What's an acceptable margin of error?

[RobertM]

I finished calibrating my Rostock MAX v2 as detailed in the manual with results I'm pretty happy with. Next I printed some 'calibration cubes,' the model was 20mm/20mm/10mm in the X/Y/Z respectively, using MatterControl's MatterSlice I sent it off to the printer. I printed this model twice, letting the bed cool to room temp before removing the part and reheating the printer. My results were decent by my accounts, but I wanted to get other people's opinion as I could imagine there being more tweaking I could do.

Print #1: 20.05mm / 20.13mm / 9.97mm
Print #2: 19.99mm / 20.12mm / 9.98mm
(Measurements are X / Y / Z)

I printed these in ABS (which I realize has a good amount of shrinkage, I read 0.7%) with the hotend at 230C and the bed at 80C.

The Y axis being the consistent outlier is still within ~0.5%, so am I seeing results of a well calibrated printer or should I be looking to do some more fine tuning? What do most people consider acceptable when printing calibration cubes?

[derzaubererer]

from what ive ecxperienced the small 20 mm calibration cube runs fine even if its not perfectly calibrated the greater troubles arrrise when you want to use more of your build volume (250mm+)

[RobertM]

Do you mean a larger print would help because the error would be exaggerated, or are you inferring that the build platform may be ill-calibrated and other aberrations will appear at outer regions? In other words, would you expect that if I printed the same cube off center, say by 125mm, that I may see a very different shaped cube? That sounds like a good test, something I'll try out tonight.

[derzaubererer]

Do you mean a larger print would help because the error would be exaggerated, or are you inferring that the build platform may be ill-calibrated and other aberrations will appear at outer regions? In other words, would you expect that if I printed the same cube off center, say by 125mm, that I may see a very different shaped cube? That sounds like a good test, something I'll try out tonight.

i tried this out and before using opendact i could only use 170mm radius now i can safely go to 250 and see the same results
but ive encountered a weird error after autocalibrating my infill isnt overlapping anymore and its looking like there is much more distance between each line.. mehh

[RobertM]

I found that the bolt at the top of the Y axis was slanted and causing the belt to ride up the plastic part that surrounds the roller barring. After adjusting that my prints all fall within the same margin, and since my original post I've printed some custom test shapes that span about 240mm and print accurately.

You mentioned the infill having gaps, I recall seeing that in Jay Couture's Fine Tuning video (youtube: https://www.youtube.com/watch?v=1fwwA2gfolo), hopefully that video can help if you care, sounds like you're happy with your current set up.

[derzaubererer]

I found that the bolt at the top of the Y axis was slanted and causing the belt to ride up the plastic part that surrounds the roller barring. After adjusting that my prints all fall within the same margin, and since my original post I've printed some custom test shapes that span about 240mm and print accurately.

You mentioned the infill having gaps, I recall seeing that in Jay Couture's Fine Tuning video (youtube: https://www.youtube.com/watch?v=1fwwA2gfolo), hopefully that video can help if you care, sounds like you're happy with your current set up.

thanks i fixed this problem it was due to my slicing settings not beeing on point