What is the main advantage of the SESTO SENSO 3's integrated encoder?
The integrated encoder allows you to manually turn your focuser's knob at any time without the SESTO SENSO 3 losing its electronic position. This suits users who switch between visual and imaging sessions.
Can I control the SESTO SENSO 3 without a computer at the telescope?
Yes. The SESTO SENSO 3 has built-in WiFi that creates its own wireless network. You can connect to it with any smartphone or tablet and use the Virtual HandPad to move the focuser and save positions without a computer.
How does the SESTO SENSO 3 attach to my focuser?
The SESTO SENSO 3 uses the included Self Centering Clamp 2 (SCC2) system. It connects to Crayford and rack-and-pinion focusers with 25mm, 26mm, 33mm or 37mm shafts without external brackets; a bushing fits the micrometric shaft, so the focuser needs a micrometric knob.
Can third-party software control the SESTO SENSO 3?
Yes. The SESTO SENSO 3 comes with an ASCOM driver (tested with ASCOM platform 7). The manual includes autofocus setup notes for NINA.
What happens if someone turns the focuser knob by hand?
With Automatic Position Recovery enabled, the SESTO SENSO 3 returns to the previous focus position after a delay you set (0 to 20 seconds). It is suited to public or educational observatories.
How does the SESTO SENSO 3 integrate with a PrimaLuceLab ARCO rotator?
It has an ARCO port: one short cable powers and controls the optional ARCO rotator, with no additional controllers. Turn on the ARCO enable switch in the settings.
Does the SESTO SENSO 3 get power from the USB-C cable?
No. The SESTO SENSO 3 requires an external 12V DC power source for motor operation. USB alone does not power it. A 12V power cable with a cigarette-lighter style plug is included.
Can I adjust the SESTO SENSO 3 for a heavy imaging train?
The Advanced Settings in PLAY set the motor's acceleration, run, deceleration and hold currents and the speed parameters. The manual notes that slips inside the focuser's micrometer reduction cannot be corrected by the motor; adjust the focuser to reduce slippage, and lower speeds reduce the chance of slips.
What autofocus step size should I start with?
The manual says a too-small step size is the usual cause of a poor autofocus curve, and suggests trying an Autofocus Step Size of about 500 with the 0.7 micron resolution, then adjusting for your system.
What is the difference between the internal and optional external temperature sensor on the SESTO SENSO 3?
The internal sensor measures the temperature of the motor itself, (values from 10 to 50 °C are normal in similar PrimaLuceLab focusers). The optional external probe is required for automatic focus temperature compensation.
What happens if my focuser's internal reduction system slips? Will the SESTO SENSO 3 encoder correct it?
No. The SESTO SENSO 3's encoder reads the rotation of its own motor shaft, not the final position of the drawtube. If there is mechanical slippage inside the focuser's 1:10 reduction gear, the drawtube will move less than commanded, and the step count will drift from the true position. The manual suggests adjusting the focuser to reduce slippage and using lower speeds.
