I am a new user here, but I have already found a lot of information very useful. A little background before I get to my issue. After a 10 year hiatus, I am my astronomy club’s newly elected Director of Observatory Operations. My goal is to get everything that has sat dormant for nearly a decade up and running again so that we can do remote imaging with our Meade 16" LX200GPS. Everything has worked great thus far with SGP (imaging, guiding, plate solving) except for auto focus. Now to the issue.
The club owns, and I am trying to use, a JMI NGF-S with it’s absolute SmartFocus system and encoders. I have successfully used this autofocuser in the past with MaximDL, but I am not having any luck with SGP. When starting an autofocus routine, SGP sits at 0% until it finally fails. Looking back through the log, it appears that the JMI autofocuser is not reaching the correct position when asked by SGP. Even in the focuser tab, I have noticed that when I ask SGP to make manual movements (such as one step fine movements in or out) it typically moves more than the requested amount. I have attempted using anti-backlash as well to no avail. My guess is that it is a problem with the focuser itself, and not one with SGP. I thought I would ask for any advice here before recommending to the club that we purchase a new focuser. If buying a new focuser is the ultimate result, I will likely go with a new Moonlite Nightcrawler which I have seen multiple members on here use successfully.
I believe I have properly attached the log to this topic. Thanks in advance for any advice!
If you move to a new focuser, I would suggest you look at the line of computerized focusers from Optec rather than the Nightcrawler. With its array of knobs, LCD screen, etc. it seems to be much more designed for manual control than computer based control. For an observer wanting to mix visual use and imaging use, this might be a good combo.
Over the years I have used several of the Optec focusers and have been very happy with them. They feature small, precision step sizes, excellent temperature compensation and have a large load capacity. They also make a nice hand controller, if you want to use the focuser manually. But, perhaps most importantly, they are bullet proof with SGP.
The Nightcrawler may have knobs but that doesn’t mean that they are needed. I wrote the ACOM driver for it and there’s no need to touch the knobs or look at the screen.
That particular model uses encoders and when SGP validates that the focuser is at the requested position we often get values that are off from where we told it to go. Other applications don’t validate and thus don’t care.
As for the Nitecrawler, it’s a great focuser/rotator and works well. The Optec products are equally as good and both will work just great with SGP…so the decision is yours in that regard.
I have no doubt that the Nightcrawler works well when operated with the ASCOM interface and, as you say, the knobs and screen are then not needed. I suspect the primary use of the Nightcrawler is for ASCOM controlled focusing. So, it seems to me that Moonlight needs to have a version of the Nightcrawler that is knob and screen free – and reduce the price accordingly. A combo focuser-rotator that works well and costs less than $2K would be a great product.
Contact Ron and let him know. However I think that most of the cost of the Nightcrawler is in the hardware and removing the display and knobs may not save much, maybe not enough to pay for the redesign.