Calibration Cubes: More Harm Than Good?
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Too many people seem to calibrate their 3D printers with calibration cubes. I think this is a bad idea. In this video, I’ll show why calibration cubes are bad, how you properly tune your printer's dimensions, and how accurate the machines I have in my studio are!
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Chapters
00:00 Introduction
00:49 Anecdote
01:17 3D Printer Calibration
02:09 Accuracy of a 3D Printer
03:05 The letdowns of Calibration Cubes
04:10 3D Printer Skew
05:08 The CaliFlower
05:41 Calibrating my RatRig
08:01 Sponsor
09:40 Applying Calibration
12:10 Testing my 3D Printers
14:30 Which Skew is acceptable?
14:50 Uses for the Calibration Cube
#3Dprinting #calibration
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Really classy move helping Adam improve his calibration flower and pointing your viewers in his direction! Love it
But I love stepping on stray calibration cubes in the middle of the night
Maybe you want to add some spikes on top of the califlower? It could to a much better job than just simple cubes…… 😜
@@joachimeuler8269 Btw there is a retraction calibration model with four spikes. Best thing to step on in the middle of the night.
holy shit, I can tell this really hurts 🤣
Yeah gives me childhood flashbacks when stepping on legos back then
😂😂😂😂😂
I bought the Califflower back in Nov 2022. I appreciate the work Adam put into the design. Very much worth the small download fee.
tusjak is beginning the new design i heard so. he/she/they is been working on new gender for a while so its good to be back now. i spoke with he/she/they now a fewest day ago
@@uiopuiop3472 how can somone be working on a "new gender" lmao, you guys are so out of touch
tujsjak is makin it when here system is in dis agreement. @@nikoraasu6929
@@nikoraasu6929 hold up let him/her/them cook
@@nikoraasu6929 "Today, I AM A GOD!!!"
Firstly, I'm sold, but secondly, extremely casual mention Adam's cancer diagnosis! Funny delivery aside, love to see makers supporting makers
I love the califlower: after making tweaks, it's a single print that gives me confidence that everything is still working as expected. The older califlower is the only STL I've ever paid for, and I paid mostly for the support files. It was worth every penny, and the new design looks even better. Highly recommended if you are someone who mods their printer, even if you mostly print aesthetic parts: you're gonna need good accuracy on any new mod parts.
I especially appreciate what look like caliper supports in the design, as getting the calipers square for all the measurements is the biggest pain the ass through the whole process.
I never thought about skew correction on my 3D printer until I experienced a lid not aligning fully some weeks ago. The califlower has been a great help correcting for it as well as adjusting the shrinkage in the slicer!
Loved the video. I caught on to the Vector3D Califlower a few years ago and it really helped me tune my Ender 3V2. I saw another video awhile back from a youtube creator that was making collector card holders who first mentioned calibrating to a larger dimension due to the percent error you find with a smaller calibration cube. His explanation and Vector 3D really solidified the idea/theory for me. Its funny you had the same issue with measuring with calipers and got him to update the model. Thank you for letting us know there is a new model that we can snag now at no additional cost.
This is so perfect. Measuring mounting holes and creating a mount has been the best real accuracy test. I use a hole center calibrator. Checking a calibration hole (inner dimension) in an object is very different than measuring a cube. Hole center to center is the best method. Thank you for this video!!!
Feed those cubes to the shredder then the Artme3D. Just hope the Companion Cube isn't watching!
Who is companion cube,the cube with heart on it in portal 1?
@@arduinoblokodtr3699 You know don't you?
@@soundspark i don't know
@@soundspark i don't know
@@arduinoblokodtr3699 who are you, mr tidbit?
Good data, and you make a good case for sure! I've often printed my calibration cubes much larger, usually around 100mm, but I really like the additional checks and balances from the califlower! I'll definitely be supporting that project, and once I get my printer set back up, I'll have to look into all of the calibration methods pointed out in this video, especially skew!
Important point is: steps/mm is mechanical property that depends on belt type and gear tooth count. For the rest of 99% circumstances, calibration problems all about frimware and slicer settings.
True, but the belts pitch may change with tension
I don't know how more people don't understand this. You are right it's just fixed. If you have your rotation distance/esteps set up for your specific pulley setup - that's all you need. The rest is slicing and flow tuning.
Spread the message!! Don't fuck with rotation distance/esteps!!!!
Great Video- I've always used the Cube for quick- "Corner Bulge' and "Ringing" and Tuning in the "Top Layer/Ironing" but remember back in the early RepRap days guys saying don't use it for Measuring and it didn't take long to realize why,,,,, but here we are 10yrs later
All the Best-.
This made me happy. When I first started 3D printing, I printed out maybe 50 of the cubes. They were so new that... they were just cubes. No XYZ labeling or brands or whatnot. And I wasn't printing it for dimensional accuracy, I was so new I didn't think that was an important thing at that point, I printed them just to try and get a successful print. "Did the top layer look bad? Did it even get past the first layer?" etc. Fast forward: I've ignored so many of these tests for a simple reason - I just want to print stuff, not spend all my time calibrating my printed. I'm glad to see basically all the printers you tested have small skew and dimensional issues. You have a good point though: what is the acceptable amount of inaccuracy?
That's a different topic. But the 2 things on my mind:
1) a pet peeve that you're slowly smashing - ending hearsay in 3D printing. Enough of this "print one of these and you'll have have a good print" "it works for me" "run a temp tower" "no, temp towers are useless, do this calibration print" "make sure you calibrate your e-steps before you check dimensions" "wait, I though dimensions was for checking e-steps" wait wait... stop, can we just get an instruction sheet that we should be doing that produces a reproducible result? I remember you trying some service on Meltzone Podcast where you basically got sets of gcode to run, printed them, then answered some questions. Similar to a game called Q20/20 Questions, and at the end it gave you a printer/filament profile that was "perfect". There's a ton of calibration tests out there, some built into slicers, some separate, some free, some cost money... I'd love for some system, paid or not, that you could run the set of tests, get a profile or similar out of it, and move on. At the time that Q20 profile generator was discussed on Meltzone, it did basics. But now we have printers with flow calibration, input shaper, and more. And one thing not covered by any of them, is they don't take into account wear. Like, imagine getting a new printer, run the first run... it spits some random models out, you answer some questions... it auto-calibrates the machine (hey Prusa, when you gonna add that skew adjustment to the MK4/XL/Mini?), and then you move on. Have the slicer be able to do the same for filament. But then in a month or two, you can do a small print and find out if you need to rerun the calibration or not. A canary of sorts. I made the mistake of using the same brass nozzle for like 4 years, no carbon fiber or whatnot, but I finally went to replace it and found the 0.4 nozzle was closer to 0.55mm. Oops... but I had no real sign of this and it's not like I memorized how well things fit together from 4 years prior.
2) ERRF 2019 had a keynote speaker that was great to listen to: Adrian Bowyer. History and some ideas for things in the future... and he commented on this exact topic. That these were imprecise machines. And he proposed something... if the nozzle could tell when it makes contact with something in more then one dimension, it could be used to calibrate itself. Think: print the infamous 20mm calibration cube, it then cools, then pokes it... and finds out that it's 20.01mm, so it adjusts itself so it's next print is 20mm. Of course, this isn't some ground breaking concept... this is used by CNCs to find their source material, inspection systems, and in the 3-4 years since then (depending on how you want to measure time :P), we've gotten strain gauges on all the things and the Prusa XL literally does this to calibrate nozzle location between tool heads. It isn't fast, but at least you don't need to buy an external camera or similar. But the point is: it's there... right now. "We have the technology" we just need to use it.
You can also just use a dial indicator to check the distance of your travel moves. This eliminates any variables from extrusion width,, shrinkage etc. and purely check the motion system to see if a 20mm travel move is exactly what it should be. Adjust steps/mm from there.
I know not everyone has a dial indicator, but they aren't expensive.
This method will account for steps, but not for skew.
But yes, I have done the same on my first pinter.
@@KeksSektor Cal cubes don't check for skew either. The sides will still be parallel, and a 25mm cube isn't really big enough to check the edges with a good square. Correcting for skew is really it's own thing.
Great video, but the one part you definitely should have included is *why* it's a bad idea to adjust steps/mm: Because the steps per millimeter can be mathematically calculated based on the number of teeth on your motor's pulley and the pitch of the belt. The only way they can be off is if the belt is stretched.
If it's off, it's either shrinkage or under/over-extrusion, either of which should be compensated for in the slicer (as you pointed out).
Exactly... X/Y/Z steps/mm or Rotation Distance should be mathematically derived, not corrected based on inaccurate plastic measurements.
My belt with a 2mm tooth pitch around a 20 tooth pulley WILL move 40mm per rotation. If it doesn't, something is wrong!
This is also true for esteps on your extruder. Every filament behaves differently and the best way to adjust, as Stephan briefly mentions, is by adjusting the extrusion percentage in your slicer
Hm, but with the cheap belt gears you find in 3d printers the core diameter isn't as accurate as should be. See, if the 20 tooth gear moves 20 teeth around a diameter of let's say 12 mm, 36 mm travel will occur with one full rotation. If the diameter is just 0.2 under you get just 35.4 mm travel. And the rubber belt would just be fine with it because of the flex in the teeth. If we had precision parts we would be happier, but these parts are expensive
So I calibrated steps per mm with a caliper clamped to the head, moving towards a robust place of the frame. For each axis. 👍
@@sandrolauer350 That's not how cogged belts work. Unless you have it installed inverted with the flat side towards your cogged pulleys or are using smooth pulleys instead of cogged ones, it's impossible for a belt with a 2mm pitch to move more than 2mm per tooth. Even if it's loose and skips teeth, it's still going to move a multiple of 2mm per tooth.
I really love your takes on 3D printing, you have a unique understanding in engineering and that shows. I fell into this cube trap as well without even thinking about it... the effect of "this must work as so many use it".
I'm shocked at how thoughtfully constructed this is. The guide pieces to get precise positioning have been spectacular!
This, signle point dimensional calibration is my pet peeve.
Two points are an improvement, but I prefer 10-20, shrinkage isn't always perfectly consistent. I once designed calibration square that let you measure both XY shrinkage and skew with 40 data points (technically 38), the only downside was that it had limited capability for measuring internal dimension.
Hi Stefan, we are running a large professional 3D printing farm, and never ever done "calibrations" like this. We are printing some shapes that we have made ourself, to check skew and have a tool that measure travel of the print head manually, and part of maintenance is to go over the mechanical issues. We have slicing profiles (shrinking, material) that we now are dimensionally within our tolerances, which is within 0.1. Best regards, Annie
do u mind share the shape?
@@andrikurniawan531 its definitely one of circle/square/triangle
I had always made my own calibration blocks (usually modeled off 1-2-3 machining blocks) with chamfers and radii to avoid the issues you mentioned. The cauliflower looks great and I will have to go pick that up.
I haven't trusted prints for calibrating X, y and z rotation distance for quite a while. I bought a dial indicator with 50mm measuring distance and an accuracy of 0.1mm used and it served me well for calibrating lengths. Also I agree that the scew measurements with the califlower are tempting...
Gates GT2 belts are spec'd to >0.3mm every 92 teeth at a 6.6lbs belt tension. I do just over 7lbs for a passively heated chamber (~65c when printing with a bed temp of 105c). You can find the full spec sheet online rather quickly. The further the tool is from the motor pulley gear the more relative tension effects accuracy. Meaning if you have at most 0.3mm off than it will average out to just over 0.15mm.
Everything else is shrinkage and not having your machine square and tramed.
With that said, shrinkage is dependent heavily on temps, extrusion speeds (and cooling), color that effects material properties, etc. And you should never expect a perfectly demential print on the most precise printer as every print will have its own unique shrinkage/internal tension.
Thank You Stefan, your videos on these 3D printing topics are under rated for how clear and digestible they are for normal and casual hobbyists. Learn so much here about topics I dont see others addressing let alone offering solutions to! Thank You!
I've measured the outside dimensions of stepped features to do this a few times, back calculating the thickness offset for the extrusion, but the simple elegance of averaging the inside and outside is something that I feel silly for not having thought of myself.
Major props for letting the author of the cauliflower update his design, it's not one I've seen before but I've been meaning to my Voron even more dialed in and it looks like it'd be a big help. I'm fully in agreement with your conclusions. Steps-per-mm are defined by the gearing of your printer. Shrinkage adjustments, line width, etc will dial in a printer far better. And don't forget to print a cooling tower to dial in your fan speeds as well!
Stefan, I noticed these issues with the calibration cube myself a long time ago, but I chocked up the issues I was having with just personal error and mistakes. I feel ashamed and foolish for not having though that the print used to calibrate could be the problem. Thank you for this. I have already purchased the cali flower. I'm going to go tune my printer now. Thank you!
I always look forward to Stefen’s videos. They are always well produced and provided valuable information.
What an awesome video! Thank you for your knowledge. I will definitely be looking forward to tuning my printer for any skewing.
Coincidentally I just used the skew compensation in Marlin for the first time about a week ago. I recently finished a 3D printer build I started years ago (and kinda forgot in the corner) which has a very classic "printed parts and threaded rods" frame construction. But the printer I used to print the parts ~5 years ago had a somewhat tilted bed - resulting in a permanently skewed printer, no way to get it square without completely reprinting and rebuilding it. Then I remembered that there was this skew compensation nobody ever talked about in the Marlin config and gave it a go - works great!
The mark of a good scientist is not "I know everything" but rather "I do not know, how can I learn what I do not know", I used benchys and calibration cubes and still end up with errored prints and knowing that there is better ways to measure and calibrate, made me learn a new skill and I appreciate that, so thank you. I will try it.
Honestly this video was really helpful! I've been having troubles with my Kobra Max since now I'm trying to print parts that need proper dimensional accuracy and decided I'm going to rebuild my printer with properly adjusting and tuning in mind. I believe this will help me out!
Callipers can vary a fair amount in accuracy. If you get a cheap micrometer then you can use that to calibrate the callipers. Also, be aware that you must manually apply consistent pressure with callipers, while a micrometer should have a friction wheel that applies a set amount of force each time.
There are calipers that are called "pressure calipers." They have an extra dial on them that shows how much force you are putting the jaws. If you buy a new one made by Mitutoyo they are about $900. Also, using a cheap micrometer to calibrate your calipers is not really the method to use. Using a "standard" or even a gauge block will work very well. To each his own.
@@6milesup
You can use the micrometer to measure a test piece (such as the maligned 20 mm cube), then use that as your ‘gauge block’. Plastics deform much more than metal or ceramic under load, so by doing this you have a better idea of the final dimension if you are wanting press-fit accuracy.
It gets complicated fast, if you want to measure TPU etc. Maybe an optical method is better there. You could use your phone camera for an ad-hoc measure with a reference (e.g. your calliper set to a close value) and some pixel counting. Really depends upon how accurate and precise you want your results to be.
You can also use a dial indicator to just check the motion system directly. zero it on some part of the gantry, do a 20mm move, and see if it's exactly 20 mm, no printing required, and no shrinkage or extrusion width to possibly interfere with the measurement
Pretty sure caliper accuracy is more than good enough for 0.2mm layer printed parts...aiming for x.xxxxx level of precision with fdm is silly and unnecessary imo.
@@Fennecbutt
With plastics you can get away with less precision, but you still want enough accuracy for fitment. Errors compound, too. A small error here and a small error there can result in something that won’t fit.
Squareness / orthogonality of axes should also be considered.
I have skew problem for a few months now but didnt knew the term! Thanks a lot! My E3D toolchanger thank you for it!
Loved this video! I was struggling as well with skew calibration, I’m happy that I’m not alone 😅
Thank you for confirming my long held suspicions. I've never bothered to print a calibration cube because I wasn't confident that my cheap vernier calipers were accurate enough to make my calibration better rather than worse, but the Califlower being designed for standard 150mm verniers makes a lot more sense.
I've just bought the Califlower model, so I look forward to giving it a go once I've fixed my current Octoprint problems.
You should link videos (or another video) for the aforementioned: filament profile tune, optimal extrusion temperature, extrusion flow percentage, tuning retractions, and optimum pressure advance value. I have lots of different links for printer tuning but I always collect more advice because I want to get the best prints 🔥
Totally agree, that would be amazing, specially given Stephan's atention to detail and perfectionism. It would really help a lot!
Preach, Stefan! It's a fine test of the final result. But I made this mistake on my first Ender 3. Its travel accuracy was actually perfect, and I just needed to better tune linear advance for corners and expansion to account for edges and holes. Then every part was spot on everywhere to 0.05-0.1 mm.
I always kind of wondered about the error of measuring a small cube vs a big cube, but I never thought about the rest of what you talked about. This was a really neat video to watch.
Just ripped apart my 12V Ender 3 clone to upgrade it to 24V. This is very good advice on correct calibration after it's full reassembly. Thanks! 👍
I did really learn things there I was not aware :
Skew, differents thermal effects dependinf on each filament at least.
Thank you very much!
Yes, this was new to me! I was a cube user until I saw this video. Thank you for your time and videos, keep them coming.
When I first started printing I was surprised to see how many people relied on a simple 20 mm size cube measured with a cheap caliper to adjust the steps per mm. Having a good amount of experience with measurements I knew the result would likely be worse than leaving the default values. I'm happy to see someone else pointing out the issue.
Yep, the best investment in my shop is a (used) mitotyo caliper. The cheap Chinese crap always loose the zero after switching off and eat button cells due their bad power management.
@@matneu27 a WHAT caliper? if thats not a typo im pretty sure you got scammed.
@@ipadize oh I am so sorry that I made a typo and luckily you discovered it. I meant the mitotoyo (hope I wrote it right, the letters on my caliper are almost wiped away by heavily usage)
Impressive, finally someone with an understanding of stack up and GPS cotation. Great video
This is funny to me because I've never printed a calibration cube 😂
For me, I needed to make a thing. So I printed it with super low infill settings and then measured it. After that, I just adjust the size of the print in CAD to what works for the part while keeping in mind the allowable tolerances. But, I'm lazy 😅
This video explains alot of some of the problems I'm having with my modified ender 3 pro. I will have to make time to figure this out and I'm pretty sure I'll be able to get my printer working as well as it should be. Thanks a million.
Really, I mean Really, and I can't stress this more, YOU REALLY spoke from my heart with this video.
I never understood why you should ever tune your printer for dimensions with printed parts.
There are sooooo many, and I mean soooooo many influencing factors for plastic parts, especially in 3D-Printing that it just don't make sense.
Get a good dial gauge and measure the distance the printer is moving. And check the skew with other proper measurement equipment.
If you print different materials you will notice differences in measures, printability and so on and so on.
So thank you very much for this video.
Great video, thanks for this. 👍🏽👍🏽
Now I’ll have to go through the hassle of calibrating 5 self built machines 😬
Damn you!
I have never done it that precise. I happen to have my own test with a 15 times 15cm square that has a pilon that is 15 cm in height as well.
I always used that to check my printers but only after I suspected them, it is not a test i do as a standard.
Good video, I learned a lot.
I love the color Cube and feeding the numbers back into my printer with the same filament that I use all the time made them more dimensionally accurate and it was really wonderful. It is a lot of work but once you get those X and Y numbers Your Parts come out way better and it's worth it
Really informative. Always thought the calicube is not the most helpful thats why I started to calibrate alignment mechanically if necessary or print larger corner pieces with more precise numbers about rectangularity. Good to see that my gutfeeling was right. Thanks as well to point to the skew adjustment i didn’t knew the word but always looked for perpendicular adjustment😊. Thanks for all your informative videos!
Thanks for helping Vector3D. He's a decent guy and deserves your support.
Good to know there is a new Califlower version.
All the best for Adam!
I agree with your finding , I have in fact calibrated my DIY Core XY by measuring the movement in XYZ with a calliper and doing the skew calibration.😉
👍🏻 this looks great. I've never checked my printer (two trees sapphire plus) for skew. I've been using the dimensional calibration tool from luckypants to tune shrinkage values. It also works on the idea of measuring inner and outer and taking an average.
I've used the Calibration cross for many years and did buy the Califlower last year. While it's a great print and product, it was tedious to measure all the points.
Cudos to you for doing that on so many printers!
This is great info that I wish was common knowledge in the 3D-printer world. Thank you for another great video!
I have never understood why people calibrate with only the 20mm cubes. I like to recommend to at least also measure something larger, like 100mmand compare them. If both are off by 5%, steps may be wrong. If booth are off by 0.1mm, something else is is too blame. Like caliper accuracy or how you held it while measuring etc.
Skew is something I am aware of but haven't really looked into yet. On my old Wanhao Di3 machines I used a spirit level to make sure both rods where at the same height in both ends (in relation to eachother, not to the table). The ends where usually loose out of the box and they could sit at different heights.
Back when I came around the CaliFlower, this is all what I understood from its take on dimensional accuracy. Fortunately, my Ender 3V2 Neo has been updated through the time, and Professional Firmware has skew correction as well, so it prints flawless. This analysis was as always very good indeed.
Over the years I've not commented much on anything. But this one rang out to me. THANK YOU for doing this. So many things I've said in past finally said by someone that is listened to. Deffo going to look into this califlower I like the idea of it and not only is the price reasonable but a good cause. Hope adam has a good outcome from the news he got.
When i first started 3d printing i altered the steps per mm, but as i gained more printing experience I came to the same conclusion as you that it was not the proper way to compensate for size error as the majority of it is material shrinkage which varies. I've also found that there are tons of variables including temperatures when printing, i.e hotend, bed, enclosure or ambient temps.
I've also found the speed at which the part is printed can affect shrinkage. I think this has to do with the rate at which the filament cools on the part.
For example, I've printed a test part and then scaled it. Reprinted the part to verify that the scaling was correct. Then when i would print a batch of those parts the size would change. I suspect this is because the layers have more time to cool as the printer is moving from part to part every layer.
I was able to negate this by completing individual parts 1 at a time. Aka if printing 10 parts I'd enable individual part printing where it would fully complete 1 part before starting the next.
I guess my point is that if you want to print accurate parts there is not 1 set of variables that will work for all situations. You'll have to adjust based on what your printing.
I never trusted the calibration cube for size. It’s too small. Your analysis is spot on and I will revisit my calibration procedure. I will also purchase the calibration flower. Thanks!
Thanks for the video. Last time I decided to have a look at this 3d printer I have bought but never used (sidewinder x1). I checked what to do what to tweak and I found a video about using calibration cube. I was a bit "meh". There's a problem using small reference which gives you local accuracy while we need to check volumetric accuracy. But you explain this perfectly with your examples. The califlower looks great, will buy
I find those vids/topics fascinating, mostly cuz makes me realize how experience/knowledge dictates much of what one does. Personally, since the very 1st time I've started 3d printing on my 1st machine years ago, I've calibrated it on a per project/material basis.. for me this has always been a given, but then again I went on to study precision mechanics when I was 14'yo and thus have had a deep understanding of many different manufacturing processes and materials for literally decades... Since I also have an engineering degree on mechatronics/robotics, so CNC machines and such are just intuitively simple to understand and thus tweak. But I do realize many enthusiasts lack the same fundamentals, and this is what I like the most about the 3d printing community, folks often times share openly the knowledge and often challenge the "trends" in order to help each other to achieve better results... Kudos for the topics and analyses...
I will say thi tho, I do find both my i3Mk3s and P1S to be reliably precise, as long as properly calibrated for the material used, and still is not uncommon for me to tweak the models to compensate for inaccuracies of the machines, after all hobbyist 3d printers are not nearly as accurate/precise as professional grade industrial machines... Even so, w/ the certain measure of knowledge and care one can achieve amazing parts w/ these little machines XD
Хорошо сказал.
also, I hate when my phone wrongly auto-corrects me (like my comment above), kudos to machines that while maybe not as smart and thus very reliant on us to get things right (as of yet) at least don't pretend to be "smart" and f. us all the time on simple stuff (like writing a message or navigating the city)...(looking at you iPhone/Apple and others).. love my 3d printers cuz whatever tasks that don't need my input they do perfectly well, everything else they do _exactly_ what I command them to do...
My first big print was done on a friend's ender 3 max. A two peice custom designed matx pc case.
The parts firs together great and then at assembly I noticed the holes for the motherboard did not line up. Now I know the most likely culprit and am ready to tackle the project again also making some modifications for things I didn't realize till after placing parts in the case.
I disagree. As you state at the end, the Cube can be very useful if used properly. Just measuring X, Y and Z is barely scratching the surface. You can check skew with a square as well or measure diagonally as you mentioned.
I use the CHEP Cube for many of those references beyond measuring X,Y & Z
Spot on Stephan! The first time I used a cali-cube the size of it never felt comfortable. Far too small to make an impact to precision for larger parts and seemed a bit under designed to consider all of the mechanical movements of the printer and properties of the filament. Seemed like it was targeting a simple process, and likely fits a larger audience using a printer in a different method than a multi-material / part maker. Thanks for the reference to califlower; will check that out to setup each material. 🙏
I completely agree! Never found the cube useful for dimensions, it's just a quick print to get a general impression of the print settings.
Also, I really like this "mythbuster" type of video. There are so many of these wrong impressions in the community!
You're doing all of us a service :)
great point on no current systemic way to determine skew, happy customer of the Califlower supporting Adam who provided a great solution. Saves so much headache when designing functional parts.
Back when I made my first printer (a delta) I made a calibration shape that had a few different dimensions as well as reference angles.
I figured that if the first section measured 50.5mm and the second 100.5 then the steps per mm was correct but I was getting over extrusion.
If I was getting 50.5 and 101 then it was the steps that were off.
You definitely need more than one dimension per axis to know what is going on.
Amusingly the shape I made actually looked pretty similar to this but with a more open sides.
Great video! I fully agree with your outcomes. Thank you for looking at this topic through another lens!
Well, thank you for catching me - that's one step I haven't done with my new 3D printer (but I haven't gotten into prints requiring huge accuracy as of yet).
I totaly agree. Thats why I created the "calibration cross" on TV (precursor of the calbratin flower?)and proposed a material&heat bed shinking compensation for the Prusa slicer (was never accepted). By the way the most of the shrinking is exactly what you can expect from a part cooling down from heat bed temperature to room temperature with the corresponding coefficient of thermal expansion.
I bought my copy of Adam's Califlower when it first came out. Brilliant! Both my home machines are dialed in because of Adam's great work. Nice to see others in the community agree.
I used dial indicators to calibrate my axis, just use the full range (10mm in my case) of the dials and make sure to only move in one direction to prevent backslash from the belt. Takes out the whole material tolerances and only focuses on the mechanical parts.
I do the same. I also used the dial indicator to make sure every axis was adjusted square to each other. Once this is done, you know any error is from something else.
Yes, I do check it from time to time. The first time I did it was when I had the same problem with the lid not closing. Then after a while I did it again because the belt on one of the printer's axes was worn out, which resulted in an oval instead of a circle. Now I check it by printing similar models to califlower
Thank you!
I have been fighting step calibration myths like the mentioned for years now, but every youtuber made a video on this and keeps the myths alive.
E-Steps in particular are a very hard thing to explain...
Don't calibrate E-Steps, calibrate flow for each filament...
Use the steps from the manufacturer
X,Y,Z steps should only be dependent on gear ratios, belts and stepper degree, so imperfections are mechanical problems
100 percent agree,.
there's definitely a place for calibrating E-steps though, for instance, if you change components on your extruder that change the gearing, you need to change the e-steps. that way 100mm of filament is actually 100mm and not 112 or 95, then you can fine tune flow per material in much smaller amounts after that.
@@callsignapollo_ 100% true, but in most cases the manufacturer
will provide the e-steps for your extruder gearing.
Those are usually for 1.8° steppers, so in case it's a 0.9° stepper those needs to be converted.
The parts come out undersized not only because they shrink, but also due to wrong assumption. You assume that every tooth of 2gt belt has a 2mm pitch; however the belt is manufactured undersized, because it's supposed to preload to nominal pitch while minimising vibration and backlash. You notice that when you adjust the tensioners on your 3D printer, they go quite a way between the belt has its slack out and when it actually feels right, and all this tensioner displacement goes into stretching the belt. And there's yet more leeway, it's in millimetres, it's not at all minor. Unfortunately i forgot what the belt spec tension to size is, and it's going to be different between Gates belt and a Chinese belt anyhow, but from my memory you can't really achieve it without exceeding the maximum recommended lateral loading for your steppers, too much and they may not run smoothly or the bearings may seize up.
On a Cartesian driven printer, you expect the tensioning error to be quite anisotropic as well.
I'm actually working on a yet different way to calibrate printer XY/skew, it's not going to use calipers, or indeed a print, and i think it'll be better.
I will definitely buy the stl, thank you for your good work!
Absolutely fascinating. I learned a lot more about dimensional errors. I knew some about skew compensation (the MK3 did a decent job with that due to its initial calibration routine) but I didn't realize there were material shrinkage compensations in some slicers. It makes a lot of sense and is one reason even an older printer can get better over time.
As far as using the calibration cube - I had no idea people were adjusting their steps/mm for x and y with them! 😬 I always heard of people using them to fine-tune their extruder's steps/mm after an initial adjustment via filament consumption just to make sure walls weren't too big or small (which, obviously, still has material-dependent issues due to different overall shrinkage).
Oh, and one more thing - you should have seen my original plywood printer kit. The guy who made the kits made most of his own parts. Unfortunately, it used fishing line over threaded rod that he cut and drilled himself. The rod wasn't quite centered which introduced an eccentricity to the X and Y leading to very wobbly diagonals. No compensation for that! (Needless to say, I upgraded to a belt drive later.)
I love these deep dives - please keep it up!
this... explains a lot of the issues i had with some prints that i needed somewhat accurate a while ago...
I agree with the stance. Especially averaging the outer and inner dimensions to get the actual one.
been on the fence about picking up the califlower for a while, this gave me the push as I've been printing bigger things that need way more accuracy and I haven't been too happy with the fits.
I ordered the 3 axis version of the Califlower a few weeks ago on a whim as I hadn't seen it reviewed by others. Its a great idea and was fun to show skew from some of my printers.
I completely agree with this method and this video explains the multitude of variables and how to calibrate and square the machine quite well. I've tried to guide customers to calibrate their machines and most will just not do it at all and assume that the machine is already calibrated from the manufacturer. the only change I would make to the cali-flower is adding a relatively tall tower thus adding more accuracy to the Z axis. The wider, longer, higher measurements you can do will add more accuracy. It would be nice i the material doesn't matter and the measurement were measured at the center of the nozzle from a reference point and the software would compensate for the material and settings used.
Love the honesty of this videos
One very important factor to having dimensional accuracy is belt quality and consistent tension on the X and Y. I switched my ender 3 v2 print farm to all gates belts and tuned them all exactly the same using spectroid app to 115mhz. I also do skew correction and my prints are absolutely spot on. I have a tolerance of 0.1mm on all of my printers so they are all printing within 100 microns of each other.
I said this a long time ago. There's also expansion and contraction in the machine, belt tension changing, per filament spool differences (no two are exactly identical), z-offset, motor steps, acceleration and de-acceleration, etc. I always go for a +/- 0.2mm.
for steps/mm calibration I use some checkerboard placed rectanges to measure not only "outer" size, but also "inner" size, what eliminates extrusion impact. And I use 100 mm distance instead of 20 mm.
This was a great video thank you! Very informative as always but I found this one particularly interesting.
As for Core XY machines (i run a ratrig v-core 3 as well), you should be able to correct skew by balancing the tension of the two belts. I found it totally sufficient to measure the distance the left and right gantry joiners have to the corners of the frame. Checking for squareness is something I thought everybody does everytime they retighten the belts. I modified my printer quite a bit and maybe had to do it more often than most folks, though.
I put a lot of effort into finetuning my frame and my linear rails into something very close to true square (hand-tight screws and soft nudges with a plastic mallet will get you there, measuring diagonals repeatedly)
Just put something (any rigid object of appropriate size, really) in between one side of the gantry and the inside of the frame and jog to the position where it just touches. Then adjust the tension of both belts so you have the the gap feeling the same on both sides. If this leads to tension being noticibly different between the two belts, just loosen and retighten the screws that connect the gantry extrusion to the joiner pieces, and repeat the process.
In my opinion, there is no reason for software scew correction or to deviate from the nominal steps per mm in the printer settings ever, at least for extrusion built core xys. Different amounts of thermal shrinkage can be compensated for in the slicer in a much better way.
As for precise measurement of the frame diagonals, instead of buying very large and expensive calipers, it might serve better to wrap a tailor's tape measure around diagonal opposing beams. Put two flags of painters tape or sth on the overlapping areas of the tape measure and cut into the flags. Remove one side of each flag, so they form a hairline thin gap when the tape measure is held tight. wrapping it around the other diagonal, you can easily see even tiny differences when holding a lamp behind the slit.
Great video as always 👍😀
I Love your indepht approach.
I have the old Califlower, but have never used it.
Thanks for sharing your experience with All of us 👍😀
Your per-material scaling factors are in line with what I've seen working in a 3D printing-based production environment, which is reassuring. I wonder if we'll see a specialized filament for calibration with a minimal or precisely known shrinkage factor so we can still do these tests to figure out actual steps/mm
Skew was a big pain back in the earlier days of 3D printing. I started with an Anet A8 and the whole reason I bought a second printer was to rebuild the A8 into an AM8. All because of the massive skew that was impossible to get rid of because there wasn't any way to adjust the laser cut acrylic frame.
5:26 I prefer the calilantern, which is the version of the model with a z component! If you're going to measure a bunch, you may as well fix the skew on all axes. And yes, the shrinkage should be tuned for each material as well, once a base rotation distance has been set.
Yeah, going to buy the calilantern now. I've printed so many public STLs that didn't quite fit, never sure if it was the model or my printers. The biggest downer with 3D printing IMHO is making parts fit with post processing.
I felt like the Cali lanterns is harder to hold and get consistent measurements on
Very impressive information! So useful initially, but also for a quick diagnostic down the road.
Do you have a list of tests you routinely use after changing hardware, or for a new machine?
Please continue moving the field forward. You've made so many quantified advances!
Excellent and informative video. I'm glad I watched this, I need to calibrate my printers. I'll buy the Califflower and give it a go.
just purchased the file, i'll test this out tonight. thank!
Totally agree. I was so fed up with incorrect spacing, that i just made my own calibration test (including pocket holes for nuts). Thing is, deviation can vary wildly depending on the size of the feature. That's why i design most of my technical parts in OpenSCAD, i have multiple deviation variables (as a library) that i can apply to the part before it is sliced. This is also a problem, because now almost all of my work must be done in OpenSCAD. CAD programs today are definitely not dynamic enough to factor in FDM printing errors.
As usual, a great value video! My only concern about this calibration part is some lack of rigidity and the fact it is not checking the Z axis dimension nor skew... but the idea is still a great one. I really wish you do a similar video about the Cali lantern.
I would suggest the print of matching pairs of calibration parts (like your box / box cover)... To be able to check final accuracy once calibration is finished.
Yes.
Been telling people all of this since 2013. You are correct in every detail in this video.
I like Adam's design, I already made something similar but your joint update looks great.
Building my own ratrig this week, now I know exactly how I'll calibrate it!
I usually use the cube as a spot check for quality and not for calibration. But I could use a good calibration technique, and this looks like a good one to try. Thanks for sharing!