Bushing

I noticed as I was building my Makerbot that there are several plastic bushings - that are not printed. This seemed to be a shame, so I thought I'd make a printable version of them. ;) (I suspect there are probably good reasons for not using printed versions at the moment, but there wasn't a good bushing design on Thingiverse that I could find, and it's a basic part...)

The OpenSCAD file is what was used to create it. It is set up so you can enter the sizes needed and get the correct bus