Gina

Not quite that far back!

You should be able to get KStars to slew to the object in question, then plate solve to find out exactly where you're looking. KStars should then slew to the right place. Further solves (if required) should get you spot on. At least that's how I understand it. I haven't quite got it working yet but hope to next time we have a clear night without the moon shining straight down the spout! If you start with the mount set to point to Polaris roughly, KStars should do the rest. Yes, I have an observatory with fixed mount. I stuck an "N" on the mount to show north. The second slewing position is obvious. I do have a GEM though and know nothing about A-Z mounts.

Glad I use the very popular SkyWatcher mounts (ASCOM compliant) and ZWO cameras as these are supported in INDI (+ KStars/Ekos). There's a vast number of astro products supported by KStars/Ekos/INDI but if you don't have any of these, things get more difficult. I only run indiserver and the INDI drivers on the RPi (currently v3B) and run KStars/Ekos on Linux Mint desktop indoors (Mint is a Ubuntu fork). I guess reverse engineering your astro gear to make it ASCOM compliant would be very difficult, Dave.

I've designed a specially shaped bracket to attach the chain to the open end of the roof.

I worked on remote control systems in my career (amongst other things). Technology was very different then though. (60's & 70's)

This thread is going to be revised and posted as a Blog. Currently further progress is being posted in my thread Getting back into imaging after a long break

Test successful! Connected motor to bench PSU set to 13.8v and applied power and (once connected the right way round) the motor opened the roof effortlessly! Maximum current was about 2A and generally around just 1.4A.

Been doing a bit on the observatory roll-off-roof. There was an aluminium peg that engaged in a hole in the wood frame of the roof at the east end to stop it lifting in a severe storm that was binding. I'm replacing that with a better arrangement so cut the pin off with a hacksaw. Also, with some newly arrived PTFE spray, I lubricated the wheels. The result was a very free moving roof. A light push and it continues going for several feet or until at the end of travel. On to the motor drive. I released the clutch on the motor to free the chain, pulled the chain through and connected it temporarily to the east end of the roof with a clamp. The weight of the chain was enough to pull the roof open. Decided to see if freeing the chain from the worm gear motor drive would allow my to close the roof by hand in the event of motor failure (the reason for choosing this special type of garage roof opener motor unit). I opened the roof about half-way, pulled the chain through to take up the slack and then (with the clutch free) pushed the roof closed with the chain going through the motor unit. Found I could do this quite easily. RESULT! Next is to try power on the motor and see how well it opens the roof. After that I shall design brackets to attach the chain ends to the roof framework.

Great! Thought that might be the case. Thank you.

Seen anything? Some small breaks in the cloud here.

Cloudy here.

The instructions say they need a 12v stabilised supply but mine is 13.8v. Is this really true - how accurate a 12v supply does it really need? If it really is 12v exactly I'll have to see if a buck converter will handle that small volt drop. I think a regulator chip might just. Another way would be to use two buck converters back to back, one high-low and the other low-high.

This is my main thread on controlling the roof :- Gina's Observatory Roll-Off-Roof Automation (from Page 7) but there's a lot of currently irrelevant information in it and I am about to write a Blog.

Until I get the drive chain attached to the roof and run the motor, I don't know how much current will be needed and whether full speed would be too fast or not. I now have a rain sensor and could easily connect that into the control system which would close the roof and report back to KStars/Ekos. With the widefield rig I don't need to park the mount before closing the roof but if I get to use the big MN190 it will definitely have to be parked before closing the roof. I have no imaging plans for the MN190 ATM.

As recommended by the late Per Frejval who obtained the motor for me I bought a proper H-Bridge motor driver. I decided on the Arduino shield version, Pololu Dual VNH5019 Motor Driver Shield, as that seemed an easy way to control it. That was 4½ years ago and I'm now using the RPi for remote control. The H-Bridge motor control has inputs for speed (by PWM) and direction and an analogue output for the motor current (each amp of output current gives 140mv of signal). Arduino has analogue inputs, RPi doesn't. This means a number of options. RPi linked to Arduino RPi direct - ignoring motor current reading RPi plus my own interface including an ADC Ideally, I would produce my own INDI driver and have controls for Open Roof, Close Roof and display lights for Open, Closed, Opening, Closing plus possible a light showing motor current very roughly. viz. Off, Normal, High and Limiting represented by Grey, Green, Amber, Red. Or I could have a linear display in amps.

That's very nice of you - thank you.

My automation won't cost more than a fraction of that.

I'm gradually getting better a bit every day and today I felt up to going out to my observatory and checking on the roll off roof. Found the cause of stiffness when starting to open - aluminium peg a bit stiff in hole in wooden frame of roof. I shall replace that with a better system. Once I'd started opening the roof with a lever I was able to push it right open quite easily - with one finger, in fact. I am now considering the remote roof operation as most of this is already done. I'm back!! Not necessarily firing on all cylinders but back none-the-less.

I can't help beginning to think again about my imaging rigs. It may be that I won't be able to handle large telescopes and the observatory roof currently takes a lot of moving by hand. It has become far more difficult to move of late and something must have happened to the wheels, I think. Whether I shall be up to sorting this out remains to be seen. Heavy engineering (albeit wood mostly) may well be too much. There is another possibility for widefield imaging, which is my main interest ATM and that's to finish my micro-dome observatory and DIY fork mount. This should be less physical strain but more mental strain as I work out all the maths of the design. Not sure I am up to that either. Typical!!! Just as I have got my interest in imaging back my health is stopping me

Gradually feeling a bit better with each day of rest but still need sorting out medically (that is all booked).

The moon is shining brightly and so is Jupiter - don't know where the clouds are and I don't care either - I'm just sitting on the settee watching TV until I go to bed.

I was planning on automating the ROR eventually but that looks rather unlikely now unless I can get my health sorted out. In fact everything depends on getting my health sorted out. What I can manage will depend on how things go in the next week or two and the results of numerous tests and the resulting procedures/medication.

That's what I do. I'm setting everything up ATM. I mean, I was. Trying to relax now.

I think this project will be on hold for a while. Need better imaging conditions and my health is causing a little concern ATM so I'm taking it very easy.

Doesn't look very good for tonight or the next week but things can change - presumably for the better as well as the worse. The moon isn't affected by the weather forecast though!