Makerbot Replictator 2 Prints Inside Dimensions Undersized

[david_nedlabs]

I bought a used Replicator 2 and have been using it for awhile to print various pieces for my job. I restored the settings to factory and am using MakerBot Desktop 3.9.2.1357, and I think all the parts are stock. Overall the accuracy of the printed part dimensions is really good, EXCEPT for the inside dimensions of hollow parts. See the attached picture of a test piece I've been printing to see what I mean by the inside dimensions. It doesn't seem to matter the size, shape, or resolution I print at, the inside dimensions are always 0.025" (0.64mm) undersized. It really seems that the software is running the print head right along the cad line of the interior wall, instead of just beside it to account for the thickness of the extruded line of plastic. This is very consistent across all layers of a print. I've tried the stock settings, as well as messing around with custom settings (e.g. number of shells, fill density, etc), and this issue persists. So, am I missing something, and more importantly, is there something I can do to fix this? Any help will be greatly appreciated.
testpart.jpg

[iDig3Dprinting]

Firstly, you do need to have some realistic expectations about desktop 3d printing accuracy.

Here are a few ways to reduce this error, although others may also have better suggestions.

1. try increasing the hole size to account for this error in your design software.
2. if you reduce the nozzle size then you will increase your xy resolution, this will reduce the error introduced by your path thickness.
3. Increasing layer height will also reduce path thickness i.e. tall and thin as opposed to short and fat exudate path.