How can the precision of circular indexing be improved?
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One important feature of the machine tool we are developing and designing is its ability to divide parts into equal segments. The requirement for this division is that a circle can be divided into any desired number of equal parts, with a uniformity of rotation and an overall error per cycle of around 3 minutes of arc. We plan to use a stepper motor + worm gear reducer to achieve this. I would like to ask the experts on this forum whether this approach will meet the requirements, and whether it is possible to achieve a gap-free worm gear reducer The indexing operation must be automatic, with a time duration of within 1–2 seconds.
It can be implemented by referring to the principle of the FK125 indexing head. The clearance between the worm gear and the worm is adjusted through eccentricity. If it is necessary to achieve this at a higher position, a worm with variable lead can be used, but such processing is rather difficult. The following is explained: 1. In gear hobbing machines, worm gear drives are generally used for indexing, and the worms in these drives are of the double-lead type, also known as worms with unequal pitch, which allows for the adjustment of the transmission clearance between the worm gear and the worm. 2. As per your requirements, circular synchronous sensors are generally used for indexing; the principle is the same as that of linear digital displays. A division of about 3 degrees is no problem, and the key is to adjust the mechanical zero point and the electrical zero point. 3. Another option is to use a dual-spline disk differential indexing system. :victory:
Why not use a stepper motor directly? The more components between the drive section and the actuator, the lower the precision becomes.