Wrong size of print with Cura 2.3 and 0.8 nozzle

[nigelwebb 0]

Hi,

I have just printed two different but similar parts that look like concentric rings joined with spokes.

Due to the size of the parts, and the very long printing time, I changed from a 0.4mm nozzle to a 0.8mm nozzle.

After printing I measured the parts.

Note: I require the parts to have a good diameter tolerance, something like +/-0.1mm.

All the outside diameters are correct to the model, BUT all the inside diameters are too small by about 0.5/0.6mm. This is the same on both different, but similar, parts.

I investigated the possibility that due to the size of the part (about 200mm) that this could be shrinkage, but that cannot be the case as the small inside diameters are out by the same as the large inside diameters (both 0.5/0.6mm).

Is this a known feature? Can it be corrected?

Thanks

Nigel