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There are many reasons why your 3d print might end up with blobs and zits on the surface. I want to talk about one specific cause of this: power recovery.

While this may seem like a strange culprit to be responsible for the physical deformation on the surface of your part, it does happen. Here is why. The power recovery function frequently accesses the gcode files that are being read to create your print. If you are using a slow SD card or a slow processor, it can cause your printhead to dwell for just a moment. During this time it is still extruding. For this reason, I normally keep the power recovery function off. 

Sometimes I am asked about how to change Cura settings to make supports easier to remove from the final 3d print. 

There is value in looking into support settings, but I usually like to back up a couple of steps. Here are a couple of things that I look at first, and then look at support settings.

  • Has the part been designed for 3d printing? If at all possible, keep the build process in mind when creating the design. Minimize the overhangs, for example, to reduce the number of supports that are needed. Obviously, this only applies if you have design authority.
  • Orientation. I play around with print orientation quite a bit before I settle on a final print method. Sometimes it’s obvious. For blocky functional components, there is often a square surface that is easy set onto the buildplate. Other times, it’s not so obvious.
  • Support settings. Once you’ve considered the 3d printing process, then it’s time to play with the support settings. These will be a function of your machine’s capability and tolerances. As a general rule, make them as close as you can get them to the print without having them welded to the surfaces.

I want to briefly talk about how a temperature tower is intended to work.

Every printer configuration and filament composition have a slightly different optimal temperature setting. The temperature tower is a method to find that optimal setting.

For PLA it’s usually between 195 and 205, so I start my temperature tower around 185 and finish around 215. You can apply the same logic to other materials. When you print it, let’s say that for the particular brand that you are working with that your optimal setting is 195 and you start your tower at 185. You will see a steady progression of improvement as your tower goes toward 195, then steady declining in quality as your temperature tower passes 195 and continues to heat up.

Filament, or rather, improper use and storage of filament, can cause a lot of issues. 

Most of it is porous. What this means is that it will absorb moisture over time, especially in humid areas. If you do end up using wet filament, you might notice a couple of things. It might pop or bubble as it is extruded as the moisture boils. It might extrude with holes in the filament for the same reason. Almost certainly, your printed part will have a very poor surface finish.

To remedy this, store filament in a dry area and, as an extra measure, dehydrate it before use.

I get asked this, from time to time, or see other people asking this question in help forums.

My answer is that there are as many price ranges for 3d printers as there are people using 3d printers. Some questions to consider:

  • Will you be using the 3d printer for business or is it simply a hobby? If your ability to pay your mortgage depends on your 3d printer, I would advise that you invest a little more into it.
  • What are your size/tolerance requirements? Larger machines and more accurate machines come with a larger pricetag, but this is one of those cases where you get what you pay for.
  • What will your components be used for? If simply to check fit of some type of prototype, then you can probably get away with just getting a machine that prints in plastic or resin. If you need the part to function in an assembly, you might need to get a more expensive machine that can print with more durable materials.

Clunk.

Clunk, clunk, clunk.

My printer is in the next room from where I work, and that’s what I heard one day. I watched it for a few minutes, but it didn’t take long for me to realize what was causing the noise. Every time the printer would move in Z it would clunk.

I’ve spent so many hours dialing in my settings, making sure that my table is level, etc but I forgot something important. Lube the Z axis lead screws. Make sure that they are tight in the motors and don’t spin unless the motor is spinning.

Someday, I plan on putting together a maintenance checklist. This will definitely be on it.

I had a project a little while back for which I wanted to use wood filament. After running a few test parts, I decided that I needed to increase the nozzle diameter because the wood filament kept clogging my off-the-shelf 0.4mm nozzle. After installing my larger diameter nozzle I ran a few more test parts and noticed that my corners weren’t closing properly. After going through many hours testing to find out what the cause was, I realized that my retraction was off. I had to decrease it significantly to get everything to work right again.

Moral of the story, most parameters are specific to the exact configuration that you have on the printer. If you change anything, you should check to make sure that you temperature, retraction settings, speeds, etc. are all appropropriate for the new configuration, or adjust them.

Material buildup. Your whole print is 20mm high except for in one corner of the print, where it seems that the nozzle is laying down extra material with each pass.

Chances are, it’s probably not. Most likely it is cooling, or lack of cooling actually. When your fan starts going out it doesn’t provide enough airflow to the part to cool it adequately. Then you get buildup in the areas of the part that are the most affected. 

I have a gantry machine with two separate z motors, each with their own endstop. The other day I homed my machine and the left side was significantly higher than the right.

Thinking that my machine was down and that I’d at least have to get a new endstop or something, I decided to go get some coffee and think it over.

When I got back and investigated further, I realized that the left side had come down on top of the cable that supplies power to the motor. A quick zip tie to make sure it stayed out of the way and a rehome and I was in business.

Sometimes it’s the simple things.