Tag: 3dprinting

Every once in a while, someone asks about Z offset within a Klipper configuration. More often than not, I advise people not to use it. But, it’s there for a reason, so what exactly is it?

I often see people do a mesh bed level on their printer, then try to set a Z offset from the bed to the nozzle of their printer, and then start printing. Unless you need a few grooves in your bed, I would not advise this method.

Z offset is used when your printer has some type of probe (BLTouch, for example) that is used to automatically create your mesh bed level. The XYZ distance from your probe tip to your nozzle tip needs to be determined and calibrated against, so that when you use it to create a mesh bed level you end up with a valid map.

If you don’t have a probe, you probably don’t want to do anything with Z offset.

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.

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.

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.

Are you printing thin parts that wind up being see-through in certain areas? 

For taller prints, it’s usually not a problem as the criss-crossing patterns from the slicer will ensure that your print is eventually filled in all the way. But for thin prints, it can be problematic to have a print with gaps in the ends. When I’m printing thinner components, I typically enable Cura’s overlap function. There is a “skin overlap” setting, as well as an “infill overlap” setting. I like to leave skin overlap at 10% and the infill overlap at around 30%. This is technically just overextruding under a different name, so you specific slicer may have a different name for it.

I was recently in a conversation in which one of the participants firmly believed that 3d printing would replace all other manufacturing processes. “In a few years, 3d printers will become so refined and advanced that no other technology will be needed.”

I’m not so sure about that. Becoming more mainstream and replacing some existing technology? Yes. Becoming the only manufacturing process and replacing all other technology? No.

Some of the most precise components that I’ve ever worked on are axles that are accurate to within a few nanometers. I would have a hard time believing that this same feat can be accomplished with a 3d printer. We’ll see, I suppose.

People sometimes complain that their mesh bed level keeps shifting. It may be. It also may not be. There are a few things to look at, then depending on the results of the investigation, there are a few things to adjust.

The two most common things that affect this are pretty simple to fix. As it heats up, your 3d printer bed warps and moves pretty significantly. It’s important that you establish your mesh bed level on a bed that has been thoroughly warmed up. Don’t start measuring just as soon as the temperature reads the right temperature. Your temperature sensor is just in one spot. I usually give it 5-10 minutes to “soak,” longer in the winter. The same goes for when you actually print parts. I know it adds time to the print job, but I have had a lot of success with adding a dwell command at the beginning of my prints to allow the bed to come to temperature.

The other issue that I commonly see is how parts are removed. A lot of people put their hand on the print bed while they scrape the part off of the bed. Your bed springs most likely will not return to exactly the same spot as they were before. By pushing down on them, you are most likely causing the bed to return to a slightly different configuration than it was before.