How accurate should calibration be

I ran a calibration cube to see how it was and came up with the following on the three axis’s.

.07 MM
-.07 MM
.12 MM

which in a proper measuring system is (rounded up to the nearest thou)


It would seem to be small errors unless printing very large (for a 3D printer) objects IE: 10" across an axis which could give a larger then desirable error, .05" for a .005" variance. Yes I know a printer can be tweaked to give an almost 0.000" error but that seems to be an impossible tolerance for a printer to hold. What would be an acceptable variance for “Most” printing.

When I was taking machine shop in high school, keeping to 0.005" on all dimensions would get you an “A”. 0.010" would be a “C” and anything higher would mean that you had to start over. By this standard, you’re doing more than fine.

When I started working in the early 1980s and was involved in the manufacture of computer terminals, the specification was 0.100" across a 14" span and was essentially impossible, if I remember correctly, we couldn’t get anything consistently better than 0.250" for parts this size. I don’t think you can do much better know for thick walled plastic moulding and you can’t get anything 10" or so for thin-walled plastic moulded parts.

So, I’d say you’re doing really good although I’d challenge that the idea you’re able to keep that level of accuracy up for different plastics along with different feed stock lots, their shrinkage rates as they cool, as well as expansion over different operating temperatures and humidities.

I’d be interested in hearing what your application is where you require such accuracy over what I would consider a fairly large piece.

Honestly, I would consider acceptable accuracies for 3D printed parts to be in the range of 0.25% to 0.8% in the XY axes and 0.05% to 0.2% in the Z axis as I believe that vertically the stacked filament will tend to be more accurate.

So, for a 10" part, I think you’re doing pretty good if it’s accurate to within 0.025" to 0.050" at 72F (22C - room temperature) and if you need better, or you’re expecting operating temperatures that are more than 20C above room temperature, then 3D printing is not the appropriate medium for the application.

Hey there!

I think your tolerances seem decent at the moment. You can always play with them to try to get it a little bit tighter, are you printing any parts that would require such tight tolerances?


That is exactly the problem. Everything varies with printers so what is an acceptable accuracy level for general printing. Most of the prints I do are not that demanding, some have to fit together but I fudge them in post print. I am more interested in what others achieve and should I “try harder” to achieve better results.

The 10" part was just an example of the extremes I can print on an Ender 3V2 and the possible error rate. Most of my prints are smaller.

plastic. there is a limit somewhere. I do a lot of prints that need to be precise and get them really close but elephant foot, just extrusion width take some of the precision away. I often print a few .5%-2% different in size to get a better fit. I usually get it close then use slicer controls to fine tune.

To eliminate elephant feet as well as make the model easier to remove from the print surface, put a 0.5mm chamfer all the way around and in holes that will come in contact with the print surface.

I’m likely on the less diligent end of the spectrum when it comes to printer calibration. Other than E-steps, I’ve never calibrated any of the 3 axis on my Ender 3s. Results have been quite close, so I’ve been happy. Definitely not as tight tolerances though as you @Loosenut.

Surprisingly enough that is one problem I have never had.

I know that some people run temp towers and calibration cubes for every filament they use, sometimes for different colours but I never do. I have never printed a temp tower or one of those torture tests to see how far my printer will print an overhang without failing or even a benchy. For PLA I print everything that same and generally they come out in good shape.

Filament - 220c on the first layer 210 on the rest
Bed - 70 on the first layer and 50 on the rest
I print on glass and glue and I NEVER have curling. It sticks so well that it is sometimes bitchy to remove the print but I’m good with that.

Since I installed a CR_Touch and a dual Z axis (belt type) I have not had any first layer problems, I haven’t even check the bed for level in over six months and all is good. I installed the "Luke Hatfield " trick in the hotend (a short piece of Capricorn tubing between the heat break and tube clamp) so I haven’t any hot end trouble like blockages or filament floods either.

Everything is going great. WHAT AM I DOING WRONG!

I had to read your post twice to make sure I was not missing something, I thought you were doing things right…

i would not kick a gift horse in the mouth, :slight_smile:


I had that happen when I built my voron, nothing went wrong… I didn’t know what to do!!!

I read all these forum threads on “my printer won’t…” and I was feeling left out. I’m sure karma will catch up with me at some point.