Printer Skew Correction

Question for the group. How much skew is worth messing with??

I just printed a the 100mm skew tower for Klipper, here are my measurements…

XY Axis…

AC = 139.85
BD = 140.03
AD = 99.41

XZ Axis…

AC = 140.88
BD = 140.43
AD = 99.38

YZ Axis…

AC = 140.32
BD = 140.81
AD = 99.26

Should I even mess with skew correction? If I am understanding it correctly I am right at or a touch less than .5mm out of square over 100mm. That seems pretty dang accurate to me. But I wanted to get the opinion of much more qualified folks.

@vicious1 this is your design. Would you say that’s good enough or would you mess with skew correction in firmware???

Edited to add the XY measurements. I had looked at everything wrong starting out. And it turns out I’m not too bad off.

XY .18mm off
XZ .45mm off
YZ .49mm off

Going to enter it all in and run the print again. Will report back where I’m at after the skew correction in a few hours.


Depends what you are making. For 90% of things that is surely fine. The larger the print the more it matters typically.

I use the temp struts as my test prints. I am beyond happy with 0.2mm error over ~140mm.

I am not understanding those numbers, from your tests, is that klipper thing?


If that is my bed I measure AD-BC. two diagonals.

The harder to fix test is the Z skew, also tends to be much further out.

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This is the test print…

and this is how its measured…

Hopefully that explains it better than I can lol. Everything I plan to print first off that really matters will be 50mm or so high. But I still would like it good.

So if I’m understanding correctly I should mess with it and try to get it lower than .2mm

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I mean, if you are getting ready to start on LR3 #3, I would go ahead and dial it in pretty good :grin:

Whoa. Looks like i need to go back and do that. Been running klipper for a while and never knew that check was there!!

While I do have “plans” for LR3 #3 (plasma) unfortunately that’s a ways off still. No more space!!! I still want it tuned in the best I can get it. I just didn’t want to find my self in a “Chasing Zero’s” situation and wanted to see what everyone else thought about where I stood. So far this printer is WAY better than when I ran this test on my stock Ender 5 Plus lol. And for it being something that I built from the ground up that’s saying something LOL

Its a good test to run for sure. Marlin has the same basic test. There are smaller/faster prints you can do to get the measurements. I prefer to just run this one and get it all done in one shot. This print took just under 2 hrs with 2 walls and 10% infill and a .6 nozzle

So, I have a tendency to be a little on the OCD side about this kind of stuff, so I may not be the best person to listen to, but…

Before I printed my LR3 parts, I ran through like 3 cycles of it until I think I was less than 0.5mm out. This was with Marlin though, and it was a pain to have to re-compile and re-flash each time to mess with all this stuff.

With Klipper, since it’s just a file change, who knows when I would have stopped…I guess when I got tired of burning filament, or until an adjustment quit making it any better…

Well I’m glad y’all suggested I look at it more. Turns out I had measured wrong. Well not wrong but wasn’t measuring quite what I thought I was. Adjusting measurements on the first post…


I think those numbers are fantastic. I would be fine with that. Also that is a great test part. Scale ti down to get a rough quick test, scale it up to get super dialed in.


Awesome. Well I ran the skew correction and have it running again. We will see if its even better!

Here is the link to the part. It has a 50mm and 100mm version along with the .step file

and here is the link to the klipper docs to check it out. when you get around to building your bigger printer you really should check klipper out!!

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Oh the bigger build is getting klipper for sure. I am enjoying watching all of you use it. Extruders just zipping around so smoothly.


I’m printing these skew test with a base speed in Super Slicer of 125mm/s. But I haven’t tuned accelerations yet since I haven’t figured out how to use the ADXL that’s in the EBB. I will say, while it was a HUGE PITA!!!, I LOVE the can tool head board!. Just the wiring alone is beyond worth the headache of setup. And if I would have just stuck with the SKR pro from the get go and used the U2C I would have been up and running in less than an hour. That setup is simple and well documented. Now I just need you to mod your fan mount to have a spot to mount these LED chips I got LOL

It is Truly heaven sent for printing!!

Mine suffered over a hundred. I reduced to 80 but other things increased speed like accel and ah shoot the corner thing! Cant remember what it is called!!

Jerk / Junction Deviation?

Ok round 2 numbers… After Skew Correction…


AC = 139.89
BD = 140.83
AD = 99.36

.94mm out (How did it get worse???)


AC = 140.41
BD = 140.73
AD = 99.45

.32mm out (improvement over original)


AC = 140.36
BD = 140.95
AD = 99.38

.59mm out (also worse than original)

Ok something’s fishy here. Time to check belts and make sure it got implemented correctly in the firmware. Good thing I marked all 4 belts on the edge of the core!

Isn’t the “corner thing” you mean “pressure advance?”


Could be! I was thinking speed and had just watched an old CNC Kitchen video talking about jerk lol

No pressure advance, just came to me. Significantly improves corners

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I resemble that remark, jerk that is, bahahaha. Guess depends greatly on who you ask :wink: