The sliders' drives have quite diverse speeds. The X-MOTOR is the strongest one - it's the only drive that can work vertically, but it comes with the price of speed. It can go only 5 cm/s (c.a. 2 in/s). The STEPPER DRIVE is the most versatile - 0.4 m/s (c.a. 16 in/s) is enough for most applications. The fastest one - the SERVO DRIVE - is capable of really high speeds, up to 2 m/s (c.a. 6.5 ft/s), but is suitable only for long setups. It requires about 1m to accelerate to the full speed, so it cannot achieve its full speed on a slider shorter than 2 m.

The maximum sound level values in the table above might be misleading, as the speeds of the drives vary significantly. By analysing the chart you will find, that the SERVO DRIVE is the loudest, but only at its highest speed. The X-MOTOR is about 40 dB at 25-50 mm/s, where the STEPPER DRIVE is 34-36 dB, and the SERVO DRIVE is only 32dB. The STEPPER DRIVE is 40 dB above 300 mm/s, which is 6 times faster than X-MOTOR's max speed. And the SERVO DRIVE is 40 dB at about 800mm/s, 16 times faster than max speed of X-MOTOR and 2 times faster than max speed of the STEPPER DRIVE.

So, comparing "apples to apples" - the SERVO DRIVE is the quietest one.


Yes, you will need additional rings for PDMOVIE drives, as the photographic lenses do not have cine-style lens gears, just rubber rings for manual zoom/focus. It's the same style of focus gear ring, as you use with a manual follow focus unit.

Any ring will be OK if it uses standard 0.8 mm pitch (which is 99% of the gears on the market).
Choose whatever you like. You can use a toothed rubber band, that is easy to mount, or classic ring, that will enlarge the diameter of your lens ring and therefore increase the precision of steering (useful, if you're using photographic primes with small diameter).

For calibrating lenses, follow the KAIROS manual:
Note, that there's a difference in using lenses with hard stops and with a focus-by-wire engine.


If you want to update the firmware in your device, check if it's available on the download page:
If your device is on the list, download the software and follow on-screen instructions to connect and update your gear.