PrimaLuce Sesto Senso V.2

FWIW:  I can also highly recommend the ZWO EAF 5V  … it has worked perfectly for me on two totally different focussers.

Love it. The Sesto Senso 2 works very well.  For my William Optics GT 71, I needed an extra part due to how the focuser is attached. Because the GT 71 does not have a flat section on the barrel of the focus arm you have to make sure that the grub screws are tight and it is worth rechecking now and then. Had them come lose the other day and lost some overnight image time. The fact that it is attached to the fine focus side of the focuser means I get tight focus all the time. I use NINA for image acquisition and the Autofocus runs work fantastically well. I like that I can unplug the SS2 and use the manual focus knob if I want. That is not possible with the ZWO EAF I had before.  The EAF did not get as fine of a focus.   The calibration is quick when needed. The web interface accessed over the wifi link is easy and can use preset if you want to preset focus points for different eyepieces when doing visual astronomy. 
Over I love it. 

Clear skies.

Installled it, calibrated it, and forgot about it. No brainer, it just works.
Be cautious when installing it, alignment is critical.

Also here nothing but good to mention. I had the version 1 before and upgraded both scopes to version 2. The new flexible connectors make it much easier to install, the usb-c connector is a major improvement over the micro-usb (try to connect micro usb in the dark the right way round) and the wifi makes now manual control possible. Still planning to try to connect with ARCOrotator some time. 
v-curves are always solid, no backlash, all fine. 
Regarding calibration, note that the focuser does not have an absolute position as such. Any manual rotation of the focuser knob means the sesto senso does not know where it is anymore. So my standard practice is at the beginning of each session: rack focuser out quite a bit by hand, direct sesto senso to its zero position, than manually rack focuser completely in. Both focuser and sesto senso are now at 0 and from there you can move it to your usual in-focus position. All in all takes less than 30 seconds. 
this is different for the esatto’s. They have no manual override and maintain their absolute position. 
oh, another point to mention is the strength of the motor. My focuser has very little resistance. So when pointing upwards with a heavy camera on the back, it will slide outwards. The sesto senso applies constant power to hold the focuser in place and you can regulate how much power this is. It really keeps the camera rock-solid in its place. But the sesto senso needs to be on for that. So the zero-ing as described above should be done with the telescope in horizontal position. 
Hope you find this info useful. 

CS, Willem Jan

andrea tasselli:
Thanks to everyone who replied to my query. My idea is to eventually install it on a Moonlite 2" focuser and operate it with NINA in some sort of autofocus mode (e.g. when HFR increases above a certain threshold) so that I do not have it myself. Would that be possible?

Also, is calibration possible within NINA or needs be done with the PrimaLuce apps?

Thanks

Andrea

Calibration is done in the Primaluce app. Honestly though I've never bothered with calibration and its never been an issue. I've got one on a Moonlite, Feather touch, and stock focusers.

Can someone please comment on the power consumption of the Sesto Senso 2? After all you need it powered to keep it engaged.

FWIW a video describing the installation and calibration: (2) PrimaLuceLab Sesto Senso Autofocuser - YouTube.

Some small detail for those using a powerbox: the 12V power plug is 2.5 mm not the usual 2.1mm diameter.

Clear skies
Wolfgang

Thanks for that Wolfgang. Luckily there are adaptors.

Personally, I had a bad experience with an SS2.  Based on the other responses, perhaps it was an outlier experience.

I much prefer the Pegasus Focus Motors, and their unity software platform if you decide to use their other equipment (wheel, power boxes, etc…) is really solid.

Just as an update, The SS V1 I have installed is now working with NINA latest release. I haven't yet managed to do a full autofocusing calibration run but at least I can control it reliably from within NINA. The key was updating to ASCOM 6.6SP1, apparently.

Miguel G.:
a word of caution here. Please note I don't want to bash this device at all. I'm only sharing my experience. Maybe I'm biased cause I have a similar motor focus and also suffering the problem I'm describing. Mine is not a sesto senso, but it is also attached to the micro focuser knob. Depending on your focuser adjustment (not the motor, but the scope's focuser itself) and the weight of your optical train, you may suffer from slippage. It is not a sesto sensor's fault. A quick search on the internet will show you what I mean. The problem is inherent to the own design of the micro focuser knob and design. If you have a heavy payload, you may need to adjust and tighten your focuser tension. As you may guess, pointing to the cenit is the most critical position. I have an esprit 100 and my optical train weighs about 2.7Kg. I have had to adjust the focuser tension and improved a lot, but it still slips a little bit, but it's perfectly usable. Take it into account

So far I haven't noticed any slippage or focus creep with my focuser but I keep it pretty tight anyway. Besides, my imaging stack is around 1.5 kg so quite light.

As a follow-up to my previous messages. 

I will say that the PrimaLuce Play software is also amazing compared to the Pegasus Unity platform. I have a Pegasus PowerBox and a Flat Panel and have to interact with the Unity plateform each session. One day soon I will replace the PowerBox just because the Software interface is so bad. 

Rick

Monty Chandler:
The design of the sesto senso 2 attachment to the frame of the course knob and then to the pin of the micro focuser, makes slippage on a R&P focuser almost impossible.   It's securely attached.   Very difficult to move when powered.  Other focuser designs need a brake applied etc and slip easily.  Not a sesto senso issue imo. Cheers.

I don't know if we are talking about the same:
https://stargazerslounge.com/topic/366434-esprit-120-fine-focus-knob-slipping-and-sesto-senso-autofocuser-as-well/
https://www.cloudynights.com/topic/741786-sesto-senso-2-robotic-focusing-motor-not-so-good/

As you correctly say, the sesto is attached to the frame of the coarse knob, but the motor engages the micro focuser shaft. And that is the mechanism that may slip. It has nothing to do whether the focuser is rp or crayford. Take this: https://www.youtube.com/watch?v=smAn6jLFfWc
and replace the hand by a motor. That's what I mean. The video is an extreme case; but what I want to state is that under certain cases with a heavy payload and a not-so-well adjusted focuser, slippage may occur

EDIT: and, as stated, is not a sesto senso issue. Is a combination of a non adjusted focuser+payload+electric focuser design