was in there I did that too. When I printed a test print to make sure everything was good my first layer had holes in it.

Here is what I had to do to fix it.

  • my new nozzle doesn’t necessarily have the same height as my old one, so I releveled the bed and reestablished my mesh bed leveling.
  • my new nozzle probably doesn’t have the same heating characteristics as the one that I replaced, so I tuned PID.
  • my new filament may not feed in quite the same way as the old one, so I updated my e-steps.

Sometimes, you just can’t get the part quality that you want. For whatever reason, your machine just is not capable. Whether it is because your overhangs cause you to have to use a lot of supports which leave ugly marks on the surface, or your machine just doesn’t have the resolution to leave a good finish. There are a few things you can do.

  • Tune your machine. Make sure that 25mm commanded in the gcode results in 25mm of material printed.
  • Split your model into pieces. I print a lot of figurines for my kids. The hands and arms prove to be particularly difficult, as they need to be supported and they are small. When I cut the arms off and print them separately, I have much better results, then I just glue the arms onto the model.
  • Primer/paint. A little paint covers a multitude of imperfections. 

I’ve run across a couple of posts where people are having trouble with different things. Upon digging into it a little bit, I have found that they are using the wrong temperatures for the materials that they are trying to print with.

My post today is pretty simple, use the temperatures for the filament that you are using. If you are using PLA, use temperatures in the PLA temperature range. If you are using ABS, use temperatures in the ABS temperature range. Most manufacturers provide their recommended temperatures on the side of each roll of filament.

The optimal temperature will vary some and will depend upon your setup and your ambient environment, but you can’t run PLA at 260 degrees and expect a successful print.

When 3d printing, the filament actually is extruded when laying down a surface (obviously). But when the printer needs to skip across a hole or change layers, it actually retracts the filament into the nozzle for a short period of time. This is a good thing. If these settings are off or if the printer were to stop retracting, you would find a stringy mess of filament across every hole or void in your print.

There are two settings that I want to describe:

  • Retraction distance: this is the amount of filament that the printer pulls up into the nozzle. As you can imagine, timing, speed, and retraction distance are all related. If your retraction is set at 6mm, but your acceleration and speed are set so high that the printer only has enough time to extrude 3mm you are going to see some issues on your print, which brings us to the second point.
  • Retraction speed: this is the speed at which the printer retracts the filament. Set it too high and your extruder might strip your filament. Set it too low and you will have stringing.

One of the best ways to optimize your retraction is to print a retraction tower. However, printing a retraction tower requires you to update your retraction settings at certain intervals in Z. If you don’t have the ability to do this, trial and error is another alternative that gets you pretty close. Just update your retraction settings by a small interval and see if there is an improvement.

 

“Dad, the fence is down again!”

We live in a rural area and have animals. As anyone with animals can tell you, there is always something breaking, always something to do. Whenever possible, I like to have my boys (ages 10 and 13) fix it. I think it teaches them responsibility and gives them problem-solving skills. 

In this particular case, a fence bracket had broken. I could easily have gone to the store to pick one up for a few dollars. But miss out on this great opportunity to teach my boys something? Nah, not me. I had been looking for an opportunity like this. Something that needed to be custom made. A part that was pretty straightforward, but did need to be a certain size for it to function properly. This bracket needs to fit right, but it would also be forgiving. After all, it’s just a fence.

My boys had tinkered in Fusion 360 before, but it had always been just to create random toys and things that didn’t have a specific function.

“Go get my calipers from my toolbox and meet me outside.” We talked about how to measure parts to make sure they fit together and how to make sure that you have gathered enough dimensions. Then I turned it over to them to design. After many trips outside to confirm measurements, we had a design. Then we 3d printed one. It worked, the very first part off of the printer worked.

Whether they end up as engineers or not, these boys will have some valuable skills.

I had a mishap recently which required me to remove my bowden tube from my printer in order to clear out a clog. Upon reassembly, the tube kept popping out of the connector whenever I would try to print something.

As it turns out, there are tiny little “teeth” inside of the pneumatic connector that keep the bowden tube in place. When I removed it the first time, I smashed some of the teeth and prevented it from grabbing the tube properly.

In order to fix the situation, I replaced the tube itself (been meaning to do that for quite a while) and the pneumatic coupling.

During the summer, many places are hot and dry. As the weather cools off and most places start to have more rain, your filament can pick up some moisture too. This can cause stringing, zits, blisters, or voids in your print. You can avoid this by making sure to store your filament in a dry location and dehydrating it before you put it on the printer for use. 

For those using Klipper, they just released a pretty major change in the way that they store files. When I updated to the latest version all of my config files disappeared. As I looked into it, there seemed to be a lot of other people experiencing the same issue. It turns out that my files did not disappear at all. They were still there, they just had the incorrect file permissions. Here is how I was able to fix it after some Googling.

First, ssh into your pi and take a look in ~/printer_data/configand ~/klipper_config.

If your files are in one of those places, then you should be fine. If neither of those folders has your config files, then that is a separate issue entirely and you should reinstall moonraker and klipper. If you were able to see the config files in your ssh session, but not from your web access, then run the following commands in ssh.

cd ~/moonraker
git pull
./scripts/data-path-fix.sh

One side of print looks great, the other looks horrible.

A user recently posted this summary on a help forum. Temperature and cooling play a big role in part quality of 3d prints. The user had their PLA hotend temperature set too high. Additionally, they were underextruding and had their retraction settings incorrect. 

Many 3d printing problems can be resolved by going to the basics. Calibrate X, Y, Z, and your extruder. Make sure your bed is level. Run a retraction tower and a temperature tower. Make sure your filament is dry.

When you get layer shift, check your belt tension first. There are other contributing factors, but this is by far the biggest cause of layer shift. As your printer gets broken in the belts will tend to loosen up. Also, as the weather changes things might move around and loosen up too. Most belts on hobby printers are kept tight with a cam. Each one is different, but they all have the general idea that you tighten it by rotating the cam until the belt is tight.