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How to end overnight session

Sky-Watcher HEQ5 PRO Equipment Equatorial Mount Troubleshooting
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Dominic Wijker avatar
Dominic Wijker avatar
Hi!

I am wondering what people do at the end of an overnight imaging session. Does it matter if the scope just stops or do you let it slew back into home position? I am using the Asiair and had some power troubles. Using a poor power cable, the Asiair lost power during polar alignment slewing, so it kept on slewing and running my 8’ Newton into the tripod. Only thing i could do was to turn off my HEQ5 pro mount. I upgraded to the ZWO power cable which seems to fit better into the Asiair. However, a bit nervous to let the scope slew back to home position without supervision in the middle of the night….

And another question, do you let the Asiair turn itself off at the end or you let everything just running?

What else do i need to consider besides cable snags?

Thanks for any advice!
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Médéric Hébert avatar
Médéric Hébert avatar
Not using an Asiair, but simply telling it to stop slewing and wait for you to slew it home under supervision should be fine.
As for what else to consider: meridian limits on the mount. Make sure to never hit them as it'll "lock" the mount but having them will also prevent crashing into your tripod.
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patrice_so avatar
patrice_so avatar
Using APT for imaging, my Newtonian is automatically parked under trigger conditions defined in the plan to get on the side in a horizontal position, camera down side. That ensures that if the internal surface of the tube is got wet due to humidity, then drop won't fall neither on the primary nor on the secondary mirror. I let it dray that way. Then park in home position whenever it is dry and I cover everthing (with or without camera, depending on what comes next; the OTA and mount are 24/7/365 outside).
Frank Alvaro avatar
Frank Alvaro avatar
Previously when I used the ASIAir, and now with NINA, I end the session with the mount parked in the home position, pointing to the south celestial pole. The dew heaters are still running on the main scope and guide scope, so pointing  halfway between horizontal and vertical isn't an issue with dew formation.  I recently had a cable snag (fortunately I was able to rescue it before too much damage was done) so I have redone my cable management to hopefully avoid this happening again.
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Tony Gondola avatar
Tony Gondola avatar
Using NINA I end every session with a slew to the home position which for me, is pointing at the NCP. Everything is still powered up and running so in the morning, once the sky is bright enough I'll shoot my sky flats for the session, shut it all down and run out and cap the main and guide. Later in the morning, once everything warms up, I'll bag or pull in the OTA. Meridian flips and parking has been very reliable so I really don't worry about it.
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Médéric Hébert avatar
Médéric Hébert avatar
Tony Gondola:
Meridian flips and parking has been very reliable so I really don't worry about it.

It used to be the same for me until about 2 months ago, we got really cold temp (-30°C) and the power cable got stiff enough to get an intermittant connection to the mount, once it happend EQMOD lost the correct mount position and NINA wasn't able to recover. I got some better cable since and it didn't happend again. But since OP was getting power issue, I'd say that stop slewing and wait for supervision to go home is less hazardous.
David Stevenson avatar
David Stevenson avatar
I’ve gone hard at the automation side of things so using NINA, a command shell and some python scripts I 
  • slew to altitude 88
  • flats, and dark flats (let’s not start the debate on that)
  • return rotator to upright (protects against cable snags)
  • Slew to park
  • power down various kit rotator, dew heater, camera, light panel , filter wheel, wifi and focuser
  • last command by NINA is a shutdown /s /t of the NUC on which it running.


I did lose a USB socket on a camera from cable pull but just spent time and effort to avoid it going forward and I’m quite comfortable with it now. I also have automated the startup which works equally as well. 

I’ve given myself the challenge to automate the entire process end-2-end but got a way to go on that.
Tony Gondola avatar
Tony Gondola avatar
An area that's not discussed much is that a lot of faults and fails are caused by loose connectors. The USB and 3.5mm power connectors are far from industrial grade and are very prone to fail for a number of reasons. These are far from industrial grade and if improved would make everything a lot more reliable. The only connection on my whole rig that I really trust is the power connector to the mount. It's a two prong connector with a screw down cap. USB-c might be fine for a phone charger but we really need something far more robust.
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Monty Chandler avatar
Monty Chandler avatar
I use APT on a NUC mounted to the OTA's.   My time initiated "end of night" plan in session craft does three things.  Stops PHD2 guiding, Parks the scope to it's home position (preserves PEC in a eq6r pro), and warms the camera.
Frank Alvaro avatar
Frank Alvaro avatar
Tony Gondola:
An area that's not discussed much is that a lot of faults and fails are caused by loose connectors.


And another thing is the weight of the cables pulling down on those connectors. I now pull back a length of each cable and fix it to the hardware (camera, filter wheel, EAF, mount) with wrap-around Velcro so the connection is not being pulled down.
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Coolhandjo avatar
Coolhandjo avatar
I make sure it's parked home but leave dew heater running.
Aris Pope avatar
Aris Pope avatar
With these cold winter nights, end it with a shot of Irish Whiskey.
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