This Spool holder is designed to slide onto the back of your MakerBot Replicator Mini and allow you to print with a MakerBot Large Spool of filament.
There are two versions of the bracket. One is designed to be printed on a larger printer if you have access to one, such as a Replicator 2. The other is compact enough to allow it to be printed on a Replicator Mini.
The tolerances on the Bracket to Spool Center are designed to be printed with PLA but should be fine in ABS as well.
To form a complete set you will need 1 bracket of your choice, 1 Spool Center, 1 Filament Tube Holder, 1 Bracket Pin and 1 Spool Pin.

Thanks to KennySpade for testing the sizing for the Replicator Mini+ and providing the STL/OpenSCAD file for the bracket with updated sizing.

The Brackets and the Spool Center were printed with 2 shells, 25% fill and 0.3mm layer height.
The Pins were printed with 2 shells, 75% fill and 0.2mm layer height.
The Filament Tube Holder was printed with 2 shells, 15% fill and 0.3mm layer height.
Support should not be required for any of these, there is break away supports designed into the brackets already in order to allow easy cleaning.
The short bracket is designed to be printed flat on the Mini's build plate on a 45 degree angle going from corner to corner. It is a tight fit on the platform but it does fit.