Complex sentence: Saying all the above I have never even been able to completely rule out the theory or test a super gyro at ordinary high mechanical speeds because of the high cost and dfficulty involved in building the complex mechanical system with sufficient robustness and precision.
Split into simpler sentences: Saying all the above I have never even been able to completely rule out the theory or test a super gyro at ordinary high mechanical speeds. This is because of the high cost and dfficulty involved in building the complex mechanical system required, with sufficient robustness and precision.