Lessons From 3D Printing
— November 16, 2019
This post talks about my experiences with 3D printing while using and Ender 3 Pro, what I’ve learned, misses and recommendations. My intention with this post will be to keep it up to date with my latest findings.
Calibration is important no matter what; to get good prints you’ll have to calibrate: Extruder steps (e-steps), flow rate multiplier, and PID.
Extruder steps “e-steps”
Depending on your printer setup, if it’s bowden or direct you’ll calibrate your e-steps differently. In any bowden setup it’s recommended that you calibrate the extruder through free air, this means that you’ll need to detach the tube closest the hotend, extrude and measure the distance of the filament, repeat the process multiple times until satisfied. Doing the calibration this way will ensure a proper calibration of the extruder motor in isolation. For direct setups the process is going directly through the nozzle.
Flow rate multiplier
Once you have your e-steps calibrated you’ll then fine tune things per filament spool, type, and or brand. The recommendation for this is to print the calibration cube in vase mode in one and two perimeters variants, then measure, average, and calculate your results to change the flow rate multiplier. Remember to measure only the top layer.
One additional calibration step per-filament and or brand that you’ll end up doing is printing the temperature tower. This will help you diagnose the preferred temperature for that filament. Once you know that, calibrate the PID to keep the temperature of your hotend as close to those numbers as possible.
What not to calibrate
There is a misconception that to gain print accuracy you need to also calibrate the X, Y, or Z motors, and the reality is that YOU SHOULD NOT calibrate them as they already are calibrated based on your belts and lead screws.
Bed leveling as crucial as it is, is something we struggle quite a bit as there’s not a go to setting that will let you know if you are doing it right or not, for most part we know that a good distance from the bed to the nozzle will be 0.2mm (a sheet of paper thick) to 0.3mm, some materials prefer to be more squished than others. Getting your bed perfectly leveled is a thing of practice and patience. Things I could recommend is to try to use mesh bed leveling in Marlin and using a piece of paper as a reference spacer to know how close are you between the bed and the nozzle.
Having good adhesion is tied to a bunch of things such as: bed leveling, filament materials, bed and ambient temperatures, how clean is your bed, and lastly bed surface material. PLA for example (theoretically) can be printed with the bed at room temperature but we know that adhesion is better at higher temperatures, and if your are having adhesion problems you should aim for a hotter first layer but keep the rest of the print below the glass transition temperature, that’s because once adhered you want to avoid your first layer to get soft while applying the next layers to reduce the elephant foot. In general start with a “cold” temperature and start raising it as you need.
Read the spool information, don’t follow the “default” settings on your slicer of choice, read the specs of the filament you are printing and do some tests such as the temperature tower to know where it work the best.
Assembling your new 3D printer can be daunting at first but current printers are not that complicated to assemble; apart from the assembly instructions that come with the printer it’s also recommended to do some searches on the subject as well as seeing some videos on YouTube. Some of the most basic tips I can give are:
- Make the frame (if any) square. Measure distances before tightening all screws and ensure things are not flexed
- Be wary about over-tightening the screws. Most of the frames are made of aluminum and the bolts are steel, if you over-tight the bolt you could mill the frame
- Belt tension. Ensure that your belts are enough tensioned, if too loose your circles could not be round, leaning prints, misaligned layers, etc…
- Check all of the wheels, and adjust all of the eccentric nuts as they are responsible of a fit movement of the carriages
There are not many things I can write about the nozzle that are not obvious. In general you’ll want to:
- Keep your nozzle clean
- Avoid crashes between the nozzle and the bed as it can damage the nozzle and scratch the bed
- If you see filament coming out the nozzle and curling pretty heavily into the nozzle it might be a sign of wear or damage and will need a replacement
While doing all of the calibration you’ll start to know your printer, one super important thing than can not be overlooked is to TAKE NOTES, I recommend using a Spreadsheet. Write down the amount of filament used per spool, once you start doing big prints that’ll help you know if you’ll have enough filament to finish. Write down the configuration of your printer for any given spool, and or any detail you might think you’ll need in the long run to compare. The more data you store the less time you’ll need in the future to retune things. Do lots of testing and annotate prints while you go. Print lots of upgrades for your printer and enjoy things.
Thanks for reading.