PSA: START HERE! Calibration made SIMPLE & please SHARE User Tips!

Hi All!

Are you having print problems? This is for you.
Are you a regular who are here helping others? This is for you, too!

Help seekers - Consider reading this a “first step” before you start playing with settings. This solves many of the “problems” we see.

Regulars - This is a ‘call to arms’ to all the Regulars on here. Yeah, that’s you. Don’t make me call roll. LOL
There’s a problem plaguing us. Calibration is tricky. I want to make a guide to help those struggling as probably half the calls for help we hear can be solved but some simple steps. PLEASE CONTRIBUTE! But KEEP IT SIMPLE! Thx! - EDITS noted at bottom.

I’ll start the ball rolling with some of my Favs, and some tips to make this easy. I’m sorry it’s long but that’s me. Too much for a TL:DR. (Sigh)
But investing the 10-15 minutes to read this will really get you to speed much quicker than reading dozens of posts finding scattered info. :grin:
This is meant as a reference, not a “one and done”! Things interact, you may need to redo steps, especially if you change things like nozzles!

First Up - Bed /Adhesion issues. DO THIS FIRST even if you think it’s good!! Seriously, ‘New, out of the box’ is not necessarily aligned! These things are subject to lots of vibration and bangs in shipping.

Before a 3D printer printer can print right you must have a flat, level plate. The process is called Tramming but is commonly called (slang) Leveling.
It has nothing to do with gravity or position!!! A properly tuned printer can print mounted on a wall or ceiling. :astonished:
Tramming is making the print bed equally distant to the hotend (printhead) in all positions across the bed.
You must have a proper mechanical device before software makes any difference!!! So the “Automatic Bed Level” (ABL) must have a good bed position to do its magic. Period.

Bambu Lab (BL) did a good, easy guide here, and it must be done properly before you will get good prints, take your time and do it right, everything else depends on this being right, it’s quick:

Additionally. At this time (April 2023) there is a major known issue with the beds, a number of them have a bow or bend in the middle. You still need to do the above, maybe more so. That’s all on this here, it’s covered elsewhere! NO DISCUSSING IT HERE PEOPLE! I HAVE A PITCHFORK AND KNOW HOW TO USE IT.
Next Item - Filament Calibration - THIS is the next step to do
As a short (ha!) explanation: No matter how carefully built, 3D printers have many slight differences from each other. Taken together, that makes each machine slightly different! Hence, you need to calibrate it if you want good prints. BL printers are good out of the box. Make yours great.

Filament is what we’re printing with. You must be aware that each Brand is a carefully formulated Polymer Blend with additives to make it flow, reduce stringing, increase strength, and dozens of other factors. IT. IS. COMPLEX! Each Brand’s formulas are closely guarded secrets worth millions.

Therefore, each has it’s own properties and needs its own settings.
BL offers finely tuned settings for it’s filaments (most of which are excellent and reasonably priced). But batch variations happen so sometimes even those can use tuning for your machine. Even different colors from the same brand can wildly vary. Black, Red, and Yellow are ones I’ve see vary the most.

So, if you want the best prints (who doesn’t) you need to tune the Filament Profiles. The good news is it usually requires only once for each Brand with an occasional one for the odd color being a PITA. :stuck_out_tongue_winking_eye:

Those settings are saved as a newly named Filament Profile which you can then one click when you use that in the future.
Here’s where you open the settings to change them, the box at right end:
Edit Filament

So if someone says “change the Temp for that filament” that’s where it goes. To SAVE it you click the Save box (#1) then (#2) name it the Brand, Color and include the nozzle you used. A .4 nozzle flows differently than a .6 or .8. You may not need it now, but as you get advanced later you’ll be glad.

The Calibration Process
Everyone starts out with Bambu Studio, which works very well but it doesn’t help you calibrate basic things. Fortunately there’s OrcaSlicer which is 95% the same, Looks and works exactly the same. What’s different? Some advanced settings needed for complex prints, and a whole series of “two or three click and go” calibrations.

SoftFever, the Author of OrcaSlicer (OS) watches closely the changes made by the BL Studio team, as well as advancements with Prusa Slicer so OcraSlicer stays current but is independent. There’s a very active community helping him as well, and he stays on top of bug fixes and advancements in the field. If you want more detail, read this:
EDIT: Previously had relationships wrong. Per SoftFever himself (see post below) - " I don’t have any partnership(or collaboration) with Bambulab, nor have they sponsored Orca Slicer or me in any way. I think some people might have been misled after reading the quoted part."

Here’s the page for his Calibration help which is what I’ll be explaining next:

So I need to get OrcaSlicer. Where?
OrcaSlicer and Studio can reside on the same machine and don’t bother each other. They’re so similar some people use OS to calibrate a filament then put the profile in BL Studio. It’s up to you. You get it here:

Running the Calibrations
They are all very easy, just pick it and print, but here’s some tips.
NOTE: The settings are affected by the nozzle size! You must run a new set of tests and save for that nozzle.
Obviously a .4 nozzle can’t push as much plastic as a .8, eh?
BTW - It’s four times the volume of flow not 2x as it’s measuring cubic volume (three dimensions).

You simply (while in a blank new Project) click Calibration top left:
Then choose the item to run.

OrcaSlicer Calibration

I suggest you follow the menu’s order. Most filaments don’t need a Temp Tower so skip that. If you have poor prints after this is done, go back and do that one.

Here’s the ones I suggest:
Flow Rate
1.(Pass 1) - Pass 2 just fine tunes, I haven’t seen a difference yet, but some filaments need it I guess.
2. Do not change any settings, just pick off menu and hit print. Easy.
BUT - you must uncheck the Flow Calibration checkbox before you start printing. You leave this off when done!! It also speeds up your print start by a couple minutes. SCORE!

  1. Look at the rectangles that printed. Pick the one that looks the smoothest in the center. The Calibrations Tutorial show the pictures, but it’s sometimes hard to pick. Find the largest smooth center.
  2. Remember to save the setting before doing the next calibration!!

Pressure Advance

  1. Pick off menu and go.
  2. Look at the lines. Pics in Tutorial. There’s a section on the right and one on the left that you’re looking at (one is Acceleration, one Deceleration). You want the best line with no bumps. BUT You’ll find you must compromise as they’re rarely both the best.

Here’s the trick - Find the best of each and split the difference. If you can’t tell, count up until you find a problem then count down to a bad one. The good one is the center of them. :wink: Now do the same on the other side. Split the difference between sides, that’s the best.

This doesn’t make sense just reading, but with the print in front of you you’ll get it. The forum isn’t accepting pics. I’ll edit this when that’s fixed.
3. Remember to save the setting before doing the next calibration!!

Max Flowrate

  1. You need to find the Current setting for the Filament you’ve chosen.
    Edit Filament

Close window (don’t save) and choose test:
SoftFork Flow Test

A settings box appears, use about a little less as a Start value, like 16 start at 15. Go to some higher number like 30 (double). Leave Steps alone. Use a multiple of the step, like 15 not 16 or 20 not 22.
Max Flow Rate 2

  1. It prints a winding curved surface. Don’t stop it if it looks ugly!

  2. Examine the surface and find where it starts printing poorly. That may just be a major change in sheen. Find the failure point on the print. The end has markers to help, each big line is .5mm/sec3 (the Step value), but the preferred way is below, in the Slicer.

  3. Go back and look in the Slicer > Preview mode.

  4. At top Right Change (1) Line Type to Flow. Then (2) Scroll the Layer Slider until you (3) find the matching place where it failed and note the number. (You can measure with calipers and calculate, this is the easier way)

  5. Figure the new number. Make sure you a give a 8% - 10% margin.
    So if you got 19.52 as the last good line, then you use a value of 18.
    Reason - Even the best filament will have some thinner and thicker spots, and as well as other factors that require some “wiggle” room. :slightly_smiling_face:

  6. Enter the new number in the Filament Profile (Step 1 above) in the Max volumetric flow box and Save.

Be certain you do this test as last, as all the other tests will affect it. Some people that are perfectionists will do the whole set twice. I don’t feel the need for that level of pain … :grin:

This is one of the biggest changes to speed you can do!!

BL was very conservative in their numbers. This widens the “window” of speeds available when slicing. It also may let you print in Sport or even Ludicrous Modes when before it would fail!

Some may be the same as you started. OK, that’s what it is.

Have fun, and you Regulars, please feel free to correct me or offer your tips too!

EDIT: Added Pics and rewrote Max Flow Section, minor other corrections.

EDIT 2: Added Decimal in #3 Step of Max Flowrate. Thanks for the catch @ant ! :+1: Added “New” may not be aligned to Tramming. Added line to intro.

EDIT 3: Corrected relationship between BL and SoftFever. MY APOLOGIES! Sadly “life” changes took me me away from this Board and 3D printing in general right after I wrote this, :frowning: but I wanted to pop by and fix this part. With luck I’ll be able to participate here soon, miss you all!!

EDIT 4: 5/31/24 Please note the date of this! Still not as active as I’d like in the 3D world but wanted to note -
There have been a number of improvements to Bambu Studio & Orca Slicer in the Calibration stuff. Please check the Wiki’s of the one you’re using for details, but this remains a basic guide so have fun!


Thanks for all of that information. This post should be pinned by the moderators and required reading for all newbies.


Great tutorial, well done!

Just a quick clarification, though. I don’t have any partnership(or collaboration) with Bambulab, nor have they sponsored Orca Slicer or me in any way. I think some people might have been misled after reading the quoted part.

Other than that, the tutorial was fantastic.

SoftFever, the Author of OrcaSlicer (OS) works closely with the BL Studio team, and they routinely share code so he’s actually part of Studio’s creation but independent. If you want more detail, read this:


Thanks for this tutorial! I am slightly puzzled about the level of experience you expect from users here. I got 4 years of 3D printing experience but I never heard terms like “pressure advance” or “volumetric speed”… Maybe this was never an adjustable parameter for my old machine…

Would be great to explain these terms to understand the need for this kind of calibration?

One would think that part would have been edited out by now. I read this and started questioning the validity of the rest of what I was about to read. Thanks for clarifying this for everyone.

Ha! I feel your pain! I’ve been at this since late 2015 and still feel like a n00b!

Sorry for the long reply, had to withdraw from my work here right after this was written {Sigh}

There are a lot of vids on YouTube that explain those terms, I only popped by to do a quick fix of a major error, but if life treats me well I’m be back soon and I’d be more than happy to write up a guide on those “for the average person”. They really are game changers in how well (and fast) the machine can print, and we ALL want faster high quality prints, eh?


FINALLY fixed, Sorry about that! Been off the board since right after I wrote it.
OrcaSlicer is still forging forward at an amazing rate, thanks so much for your hard work, SoftFever! :+1: :+1:

Thanks for the Kudos, I hope to be back to write some more guides soon!

I wish it had been possible but I left the board right after I wrote this and just now got back on to fix it. SoftFever’s post made it clear anyway.
Working on my Halo … :innocent: but those stupid horns keep popping up randomly :smiling_imp:

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Wow…thank you for this.

I’m new to printing and have been putting this off until I had a better understanding because it seemed so daunting, turns out it isn’t, but that’s mainly thanks to this post. One thing I’d add is the math used to change flow ratio. I looked it up and so can others so it’s really not a big deal.

I do have a question though or maybe two. I’m calibrating eSun Yellow PETG (giving details incase it matters) and after pass 1, I chose 15 but then when I did pass 2, it looks like -9 is the smoothest. It seems like it shouldn’t swing back that much but I suppose that’s why it goes to -9, can you confirm? ALSO, am I looking for the smoothest looking, or the smoothest feeling? lol some look better than others but then some feel smoother than others.

Thanks again for helping out. You’re the real MVP!

Great summary and starting point, thanks for this!

I just ran through the whole thing with the Bambulab PLA Basic that came with the printer and turn out I end up at the values the profile had anyway :slight_smile:
The exception is pressure advance, the value still matches at 0.02 but it is turned off in the Bambulab profile. From the test results I would assume I should turn it on but I wonder why this is not the case as a default then.

Reading through this I’m not sure if the recommendation to first do the manual process followed by the OrcaSlicer or use OrcaSlicer in lieu of the Bambu Lab manual bed leveling. Doing both obviously won’t hurt, but does cost time.

Reference the Manual Bed Leveling the " engineering plate is the opposite is the opposite side of the PLA plate and is plainly marked. “But” (always a but [Behold the Underlying Truth]) because a user may have simply never had a reason to look/pay attention to whats on the opposite of the PLA side of the plate, I wanted to make a suggestion the manual leveling page explain the engineering plate is the opposite side of the PLA plate, but a quick look doesn’t show any way to make suggestions).

Just a quick clarification. On the first Flow Calibration, when the popup comes up, there is no option for “Flow Calibration” check box. Is that just due to version differences? I’m running 1.8.0.

Once my P1S is delivered I can’t wait to follow this.

I’ll add to it, and you can move it into the overall instructions. I am not a super experienced printer, but I spent a lot of time trying to get mine dialed in and learning how to calibrate it. With new filament I do the above, then I do a shrinkage calibration.

I like this model. Shrinkage tool by RutiluSS | Download free STL model |

  1. Set your shrinkage for the filament to 100%.
  2. Optional, set elephants foot compensation to .2mm (I do this because I have had elephants foot cause measuring error)
  3. Print the model
  4. Measure and enter in the below spreadsheet

I use this spreadsheet to figure the shrinkage for Orca slicer.

Shrinkage Calibration Tool Calculator v2 - Google Sheets

I also use it to measure for hole compensation. I have had really good results getting filament dialed in with this method.

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Sorry, spreadsheet has been shared

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I’ve made some minor changes to your spreadsheet.
Since I’m new to the forum as an active user, I can’t post links or pictures yet, but I’ll try to explain the changes I’ve made so you can edit your google sheets document and keep it nifty for other users!

I’ve basically added letters in parentheses (A), (B) etc. to each of the measurements both in the picture of the file and the “Dimensions” column. That way, it’s simpler to identify which measurement is which, as opposed to deciphering each dimension titles you’ve assigned. It’s really just a quality of life change. :slight_smile:

Hope that helps @jhorn78!

Edit: I am now able to post links and images, so here are the examples I was talking about.

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I know it’s a late answer - but seemingly you don’t have an X1, right? The “Flow Calibration” is what the LiDAR is used for, other printers don’t have that :slight_smile:

So, when calibrating a filament, the first step seems to be flow rate calibration. Should Pressure Advance be turned off (unchecked) during this calibration step?

Pressure Advance only affects stops and starts so just the edges of the calibration squares. Don’t worry about the setting and ignore the look of the edges, focus on the centers. Then take care of PA calibration properly with its own tests.

Makes sense, thanks! Another question:

For max flow rate calibration, it seems the racetrack is only 1 line wide and is considered an outer wall. In Process settings, the outer and inner wall layer speeds are different. Will the speed settings for outer wall affect the result of this calibration test?

My inner wall speed is 300 mm/s and my outer wall speed is 200 mm/s.

I’m assuming you are using OrcaSlicer calibrations or a similar test.

No, during the test, the speed settings from the Process preset are not used.

Ok, something else doesn’t make sene to me. If you look at the OrcaSlicer documentation for flow rate calibration:

In Pass 1, the initial flow rate of 0.98 was adjusted up to 1.029. Then after Pass 2, it was adjusted back down to 0.96726. This doesn’t make sense to me.

If 0.96726 is the “best” flow rate, then how come in Pass 1 the “0” or “-5” sample wasn’t chosen as the best since the final calibrated rate was lower than our initial rate of 0.98?