Well, $12m breaks my personal best, but the independent limiter is only delaying the inevitable. You'll have just as many bugs in your hardware as in your soft

Well, $12m breaks my personal best, but the independent limiter is only delaying the inevitable. You'll have just as many bugs in your hardware as in your software: 1) Include software controls to limit motor position 2) Include hardware kill switch to prevent collisions. 3) Drive unit to the outermost SAFE motor position. 4) Motor limit drops into worm gear 5) Send unit back to original position. 6) Unit doesn't move as worm gear eats limit cable. 7) Since the unit didn't actually move, the software limits are now compared with faulty data. 8) Send the unit out to the far edge again 9) Since the software positions are incorrect, the software limits won't help. 10) Since the limit cable was eaten by the gear, the contact switch won't help. 11) Hear super-mirror array drive into concrete wall. Of course, having a hardware limit switch the trigger on an open circuit would have fixed that problem. Until the time that a faulty solder joint shorts the switch and the mirror drives into the wall. So you can add in a hardware encoder to check the physical position. Which saves you until the unit is manually moved next to the wall between runs without updating the position in software. Since the encoder only gives relative position, the software limits, encoder, and shorted limit switch still gleefully watch as you again drive the super-mirror into a wall.