Cyliner structures perfect external dimensions, but consistently undersized on internal dimension?

[macua85 52]

Hey guys,

As per the title, any idea why this may be happening, and how to correct it? Is it just a case of designing in the inaccuracy to model? Ideally I'd like to fix mechanically or with settings, as I can't redesign other peoples parts that I print.

Thanks

[Labern 718]

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[yellowshark 132]

It is the nature of 3D printed circular geometry that the finished dims may well be too inaccurate for you, be that the inner or outer geometry. Our printers do not draw circles they draw straight lines. In my experience, which includes producing circular seals for an automotive suspension system requiring pretty precise dims to prevent fluid leaks, it is trial and error. Sure with experience you can get pretty close on first run by adjusting the dims but for an engineering application you will almost certainly need several attempts to get it right. I have seen diameter errors up to 0.4mm