Wheel-holes for 3D printers?

[KatieK2]

I printed this in low resolution on a Makerbot Rep2. Unfortunately the wheels don't fit on the servos (ROB09347 from Sparkfun / a SpringRC SM-S4303R Continuous Rotation Servo). The wheels don't even slide onto the servo; there's no gap to fill. It seems like the star-shaped connection point for the servos seems to be too detailed for low-res 3d prints. I'm not sure how well it'd work even at a higher resolution.

Would it be possible to provide the wheel.stl files with holes lining up with some of the connectors that the servo comes with? With this, a user could connect the wheels to the servo connectors with wire or something.

The .svg file shows holes in the wheels, but these aren't in wheel.stl.