Q: Do I need to repeat this process for every material I plan to print?

A: I am going to punt a bit on this question since it’s not a quick response and once I upload more information on the steps to follow it will address much of your question. I can say that you should perform these steps with the material you plan to print the most with.  For example, if you calibrated with PLA you should have a solid calibration with any type of PLA moving forward.  Other materials printed with similar temperatures and similar volumetric flow rates have not been far off in my experience (i.e. PETG and ABS if you calibrated using PLA).  If you are printing in the 280-300C range I would definitely print a 1-wall and 2-wall calibration cube to check my extrusion.  I wouldn’t repeat every step.

Q: What are the best resources for tuning the other things you didn't cover (like linear advance)?

A: For acceleration the best singular location of tuning guidance I have found is the Teaching Tech Calibration website with the caveat that I don’t agree with how to perform the optional maximum feedrate calculation.  If you are going to do this optional step you should determine the limits of your extrusion system using the process that Stefan has outlined on his website (https://www.cnckitchen.com/blog/flow-rate-benchmarking-of-a-hotend).  Acceleration tuning is one of those settings that can become a never-ending rabbit hole.  My prints never exhibited artifacts of poor acceleration to begin with and when I did try other settings, I really saw no difference.  I spend a day messing with different settings and was no better off at the end of the day. I ended up retaining the settings I started with.

Linear advance has several good resources on the web to research.  Even if you don’t have a Prusa, I really like the workflow Prusa explains on how to tune linear advance so it’s worth a read even if you will not be following the process step-by-step.  If you don’t have a Prusa you will most likely be following the Marlin process.  Teaching Tech (https://teachingtechyt.github.io/calibration.html#linadv) provides a good explanation on how to use the Marlin k-Factor Calibration Pattern Tool (https://marlinfw.org/tools/lin_advance/k-factor.html).

Q: Also, you use Cura a lot in the talk - do you prefer Cura over other slicers? Does it depend on which printer you are printing to? What are the strengths/weaknesses of the various slicers? 

A: Each slicer program has its pros and cons and all three(3) of the slicers I mentioned in my demo are all great tools.  The reason I showed Cura the most during my demo is that I feel it currently supports more brands of 3D printers than PrusaSlicer and ideaMaker.  Both PrusaSlicer and ideaMaker are adding baseline templates for other printers all the time but Cura is still the clear leader with hundreds of 3D printers loaded in the software.  If you have a Prusa MK3s or Prusa Mini for example I see PrusaSlicer being the best tool to start with.  Going through the pros and cons of each slicer would be an extensive undertaking.  This might be a good topic for a future Hack Chat.

Q: Should I be calibrating e-steps and PID before I start on any of this? Is it necessary to calibrate these on all printers, even the mk3s? 

A: E-step (both X, Y and Z along with the extruder stepper) check/calibration is typically not needed for a stock printer since the baseline firmware is typically correct.  In fact, I would be shocked if any recent printer didn’t have the correct e-steps programmed out of the box.  When you would want to check or modify your e-steps is when you upgraded/changed your extruder.  If you think your X or Y axis e-steps are incorrect I would check belt tension before making changes to the e-steps.  Printing the 100mm calibration cube is a great way to check your X and Y accuracy but don’t do this test until after you calibrate your extrusion flow rate.

If you have never tuned your PID, then I would recommend doing it before starting down the path of checking/calibrating your printer.  Some 3D printers have this step as part of the baseline start-up and PID tuning is recommended any time you make changes to your hotend and/or part cooling.  Example: If you change from a stock brass nozzle to a hardened steel nozzle you should perform a PID tuning.  When I added a silicone sock to my Prusa MK3s, I need to re-calibrate the PID.  The Teaching Tech 3D Printer Calibration has some information on PID tunning (https://teachingtechyt.github.io/calibration.html#pid), however I think you will find better resources by searching “[printer name here] PID tunning”.  Here is a good instruction video that covers a lot of printers (https://www.youtube.com/watch?v=h9Rdid-T-Gw).       

Q: What are the signs that filament flow rate is too fast or too slow? I think your talk got cut off before you could get into this. You mentioned that extrusion depends on speed - do the slicers have a way of adjusting this curve? 

A: I would tell anyone to start their research on extrusion calibration with the post from Stefan on benchmarking a printers flow rate (https://www.cnckitchen.com/blog/flow-rate-benchmarking-of-a-hotend).  The data he provides shows that there is a measurable drop in filament extrusion (i.e. under extrusion) as you increase volumetric flow rate at fixed temperature.  I have started to perform the same test(s) on my printer(s) and to date I am seeing similar trends.  The only negative I can think of if your volumetric flow rate is to low (which would equate to having a very slow print speed, i.e. 5-10mm/s) might be bridging since you need certain amount of speed to bridge the gap.  To high of a volumetric flow rate will shown signs of under extrusion in your part and/or your extruder jamming since you are trying to push plastic through it faster than it can heat it up.  The only slicer that I am aware of having a volumetric flow rate input is PrusaSlicer which has a maximum volumetric speed (Filament Settings > Advanced > Print speed override) and that setting limits your print speed so you don’t exceed your maximum volumetric speed.  If you applied the findings from Stefan’s tests in the link above you probably would want to set the maximum to “9 mm3/s” since he shows a big jump in under extrusion with volumetric flow rates above this.  I would add that I would then would be testing my extrusion calibration cube at “9 mm3/s” since this would ensure that I was getting proper extrusion at this speed and anything slower than that I would be potentially getting over extrusion but the amount of over extrusions would be so minimal it wouldn’t impact my part quality.  Check out this link (https://www.printitindustries.com/pages/print-speed-calculator) for an easy way to calculate your flow rate (volumetric flow rate).    

Q: Regarding filament temperature - what are the signs that filament is too cold or too hot? Is it mainly stringing or are there other signs, like bridging quality? 

A: You mentioned bridging and I typically like to caution people from using bridging quality as a large driver of your print temperature.  Yes, a “bridge” feature will typically sag more at higher temperatures but bridging can also sag if you don’t have enough part cooling, your print speed is too high and/or you are extruding too much material.  For example, with PLA you are already printing using 100% of your part cooling capability (expect for your 1st layer) and depending on your printer there might not be enough part cooling to cool the bridge for that given temp/speed.  For improving bridge quality, I typically start with slowing print speeds down before turning down the temp.  Better indications of too high of a print temperature are part features look “melty”, I know that’s a super technical term but it’s my best way to describe it.  Overhang features sag, corners sag and small features look like blobs of melted plastic.

Too low a temperature will show up as your extruder skipping/clogging/jamming and/or you will see under extrusion in your part.  Most filament manufactures provided a recommend temperature range and a red flag for me would be if you are printing in the lower ¼ segment of the range they provide.  

Jeff, thanks for the great questions.  I will try to keep these responses as concise as possible since some of these could be pages long and I will incorporate these questions into the FAQ section I was planning on publishing.

Q: You mentioned in the talk that you use the same settings for 90% of your prints - what settings were those? I missed that part of the talk.
A: I am pretty sure you are referring to my comment on layer height.  I have found a 0.2mm layer height to be the best mix of quality, speed and strength.  Much of my printing is for technical/functional applications so appearance (i.e. lack of layer lines) isn't a high priority but getting part features of good accuracy is important.  IMO 0.2mm layer height makes very good-looking prints.  Stefan at CNC Kitchen (https://www.cnckitchen.com/blog/the-influence-of-layer-height-on-the-strength-of-fdm-3d-prints) has a great post on the influence of layer height to part performance.

Great talk, Eric!

You mentioned in the talk that you use the same settings for 90% of your prints - what settings were those? I missed that part of the talk.

Regarding filament temperature - what are the signs that filament is too cold or too hot? Is it mainly stringing or are there other signs, like bridging quality?

What are the signs that filament flow rate is too fast or too slow? I think your talk got cut off before you could get into this. You mentioned that extrusion depends on speed - do the slicers have a way of adjusting this curve?

Should I be calibrating e-steps and PID before I start on any of this? Is it necessary to calibrate these on all printers, even the mk3s?

Also, you use Cura a lot in the talk -  do you prefer Cura over other slicers? Does it depend on which printer you are printing to? What are the strengths/weaknesses of the various slicers?

What are the best resources for tuning the other things you didn't cover (like linear advance)?

Do I need to repeat this process for every material I plan to print?

Thanks for everyone who attend my demo today.  I apologize for the technical issues.  I will be populating the this project page and have decided I will re-record some shorter videos cover each segment as it's own video.