In my SCARA each arm is over 200mm long so, to get better positional resolution I decided to use an 18:1 worm drive to reduce the whole step angular resolution to 0.1?. Obviously I have no idea whether the design will actually work, nor whether backlash will overwhelm the designed angular resolution. But, I wanted to check if anyone thought that the speed of the arm would be sufficient even with the 18x reduction.