SESTO SENSO is the robotic focusing motor designed to be connected to the shaft that you can see in your focuser – by removing the coarse and fine knobs (it requires your focuser to have micrometrical knob) – without the need of external and uncomfortable brackets thanks to its Self Centering Clamp (SCC)! Most of the focusers in the market have 25mm diameter shaft and SESTO SENSO will connect out of the box. Other focusers may come with 26, 33 or 37mm diameter shafts: in this case we have the optional 26, 33 or 37mm adapters for SESTO SENSO. In this article we’ll see how to install SESTO SENSO robotic focusing motor on many telescope’s focusers, also in case you need to add one of the adapters.
In order to connect SESTO SENSO to the focuser of your telescope, remove the manual focus micrometric knob by unscrewing the screw normally present on the knurled knob. After pulling it out, you also need to disconnect the coarse focuser knob, by means of an allen screw on the knob. On some plastic-covered focusers, you need to remove the plastic to access the disassembly screw. Connect one of the bushings you find in the SESTO SENSO box (based on the diameter that fits your focuser) to the small focuser shaft of your focuser.
Now you can connect SESTO SENSO to your focuser by paying attention to centering the micrometric pin with the pre-assembled bushing on SESTO SENSO, until it stops. By using the provided allen screw, lock the 2 grub screws that fix the pre-assembled bushing on SESTO SENSO to the bushing you just installed on your focuser’s shaft.
Then, by using the provided allen screw, please fix the larger screw that fix the Self Centering Clamp of SESTO SENSO to your focuser.
Finally, use the allen screw to lock the 3 small grub screws to secure SESTO SENSO in position.
NOTE: After installing SESTO SENSO on your focuser, check the smoothness of the movement keeping SESTO SENSO powered off and then manually moving the focus knob of your focuser. The presence of SESTO SENSO will make the movement harder (since the motor is connected) but the motion must still be uniform. If you notice an uneven movement, repeat the installation procedure.
If your focuser have another diameter, you can add the 26mm (SESTOSENSO-AD26II), 33mm (SESTOSENSO-AD33II) or 37mm (SESTOSENSO-AD37II) adapters. Any other diameter won’t work. Please note that these adapters are compatible only with SESTO SENSO 2 and not with SESTO SENSO first generation. In order to install the adapter, first of all please connect the long bushing (the one that comes within the adapter box) to your focuser’s shaft and lock it by using the 2 grub screws. Please note, it’s normal that the other side of the bushing has no threaded holes.
Then take the red adapter and connect to your focuser, by fixing it with the provided screws.
Then you will be able to connect the SESTO SENSO 2 main body. First of all you will have to fix the grub screws that connects the internal flexible shaft of SESTO SENSO 2 to the long black shaft. Then you will fix the screws that fix SESTO SENSO 2 25mm Self Centering Clamp to the adapter.
NOTE: SESTO SENSO connects to several focusers that may have different machining and tolerances precisions. Focusing accuracy, especially when using automatic focusing procedures, depends on the focuser mechanics and not only strictly on SESTO SENSO. If your focuser has an important backlash, you can adjust the backlash parameter in the software.