[MahiShafiullah]

It's always a trade-off! You could have more accurate sensors and motors that are more expensive, or you can have cheaper motors with no sensors and higher accumulated errors. Since this is more of a research project than a product, we went for a cheap robot with the slower-but-more-accurate approach.

[leptons]

Encoders are not that expensive and they don't have to be integrated into the motor. I've done this stuff before, it's not so costly and it really improves the entire system.