skybadger

Squeezed mine in when I did it last.

I've been running mine for the last 6 months solid and it's been reliable. I use a led lens to concentrate the sky FOV onto the sensor. I compare with a portable unihedron and astap Sqm calibrator and it remains consistent.

The problem with timers is the interval continually needs to change due to the changing alt, AZ movement rates. If you build yourself enough of a motor driver to drive the dome with switches, then you have enough to add the lesve dome control to for full dome auto control, or the velleman USB interface for the same. Both of these are open source on github or similar. Mines there too if you can do Arduino and some fairly simple soldering.

Glad to see you got it working. I use the same library for my esp8266 encoder dome tracker. All gpio s on that chip bar one can be used as interrupts. It's quite hard to use the i2c expander to do this but there are dedicated chips to do this which you can interrogate via i2c and I believe the teensy has two internal encoder interfaces built in for free. But I use the same interrupts to directly measure pulse frequencies up to 200khz .

You only need a few watts each, so much less than 2A.

Thanks Mike. It's not unsimilar to many other domes. A friction wheel driving on the underneath of the dome rotation may do your job. Alternatively if your rotating internal or external profiles are round-ish, a motor could drive on that surface. My dome drives on the internal edge but still uses power and control electronics for the shutter motors which are powed from solar & battery and uses Wi-Fi to communicate with a central controller PC . Hence allowing continuous rotation and independent power. Either way, take a look at cytron power controllers from the likes of the ro

Or maybe someone here can provide you an ascom compliant dome driver ? There are numerous large motor drivers out there, some for less than a tenner, that will work directly from a bidirectional switch. My dome shutter manual override works like that.

Hi Mike. As an engineer I will now say those important words , what are your requirements ? If you can rotate in a circle , a number of motors (between 1 and many) are probably easier to implement. They could be friction, belt and pinion or some other method of engagement but there are numerous open source and off the shelf solutions for that which would means your skills requirement can be kept to the appropriate level. Any details on the dome and physical layout ?

I'll have a stab.. Calculate the local hour angle for the meridian at Istanbul at 12-3=9am . Which star ? Ecliptic coords are ra and Dec ? Lower transition ,is that the same as upper and lower culmination for a polar star ? IE need more details please.

Agrees the stellar photometric way is the gold standard.it's just the way I read the post. I'm struggling to understand why the measurement is dependent on altitude, your signals are relative between star and background at any altitude. Perhaps you are saying the sky is brighter further from zenith ?

Just to check- are you using the unihedron to calibrate ASTAP or the way I would expect, plate solving to calibrate the unihedron ?

Also, why are you using a x3 Barlow when the quark has its own x4 built in ?

On mine I can see prominences without it being turned on. Solar disk detail becomes available with a low setting and solar self heating takes it past the tuned point so an erf is becoming essential . This is used with a SV80 Refractor so it's within the aperture range. Turn your heater settings right down and work through the range.

To balance my dual rig I use an extra long hand clamp against one end of the dovetail on the scope and the other end on the far end of the dovetail clamp to slowly push the dovetails through their clamps, retighten, and iterate until it balanced with axis clamps undone. The hand clamp addresses the high friction and weight on each dovetail, even when released enough to move. Otherwise I can't move them easily and smoothly by hand anymore. Measurement is possible by comparing motor current either side of the axis of interest. I haven't tried that yet though.

I recently had to do something similar for a M54 to M48 rotator - they are made and available overseas but by the time they are posted here the price is ugly and the delay is too. In the end I settled for making a M48-t2 rotator - its a t2 adaptor with a M48 front thread and a t2 rear. Something I really thought I'd be able to get hold of. I'm lucky enough to be able to make my own but there needs to be a place to get this sort of kit.